Development Actions and the Rising Incidence of Disasters

Development Actions andthe Rising Incidence of Disasters

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EvalBrief4-cover 7/16/07 2:34 PM

Development Actions and the Rising Incidence of Disasters

Evaluation Brief 4

June 2007The World Bank

Washington, D.C.http://www.worldbank.org/ieg

©2007 Independent Evaluation GroupKnowledge & Evaluation Capacity DevelopmentThe World Bank1818 H Street, NWWashington, DC 20433 USAE-mail: [email protected]: 202-458-4487Fax: 202-522-3125http://www.worldbank.org/ieg

All rights reserved

This Evaluation Brief is a product of the staff of the Independent Evaluation Group (IEG) of the World Bank. The findings, in-terpretations, and conclusions expressed here do not necessarily reflect the views of the Executive Directors of The WorldBank or the governments they represent.

The World Bank does not guarantee the accuracy of the data included in this work. The boundaries, colors, denomina-tions, and other information shown on any map in this work do not imply any judgment on the part of the World Bank orIEG concerning the legal status of any territory or the endorsement or acceptance of such boundaries.

Rights and PermissionsThe material in this publication is copyrighted. Copying and/or transmitting portions or all of this work without permissionmay be a violation of applicable law. IEG encourages dissemination of its work and will normally grant permission to repro-duce portions of the work promptly.

For permission to photocopy or reprint any part of this work, please send a request with complete information [email protected].

This Evaluation Brief was written by Ronald Parker, with contributions from Kristin Little and Silke Heuser.

v Preface

1 Chapter 1 Development Actions and the Rising Incidence of Flood and Windstorm Disasters

7 Chapter 2 Bank Lending for Flooding and Storms

13 Chapter 3 Development Investments at Risk to Flooding and Storms

17 Chapter 4 Engineering and Planning Issues in Managing Watersheds for Flooding and Storms

23 Chapter 5 Ecological Issues in Managing Watersheds for Flooding and Storms

29 Chapter 6 Implications for the Bank

33 References

Contents

v

Preface

This Evaluation Brief brings attention to WorldBank investments at risk. It alerts task managersto increases in the number and severity of floodand windstorm disasters resulting from environ-mental degradation, population pressure incoastal areas and mega-cities, and the possibleeffects of climate change. In particular, the reportanalyzes the potential risks to investments inroads, ports, storm sewers, and embankmentson the one hand, and highlights actionsundertaken to preserve and restore wetlandsand forests on the other. Finally the reportdevelops a set of findings to be taken intoaccount when preparing projects in countrieslikely to be affected by these types of disasters.

This report serves as a bridge between a 2006evaluation of the World Bank’s response tonatural disasters and two upcoming IEG evalua-tions, one on the environment and the other onclimate change.

This Brief was conducted under the leadershipof Ronald S. Parker, and the report was written byRonald Parker with contributions from Kristin

Little and Silke Heuser. Anna Amato providedresearch support. It was edited by WilliamHurlbut and revised for publication by CarolineMcEuen. In particular, IEG acknowledges thecooperation with the U.S. National Oceanic andAtmospheric Administration (NOAA) and RuthKelty’s valuable contributions to the researchprocess. We are also deeply indebted to PietBuys, who was taken from us so suddenlythrough a fatal accident, and to his colleague,Siobhan Murray, who supported us both withGIS and a regional disaster hotspot analysis. Wewould also like to thank Marie Charles, whoprovided administrative support.

This report is based on a database of projectinformation with all the available information onevery Bank project that had disaster-relatedactivities. This database has since been turnedover to the Sustainable Development Networkfor continuous updates.

For an expanded version of this Brief, includingappendixes of supplementary information, visithttp://www.worldbank.org/ieg/naturaldisasters/.

1

CHAPTER 1

Development Actions and the Rising Incidence of Flood and Windstorm Disasters

This paper serves as a bridge between the IEGreport Hazards of Nature, Risks to Development(2006) and two upcoming IEG evaluationreports, on the environment and on climatechange. Hazards of Nature reviewed the Bank’swork to prevent and respond to all naturaldisaster types over a 20-year period. Althoughthe review of 528 project experiences revealed anumber of trends, one unexpected insight wasthat Bank lending in response to tropical stormsand floods was increasing at a rate even higherthan the sharply rising pace for disastersgenerally. In response to a new and moreaccurate understanding of the risk levels thathobbled development gains in borrowercountries, IEG opted to devote additionalresources to further explore the threatpresented by these hazards under the broadertheme of natural disasters.

This Brief is partly based on visits to the field,including recent IEG project-level evaluationsand several background papers. This material issupplemented by a comprehensive desk reviewand an interactive database summarizing theachievements and challenges faced by recentdisaster-related projects and based on self- andindependent evaluation.

Although this Brief focuses on flooding andwindstorms—reflecting the seriousness of theirrapid increases—certain disaster-related statis-tics are presented in accordance with UN defini-tions (see box 1.1). Accordingly, some of theanalyses include other disaster types (but onlywhen so noted). Data from the Center forResearch on the Epidemiology of Disaster (fromits EM-DAT database) includes all intersectinghazard types listed in the UNISDR definition of

hydrometeorological disasters (see box 1.1).Vulnerability levels were determined using thefindings of the Natural Disaster Hotspots Study(World Bank 2005).

How Serious Is the Increase inDisasters?In the aggregate, the reported number of naturaldisasters worldwide has been rapidly increasing,from fewer than 100 in 1975 to more than 400 in2005. A glance at the 100-year record highlightsthe dramatic nature of the recent upsurge (seefigure 1.1).

The human cost of these disasters has beenstaggering. The number of people affected1 bynatural disasters each year nearly quadrupledfrom 1975–84 to 1996–2005 (see figure 1.2), and

Disaster: A serious disruption of the functioning of a community or asociety causing widespread human, material, economic, or environ-mental losses that exceed the ability of the affected community or so-ciety to cope using its own resources.

Hydrometeorological Disasters: Natural processes or phenomena ofatmospheric, hydrological, or oceanographic nature, which may causethe loss of life or injury, property damage, social and economic dis-ruption, or environmental degradation.

Hydrometeorological hazards include: floods, debris and mud floods;tropical cyclones, storm surges, thunder/hailstorms, rain and windstorms, blizzards and other severe storms; drought, desertification,wildland fires, temperature extremes, sand or dust storms; and per-mafrost and snow or ice avalanches. Hydrometeorological hazardscan be single, sequential, or combined in their origin and effects.

Source: UN 2006.

Box 1.1: UNISDR Definitions

the vast majority were in developing countries.In fact, 98 percent of the 211 million peoplekilled or affected by natural disasters each yearfrom 1991 to 20002 were from nations of low ormedium human development (InternationalFederation of Red Cross and Red CrescentSocieties 2001).

What Are the Major Causes?In part, the rise is related to population. Thelong-term disaster trend remained relativelystatic until the 1940s, when the incidence of

catastrophic events began to rise steadily. Duringthe same period, the world’s population grewfrom approximately 2.7 billion to about 6.5billion.3

Another cause is urbanization. As the populationgrew, it began to shift from rural areas to cities.4

In 1950, only one-third of the world’s peoplelived in urban areas. With more than half of theworld’s population now living in cities, urbanareas are the drivers of economic growth. In1950, New York was the only megacity—definedas a metropolitan area having a population ofover 10 million. In 2006, there were 25 suchcities, including 19 in developing countries.

Environmental fragility caused by changes inpopulation and land use over the past 50 yearshas greatly increased vulnerability, so that noweven small-scale events produce large disasters.Population growth has meant increased strainson the environment and resultant environmen-tal degradation. As people move from rural areasto more densely populated zones, “greenfield”sites become urbanized, disrupting watersheddynamics, and potentially aggravating flooding.And as people move to overcrowded cities andthe cities themselves generate additionalpopulation growth, the areas available foroccupation tend to be more dangerous thanthose occupied by the people that came earlier(Mellinger, Sachs, and Gallup 1999). Over-crowded and rapidly growing cities pose anincreasing risk to many of the people living inthem—but especially the poor.

Coastal areas are being used more intensively andaccount for 53 percent of the world’s GDP. Abouta quarter of the world’s population lives within100 kilometers of the coast, and many rural areasare vulnerable to tidal surges and swollen riversbringing runoff from higher elevations. And thecoasts are much more densely settled now thanthey were a few decades ago. Of the 25 megaci-ties, 14 are on the coast and 7 are within a fewhours’ drive. This concentration of settlementalong the coast is “setting us up for rapidlyincreasing human and economic losses fromhurricane disasters, especially in this era of

2

E VA L UAT I O N B R I E F 4

Figure 1.1: Number of Natural Disasters in All Countries

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

1900

–04

1910

–14

1920

–24

1930

–34

1940

–44

1950

–54

1960

–64

1970

–74

1980

–84

1990

–94

2000

–04

Num

ber o

f dis

aste

rs

Source: EM-DAT: The OFDA/CRED International Disaster Database, <www.em-dat.net > Université

Catholique de Louvain, Brussels, Belgium.

Figure 1.2: Billions Affected by Natural Disasters

0.6

1.8

2.3

0

0.5

1.0

1.5

2.0

2.5

1976–85 1986–95 1996–2005

Peop

le a

ffect

ed b

y di

sast

er (b

illon

s)

Source: EM-DAT: The OFDA/CRED International Disaster Database, <www.em-dat.net > Université

Catholique de Louvain, Brussels, Belgium.

heightened activity,” according to the latestscientific thinking (Emanuel 2006).

Developing Countries ExperienceDisproportionate Economic Impacts Living in dangerous zones, on marginal lands,and with precarious livelihoods, the developingworld’s poor are rarely insured against disaster-related damages. Global disaster databases5

reflect the increase and highlight the likelihoodof rising costs to national governments.

The economic costs of disasters are large. During1996–2005, disasters caused over $667 billion indirect material loss worldwide. Economic lossesdue to natural disasters are 20 times greater (as apercentage of GDP) in developing than indeveloped countries.6 This disproportionate effecthas many explanations. Lack of development itselfcontributes to disaster impacts, because the qualityof construction often is low and building codes,land registration processes, and other regulatorymechanisms are lacking, as well as becausenumerous other development priorities displaceattention to the risks of natural events.

Developing countries are especially hard hit, notonly because of direct damages, but also becauseof the indirect and secondary economic effects,such as disruptions in the flow of goods andservices following disaster.7 Another importanteconomic impact, which is quite difficult toquantify, is the extent to which the possibility ofanother disaster striking the same area may be adisincentive to investors—referred to by some asa “fear factor.” If businesses and investors areworried that a country is not prepared for thenext disaster (because the underlying risks havenot been reduced), the long-term impacts ofinvestor uncertainty can equal or surpass thecost of the disaster itself (Dercon 2006). Even thestability of an economy may be affected, ifinvestors worried about underlying conditionsdramatically reduce capital inflows.

Considering both the economic implications ofthe loss of productive assets and the secondaryand indirect costs that are not part of the totalspresented, true disaster losses are even higher

than those reported. Taken together, theaccumulating burden of human and economicloss from disaster throws into tumult thedevelopment plans of the regions and countriesaffected by disasters.

Which Disasters Are the Fastest Growing Problem?While natural disasters are increasing overall, asnoted above, two types—flooding and windstorms— are increasing much more rapidly thanthe others (figure 1-3).

Their number is increasing dramatically, with anannual average increase of at least 5 percent. Tosome degree the two types of events go hand inhand. Tropical storms can cause flooding, andflooding is frequently triggered by unusuallyheavy rains—which are not always from “named”storms. And not only are tropical storm disastersup; extreme weather events (that is, unusuallyheavy rainfalls not caused by cyclones orhurricanes)8 also are more frequent. Moreover,the damage caused by extreme weather events,flooding, and wind storms has also accelerated.

As a group, weather disasters—drought, extremetemperatures, floods, mudslides, wave/surges,and windstorms (commonly referred to ashydrometeorological events)—affect morepeople than all other disasters combined. During1972–2006, more than 5,250 million people wereaffected by hydrometeorological disasters,compared with about 11.5 million for all otherdisasters combined (earthquakes, insect infesta-tions, volcanoes, and wildfires).9 Storms andfloods alone account for about 67 percent of theabove number of individuals impacted, or 3,500million people.

The economic costs of these disasters are partic-ularly high when compared with other devastat-ing events, not only because of their frequency,but also because they often occur near the coast,where much of the population is concentrated(see figure 1.4). In addition, the rate of increasefor the economic damages caused by floods,hurricanes, cyclones, and typhoons has beenescalating. When a regression line is plotted to

D E V E L O P M E N T AC T I O N S A N D T H E R I S I N G I N C I D E N C E O F D I S A S T E R S

3

the annual amount of actual economic damage(current dollars), the percent increase of the lineis 10 percent. In constant dollars the increase is7.8 percent.

Development Actions Investments in development generate activitiesthat have a multiplicity of positive outputs andimpacts. But unless natural hazards (in this Brief,the risks of floods and windstorms areemphasized) are expressly taken into account,development investments can inadvertently raisevulnerability, sometimes dramatically. Box 1.2shows how a badly needed rural road alsocontributed to a rise in vulnerability.

Projects financed by the Bank naturally tend tofocus on zones where economic activity occursand more people live. They therefore tend to belocated along the coast—an area particularlyvulnerable to flooding and storms. The Bank’sintensive focus on the poor also means thatBank-financed infrastructure risks being increas-ingly located in fragile areas.

The StudyTo determine the vulnerability of Bank-financedprojects it was necessary to ascertain exactlywhere they are located. This Brief relies on anumber of innovative evaluation techniquesinvolving a mix of geospatial analysis, qualitativedata analysis, and database analysis. For instance,it employed GIS/ArcInfo in its analysis. Latitudeand longitude for all of the Bank-financed portprojects implemented since 1983 were obtainedwhere possible and activities were mapped usingArcInfo. The ports were located on a GIS map,and 100-kilometer-radius buffer zones wereestablished for each of the 300 ports. Thepercentage of vulnerable land within this radiuswas then calculated by overlaying hazard maps.This study deliberately piloted methods for thetwo follow-on studies on climate and environ-ment, especially the former. This sort of analysiswill be further developed in those upcomingstudies.

Qualitative data analysis (QDA) software (AtlasTi)enabled the team to analyze the entirety of

4


Figure 1.3: Flood and Wind Storm Disasters Are Increasing in Frequency

Disaster occurrence by type 1972–2005

0

20

40

60

80

100

120

140

160

180

200

1972 1976 1980 1984 1988 1992 1996 2000 2004

Num

ber o

f eve

nts

Flood Windstorm Earthquake

Drought Slides Wildfires

Volcano Pest infestation Wave/surge

Source: EM-DAT: The OFDA/CRED International Disaster Database <www.em-dat.net > Université Catholique de Louvain, Brussels, Belgium.


5

Figure 1.4: Economic Cost of Hydrometeorological Disasters Is Higher than That of All Other Disaster Types Combined

�20,000,000

0

20,000,000

40,000,000

60,000,000

80,000,000

100,000,000

120,000,000

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

Year

Econ

omic

cos

ts (

$US,

000

)

Hydrometeorological disastersAll other natural disasters*

Linear (all other natural disasters)Linear (hydrometeorological disasters)

Source: EM-DAT: The OFDA/CRED International Disaster Database <www.em-dat.net> Université Catholique de Louvain, Brussels, Belgium.

Note: This database reports large- and medium-scale disasters, not local, small-scale ones. *This category includes earthquake, insect infestation, volcanoes,

and wildfires. Hydrometeorological disasters include drought, extreme temperatures, floods, mudslides, wave/surges, and wind storms.

People have always been vulnerable to disaster, and no matterwhat is done to prevent disasters, they will still happen. How-ever, vulnerability is affected by development activities. Such ac-tivities may have desirable outcomes, yet may also increasevulnerability to disasters.

Unpaved roads contribute disproportionately to basin-widerunoff and stream sediment. According to Ziegler and others(2004), who studied the impact of rural roads in Pang Khum Ex-perimental Watershed (PKEW) in northern Thailand, many road sec-tions are constant sources of sediment and runoff during most rainevents. This happens because water begins flowing over land oncompacted earthen surfaces after small depths of rainfall, and theseflows go directly to nearby streams. Surface preparation processesperformed when these roads are maintained renew the supply ofeasily transportable surface sediment. The authors note that ero-sion of the road surface is accelerated in locations where slopes

are steep, overland flow distances are long, and/or vehicle usageis high. Furthermore, runoff typically exits from the road directlyinto the stream. Sediment delivery rate on the studied roads is morethan an order of magnitude higher than that on adjacent fields. Theresearch team concluded that unpaved roads appear to be of thesame order of importance as agricultural lands in contributingsediment to the stream network, despite occupying a fraction ofthe total surface area in the basin.

Burning the forest to clear land for agriculture is a practice thathas spread rapidly and has contributed to increasing runoff. Thephenomenon has made its way into the rainforest through theroad system, with close to 75 percent of the deforestation takingplace within 50 kilometers of a paved road. Often these fires ac-cidentally get out of control, destroying even more of the forest.As a result, nearly 60 million hectares have been cleared in the pasttwo decades.

Box 1.2: A Chain of Events, Beginning with a Road

almost 6,000 project documents related to theBank’s disaster operations. Key words wereflagged, and pertinent passages pulled forthorough analysis of discrete topics.

A portfolio review was conducted using Bankdocumentation and the database prepared for the2006 natural disaster study (Hazards of Nature,2006), which contains over 80 fields of informa-tion on 528 Bank-financed disaster responses.These responses were analyzed to identify whichactivities have been undertaken most often, alongwith project performance ratings, to determinewhere the Bank has been most successful as wellas where it needs to improve practice. Wherepracticable, the database was updated to includerecent developments.

The report team conducted an extensive reviewof the literature to capture a broad picture of thelatest information in the field, including athorough review of several scientific journals.The literature review focuses on weather eventsand their interactions with urban and ruralenvironmental degradation. Key policy issuesregarding urbanization, tools and indicators,current debates, and cutting-edge issues alsowere reviewed.

Notes1. The Red Cross and Red Crescent Societies define

“the affected” as “those who at least for a time

either lost their homes, their crops, their animals,their livelihoods, or their health, because of thedisaster.”

2. This is seven times the number of people killed oraffected by conflict.

3. Population Division of the Department ofEconomic and Social Affairs of the United NationsSecretariat, World Population Prospects: The 2004Revision and World Urbanization Prospects: The2005 Revision, http://esa.un.org/unup, 25October 2006.

4. Cities have absorbed almost two-thirds of theplanet’s growing population since 1950.

5. Global databases that show an increase in thedestructiveness of tropical storms are NatCat,maintained by Munich Reinsurance Company(Munich); Sigma, maintained by Swiss Reinsur-ance Company (Zürich); and EM-DAT, maintainedby the Centre for Research on the Epidemiology ofDisasters (CRED, Université Catholique deLouvain, Brussels).

6. Disaster Management Facility (DMF) Web site, TheWorld Bank, http://www.worldbank.org/dmf/

7. The convention is that indirect losses should notbe reflected in the economic cost figures, norshould the secondary effects of the event be takeninto account (such as the impact on the overalleconomy in the years following).

8. Not graphed because the relative frequency ofheavy rainfalls would alter the scale and hide themain point being made here.

9. EM-DAT: The OFDA/CRED International DisasterDatabase <www.em-dat.net >, Université Catho-lique de Louvain, Brussels, Belgium.

6


7

CHAPTER 2

Bank Lending for Flooding and Storms

Each Bank Region is affected differently bydisasters. Table 2.1 shows that flooding disastersare increasing in all borrower Regions, but the rateof increase is considerably smaller in one of them.Europe and North America are included forcomparison purposes. Tropical storm disasters areincreasing in Africa, Latin America, and the MiddleEast and North Africa. Drought is increasingeverywhere but in North America.

East Asia and the Pacific, Latin America and theCaribbean, and South Asia have the largestnumber of Bank-financed flood projects, and theEast Asia and the Pacific Region has the highestpercentage of its disaster lending related toflooding (see figure 2.1).

The Region hit hardest by tropical storms is LatinAmerica and the Caribbean, which accounted for51 percent of the 75 projects related to storms(see figure 2.2). Africa follows, with 23 percent ofthe Bank’s tropical storm projects. As a percent-age of total natural disaster projects in eachRegion, tropical storms accounted for the largestportion in Latin America and the Caribbean.1

Between 1984 and 2005, approved loans withsome flood-related activity totaled $23.5billion—almost 55 percent of the total for allprojects involving disaster. Figure 2.3 shows themakeup of the Bank’s flood and tropical stormportfolio, with comparisons to the rest of theBank’s natural disaster project portfolio.

Flooding The vast majority of floods occur in countries thatborrow from the World Bank (see figure 2.4).Developed countries have decades of invest-ments in flood and storm water control, as well asstrict land use planning, which help preventdisasters. Many developing countries are only justbeginning to provide themselves with suchprotections.

The Bank’s portfolio has generally kept pace withthe rising borrower demand occasioned by theupward trend of floods. Although the ratio ofBank projects to flood events appears to belower in the most recent period (since 2003), thisis more an accounting phenomenon than atrend: reallocations tend to take place in the later

Tropical Region Floods storms Drought Wildfire Earthquake Volcano Landslides

Africa + + +

East Asia/ Pacific + + + +

Europe + + + +

Latin America/Caribbean + + + + +

Middle East/North Africa + + +

North America + +

South Asia + + +Data source: CRED-EM DAT.

Note: Bold plus sign means trend since 1972 has increased at an annual average > 5 %.

Table 2.1: Where in the World Are Disasters Increasing?

years of a loan, and the most recent loans are notyet at that stage.

Of the 528 projects in the disaster portfolio, 243(46 percent) are related to floods.2 Not only isthe portfolio related to flooding sizeable, butalmost half of the projects (47 percent) areongoing. The average cost of flood projects—$96.5 million—is smaller than that ofearthquake, landslide, and tsunami disasterprojects, but as noted previously, when individ-ual loan amounts are added together, loanshaving to do with flooding receive the bulk ofBank disaster funding (see figure 2.5).

As disasters have become more costly, the averagecost of individual Bank-financed flood projects has

grown. The average flood project loan in 1984 wasfor $61 million, but in 2005 it was for $114 million,almost double. Reflecting the steep rate ofincrease in flood occurrences, the number ofprojects and the amount of Bank lending haveincreased. The number of hurricane and cycloneprojects has only increased slightly, however.

Figure 2.6 shows the increase in actual loanamounts approved by the World Bank for thesephenomena. The total amount of lending forfloods has increased substantially over the years,while the total lending amounts for droughts andtropical storms have stayed relatively constant.

The 243 projects that addressed floodsundertook 60 distinct activities (many projectsincluded multiple activities). Eight of the top 20activities in flood projects involved rehabilitationor restoration—of road infrastructure, floodcontrol structures, irrigation/drainage infrastruc-ture, urban and rural water systems, educationfacilities, health facilities, and urban water/sanita-tion infrastructure.

The emphasis on rehabilitation indicates thatmuch public infrastructure does not hold up toflooding. A failure to perform maintenance oninfrastructure, an entrenched problem, oftenleads to its premature deterioration. Disasterexperts agree that this issue requires attention.The 2004 Caribbean Regional Disaster Confer-ence “Managing Hazards in a Changing Environ-ment” concluded that governments’ investmentsin large-scale structures to reduce disaster vulner-ability have been seriously compromised byfailure to conduct and fund maintenance. Thisproblem is not confined to small island states. Forexample, many Bank-financed cyclone sheltersalong the Bay of Bengal are no longer usable forlack of maintenance. IEG missions to South Asianoted that breached, failed, and crumblingembankments were common. In another case,the effectiveness of Bank-financed flood controlinfrastructure protecting a major South Americancity (that had previously experienced catas-trophic flooding) was severely compromised bythe presence of junked automobiles and refuseblocking the watercourses.

8


Figure 2.1: Flood-Related Projects by Region:1984–2005

020406080

100120140160

EAP SAR MNA LAC ECA AFR

Region

Num

ber o

f pro

ject

s

Other disasters Floods

64%57%

54%

41%

39%

34%

Source: IEG data.

Note: EAP = East Asia and Pacific; SAR = South Asia; MNA = Middle East & North Africa; LAC = Latin

America & the Caribbean; ECA = Europe and Central Asia; AFR = Africa.

Figure 2.2: Tropical Storm–Related Projects by Region: 1984–2005

020406080

100120140160

LAC EAP AFR SAR ECA MNA

Region

Num

ber o

f pro

ject

s

Other disasters Tropical storms

30%

12.8%

12.7%

12%

00

Source: IEG data.

Note: See figure 2.1.


9

Figure 2.3: Total Lending Amount (in US$ millions) by Disaster Type: 1984–2005

Figure 2.4: Global Distribution of Flood Risk—Economic Loss as a Proportion of GDP Density

15,397.5

1,7862,517

4,825

50

8,8678,100

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

Floodonly

Tropicalstormonly

Flood andtropicalstorm

Flood andother

Tropicalstorm

and other

Landslide, stormsurge, fire,

anddrought(other

meteorologicaldisasters)

Earthquakeand volcano

(non-meteorological

disasters)

US$

mill

ions

Floods and tropical storms

Source: IEG data.

Flood hazard deciles1st–4th 5th–7th 8th–10th

Source: World Bank 2005.

Tropical StormsTropical storms cause not only flooding but alsoextensive wind damage. Since the 1970s, cyclones,hurricanes, and other tropical storms have beenincreasing in frequency and destructiveness. Withthe increasing severity of storm events, newcountries are falling victim. Brazil suffered its firsthurricane ever in March 2004: Hurricane Catarina(not to be confused with Katrina) killed 3 people,injured 38, and rendered 2,000 homeless.

Figure 2.7 shows the number of major tropicalstorms in countries that borrow from the WorldBank and in those that do not. Part I countriesaccount for a larger share of events (compared

with flooding), although Part II countries stillpredominate each annual tally. Some areasparticularly vulnerable to tropical stormsinclude the Bay of Bengal, East Asia, and theCaribbean.

Storms are a special challenge for small islandstates, which have extensive coastlines, relianceon trade, and economies based on tourism.Since storm impacts are worse at the shore,where tourism investments are concentrated,import/export infrastructure tends to be located,and most people live, they can paralyze activitiesfor extended periods. Small island nations can—and often do—lose multiples of their GDP to

1 0


Figure 2.5: Floods Globally and the Bank Response

020406080

100120140160180200

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

Num

ber o

f flo

od e

vent

s

0

5

10

15

20

25

30

35

Num

ber o

f Ban

k p

roje

cts

Client country floods Global + client Bank flood projects

Source: IEG data.

Note: Total number of floods globally is shown by adding the client and non-client bars.

Figure 2.6: Flood Project Lending Is Rising

0

500

1,000

1,500

2,000

2,500

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

Am

ount

in U

S$ m

illio

n

Flood Tropical storm Drought

flood

droughttropical storm

Data Source: EM-DAT: The OFDA/CRED International Disaster Database < www.em-dat.net> Université Catholique de Louvain, Brussels, Belgium.

natural disasters: Grenada lost 200 percent of itsGDP to Hurricane Ivan in 2004.

World Bank lending for tropical storms isnoticeably cyclical. Over the past 20 years, thenumber of storm-related projects approvedannually has ranged from one to nine. Butother than an upward trend over time, no clearpattern is otherwise discernible. This isbecause the number of tropical storms that willstrike land is determined by sea temperatures,wind patterns, and other factors. The numberof storms thus oscillates considerably on anannual basis, with a bad storm year producingnearly five times as many tropical storms as thecalmest years in some zones. Bank funding fortropical storm projects3 has been flat over theperiod (see figure 2.6). In total, 76 projectswere related to tropical storms: 20 are ongoing(26 percent) and 56 have been completed (74percent).4

Tropical storms did not receive a large portion ofBank disaster-related funding in comparison withother disaster types, such as floods (see figure2.6). In part this is because the severity of individ-ual storms varies, and they sometimes hit coastalareas where there is no concentration of invest-ments. Between 1984 and 2005, the Banksupported tropical storm projects with totallending of $4.6 billion, which represented almost

11 percent of the total investments in naturaldisaster projects.

Tropical storm projects have used a unique basketof activities, and the activity mix is significantlydifferent from that of flood projects. Rehabilita-tion of roads is still the most frequent activity, butstudies and research take place much morefrequently (third most numerous activity, com-pared with thirteenth for flood activities). Earlywarning and public awareness are not even in thetop 20 list of tropical storm activities, nor areengineering design and project management, allof which are prominent in flood projects.Conversely, restoring transport facilities andbalance of payment support appear frequently intropical storm projects and not in flood projects.

Notes1. Since the 1970s, although droughts have been

increasing slightly in frequency, the number of Bank-funded drought projects has not increased. This ispresumably because agricultural projects in droughtareas now routinely promote drought-resistantvarieties, more sustainable use of water, and moreappropriate crops. Of the 528 projects in the IEGdisaster portfolio, 107 included drought activities.Of those, about two-thirds have been completed.The number of drought projects has held steady atan annual average of about five since 1984.

2. Because a project may respond to several differentdisaster events (for example, floods and


1 1

Figure 2.7: Number of Tropical Storm Disaster Projects by Year: 1984–2005

0

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Client countries Non-client countries Bank tropical storm projects

Data Source: IEG and OFDA/CRED EM-DAT.

Note: Total number of floods globally is shown by adding the client and non-client bars.

landslides), adding the percentages of projectsdealing with each different type will lead to a sumgreater than 100 percent.

3. Tropical storm projects, as with all the Bank’sdisaster-specific projects, include projects having

any activity related to major tropical stormdisasters (hurricanes, cyclones, and typhoons).

4. This number includes projects having any activityrelated to major tropical storm disasters(hurricanes, cyclones, and typhoons).

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1 3

CHAPTER 3

Development Investments at Risk to Flooding and Storms

A rough estimate of potential flooding and stormimpacts on the Bank’s ongoing portfolio wasderived by identifying the Bank sectors that tendto be the most affected and determining theirexposure.1 To estimate the percentage of Bankinvestments at risk in these sectors, the loanamounts of the active projects were multipliedby the percentage of GDP at risk for floods andtropical storms (numbers developed as part ofthe Hotspots study [World Bank 2005], whichprovides estimates of GDP at risk by disastertypes for each country). Table 3.1 shows thenumber of countries that are considered to havesome measure of risk to floods and storms. Sincesome countries are at risk of both, there isoverlap. Of the sectors where investments arelikely to sustain damage, the percentage of riskapplicable to GDP for the country was applied tothe sector portfolio. The amount of lending atrisk is the product of portfolio percentage at riskand loan amounts (the country breakdown ofrisk data by disaster type is still embargoed, andis therefore not included in this Brief).

Clearly, the estimates derived from this exerciseargue strongly that disaster vulnerability warrantsserious consideration on financial groundsalone—if Bank investments are located in amanner that mirrors the distribution of invest-ments generally, 60 percent of Bank investmentsin infrastructure, rural development, andenvironment are at risk to flooding, and 23percent to tropical storms.2

When comparing the at-risk portfolios to theBank’s entire active lending portfolio, projects atrisk to floods represent 38 percent of currentBank lending, and projects at risk to tropicalstorms represent 8 percent. And both disastertypes are on the rise.

The study team analyzed two Bank activities indepth, road and port-building, because these arethe most common activities in Bank-financedprojects following disaster events (30 percentacross all disaster types and 45 percent of allactivities in response to floods and tropicalstorms).

Roads Are Highly Vulnerable to DisastersAs global and regional trade has intensified,societies have become much more dependenton services and infrastructure that facilitates theexchange of goods. Roads are unquestionablymajor “lifelines,” in this sense, serving bothurban and rural areas. In the event of a majordisaster, roads are crucial in efforts to distributeemergency relief and to restore the localeconomy. A failure of these links following anatural disaster can have considerableconsequences, even for people in areas notdirectly affected.

Failures have been common (see figure 3.1).Road construction and rehabilitation are themost common Bank response to floods andtropical storms. Looking only at completed floodprojects with Bank involvement, 42 percentrehabilitated roads (just 2 percent constructedonly new roads). A similar pattern prevails for

Number of borrowers Percent of at risk, with active vulnerable Amount of

portfolios in sector Bank lending vulnerable portfolios vulnerable

sectors at risk (US$ billions)

Floods 84 60 36.0

Tropical storms 28 23 7.3Source: IEG and World Bank data.

Table 3.1: Bank Investments at Risk to Floods andStorms

tropical storm projects—47 percent rehabili-tated roads and none built only new roads.

Honduras provides a dramatic example of repeti-tive road failure in the face of storms. The WorldBank has been helping Honduras to build itshighway system since 1955, when it wasestimated to have 2,500 kilometers of roads. Inthe course of seven transportation projects, theBank financed construction of 1,270 kilometersof highways and feeder roads. While the Bank wastrying to help improve the highway system,Hurricane Fifi (1974) destroyed 60 percent of allthe roads in the country. After Hurricane Gert(1993), a relatively small event, roads had to berehabilitated because of mudslides (no percent-age data were found for road damage). By 1998,there were approximately 10,000 kilometers ofroads in the country. Hurricane Mitch (1998)destroyed 6,000 kilometers of the better roads(60 percent)—almost five times what the Bankhad helped to build. In addition, more than 163 bridges were damaged or destroyed.Estimates of the damage to roads from Mitchwere on the order of $454 million (MünchenerRückversicherungs-Gesellschaft 1975).

In some geographic areas the construction ofroads exacerbates the conditions that causefloods. When a road is built in a forested area,deforestation and erosion are not far behind(Alves 2002) (see box 1.2). Large-scale pavingsignificantly reduces infiltration, and naturalstorage of groundwater is reduced by improveddrainage (which, by definition, removes water to

another area). Also, streams are often constrictedby roads. Bridges may constrict the flow of water,especially when designers are unaware of peakrainy season flows, and they can act asunintended dams if debris jams their openings.The 2007 IEG transport study, A Decade of Actionin Transport, identified 65 Bank-financedprojects that constructed major (not rural) roads.Of those, only 14 (22 percent) constructed new(greenfield) roads, while the rest concentratedon rehabilitation and upgrading. The study citesflash floods and slope instability as threats to roadsustainability, and notes that “having to rehabili-tate paved roads too frequently because ofneglect could conservatively be more than threetimes as expensive for the road authorities (basedon undiscounted costs) as maintaining them on aregular basis.” Since disaster-related problemsgenerally also involve flash flooding and slopestability, providing adequate drainage, sufficientlydimensioned culverts, and designing roadalignments to provide the maximum protectionand stability possible pay significant dividendseven when they double road cost.

Roads can act as protective embankments andaid in mitigating the effects of flooding. Withgood local knowledge, road constructionprojects may raise roads above flood level. Whilethis practice has saved many lives—Bangladeshis a notable example—adequate consideration isnot always given to the number and size ofopenings necessary for local drainage ortributary inflow. In such cases the road can artifi-cially raise water levels upstream and causeadditional flood damage. Roads can also act aslevees to channel runoff away from fragile landsand into established watercourses. When theyare parallel to a river or stream, however, thewater level upstream can increase, and in theabsence of careful hydraulic study, result inadditional flood damages there.

An example of how poorly designed road systemscan be modified to take disaster and the environ-ment more into account is provided by the 1994Paraguay Natural Resource Management Project.The project’s overall strategy was to use the roadnetwork to support watershed management

1 4


Figure 3.1: Transportation Infrastructure DominatesBank Response to Floods and Tropical Storms

45%42%

31% 30% 29%

11% 10%

0

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Floodcontrol

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sewerage

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s

Source: IEG data.

plans designed to achieve sustainable agricultureand the conservation of natural resources. Longbefore the project began, forest had been clearedto increase the amount of land under cultivation,and a network of rural roads had been con-structed. But the forest clearing had paid littleattention to appropriate land use, and led to soildegradation, erosion, and runoff. In many placesthe road network dumped water into tilled fields,creating gullies. But while the roads contributedto soil erosion in some areas, they were subject toit in others: large stretches of road were oftenflooded and certain sections regularly washedaway. The project realigned, rebuilt, and providedfor the continuing maintenance of the roadnetwork. Only selected roads were abandoned orclosed, but in those cases trees were planted todefinitively prevent further use. As a result ofimproved agricultural practices and road rehabil-itation, the need for road maintenance was signif-icantly reduced. In effect, road maintenance costsdecreased by $540/km/year, and more roadsbecame passable year round, even followingmajor storms.

Lending for Ports Is at High Risk Port infrastructure is often vulnerable to naturaldisasters such as tropical storms (both fromstorm surge and flooding) and earthquakes.Between 1983 and 2006, the Bank lent $30,508million for the infrastructure or administrationof about 399 ports. The study attempted toevaluate the vulnerability of Bank lending forports—located at sea level, they are at leastsomewhat exposed to storms and abnormallyhigh tides. The analysis only covers 307 of theports because the documentation in Bankreports for the rest of the projects was notdetailed enough to permit the clear identifica-tion of the latitude and longitude of each port.3

Figure 3.2 shows the distribution of port projectsby region (IEG has pinpointed project locationson Google Earth).

According to data presented in the NaturalDisaster Hotspots Study (World Bank 2005), 52percent of the 307 ports were in areas with highrisk from flood, 34 percent in areas at high riskfor earthquakes, and 25 percent in areas at high

risk from tropical storms. Altogether, 70 percentof the 307 ports, representing 77 percent of theBank’s port lending, were at high risk from atleast one of the three hazards (floods,earthquakes, or cyclones). Even more alarming,40 percent of the ports, representing over $10.5billion, or 41 percent of the Bank’s port lending,were located in the top tenth percentile for riskfrom one of the hazards (see table 3. 2).

Another risk largely missing from projectdocuments is that of higher mean high tides. TheBank’s lending for ports may be threatened notonly by stronger storms, but also by globalwarming and rising sea levels. In only two portprojects were sea-level rise and climate changementioned as a threat. In all cases, as far as can


1 5

Figure 3.2: Port Projects by Region

020406080

100120140160

Africa LatinAmericaand the

Caribbean

East Asiaand

Pacific

MiddleEast and

NorthAfrica

Europeand

CentralAsia

SouthAsia

Num

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sRegion

Source: IEG data.

Ports Dollar investment LOW: Ports at low risk from all three hazards 62 ports (20%) $3,822M (15%)MEDIUM: ports at medium risk from at least one of the hazards 29 ports (9%) $2,417M (9%)HIGH: ports at high risk from at least one hazard 215 ports (70%) $19,908M (77%)TOP 10th PECENTILE: ports for which risk of at least one hazard is in the top 10th percentile. 123 ports (40%) $10,501M (41%)

Table 3.2: Analysis by Highest Risk

be determined, no action was taken to adaptports to rising risk levels.

The bulk of the 399 port projects approved since1983 have supported better administration ofport projects. This includes institutionaldevelopment or privatization of ports aimed toincrease efficiency of cargo handling (183projects). New regulations and pricing wereintroduced in this context. An efficiency increase,an important objective in 199 projects, was to beachieved not only through privatization andbetter regulations, but also by improving thelinks between ports and the road or railwaynetworks (138 projects). Studies were under-taken in 107 projects in order to monitor andimprove efficiency. Projects in 99 countries im-proved links for exports such as log transport, aswell as coal, metals, and agricultural products.

But not all port projects were geared towardmajor export ports. The Bank also supported

secondary and tertiary ports as well as smallfishing ports. Port improvements are heavilyfocused on the Africa Region (see figure 3.2).

Notes1. This includes infrastructure (global infrastructure,

energy and mining, transport, urban development,and water supply and sanitation), rural develop-ment, and environment.

2. An estimate of flooding and storm impact on theBank’s ongoing portfolio was derived by analyzingthe Bank sectors that are the most affected bythem. Some parts of other sectoral portfolios thatcould also be affected were not included as theywere relatively small and difficult to accuratelyidentify. To estimate the percent of Bank funding atrisk in these sectors, the loan amounts of the activeprojects were multiplied by the percent GDP at riskfor floods and tropical storms. The Hotspots studyprovided the information on the percent of GDP atrisk to flooding and tropical storms, by country.

3. The analysis represents $25,904 million, or 85percent of the Bank’s investment in ports.

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1 7

CHAPTER 4

Engineering and Planning Issues inManaging Watersheds for Flooding and Storms

Reducing vulnerability to disasters caused bystorms and flooding is largely a matter ofwatershed management, which has engineeringand planning as well as ecological aspects. Theengineering aspects involve adaptation to thelikely hazards. Planning involves land use and theplacement of infrastructure to reduce exposure.The engineering and planning issues related towatershed management are slightly different inareas of high population density than in thosewith lower population density. In high-densityareas, issues relate mainly to controlling the flowand location of water. In lower-density areas, theengineering and planning issues often relate tolarge infrastructure intended to control drainageand provide irrigation.

There is strong interplay between the urban andrural areas that can increase vulnerability todisasters related to storms and flooding. This canbe seen in the type of areas in which floodprojects are implemented: 42 percent take placein rural areas, 25 percent in urban areas, and 33percent span both urban and rural. Changes inland use and water courses in rural areas canhave catastrophic and unforeseen consequencesfor major urban areas. Conversely, demand forurban land can lead to the loss of productiveagricultural plains and encourage deforestationon nearby hillsides, which in turn causes erosion,crop loss, and repetitive flooding. Runoff reducesthe usable lifespan of expensive reservoirs.

Watersheds may be urbanized, but whether theyare or not, they are can be damaged whenforests, agriculture, industry, and drainage arenot properly managed. Poverty can exacerbatethe situation. Poor residents, out of financialnecessity, often deplete the natural resources in

and around the city in their daily quest for food,fuel, and shelter. Metropolitan developmentefforts can diminish either the rural or the urbanresource base, or both, thereby contributing to creeping environmental degradation anddisaster vulnerability.

Infrastructure can be adapted to hazards towithstand severe conditions with minimaldamage. There is a generally accepted rule that a10–15 percent increase in cost can usually make abuilding safe from all but the most extremeearthquakes and storms. Flooding involves differ-ent and even more complex dynamics. At somepoint the trade-off between cost and protectionbecomes onerous, however. Hardening structuresso that they are protected from the 500-year or1,000-year storm is unaffordable, especially whencompared with the cost of insurance.

A key issue in project and policy design is thechoice between adaptation to risk and insurance.While it is possible to ”gold-plate” infrastructureto make it impervious to storms and flooding,choosing whether to insure or adapt is, amongother things, a function of expected storm/floodfrequency, construction cost, maintenance costs,societal risk tolerance, and access to funds forreconstruction. The choice is never obvious,though roads tend not to be insured, and itbecomes much more difficult given that histori-cal storm frequency records provide poorguidance for the future, given climate change.

Effects of Rapid, Unplanned UrbanizationAvoiding catastrophic events in densely settledareas is critical: high population concentrationsalmost inevitably result in high death tolls, andhigh property values result in high losses.

High levels of urban vulnerability to disaster canbe blamed on planning failures. Ineffective landuse planning coupled with rapid urban growthand a lack of suitable and affordable housingmeans that poor families often end up indensely packed, poorly serviced, and danger-ously located neighborhoods—slums. One inthree urban dwellers lives in a slum—and thatnumber will double in the coming 30 years ifnothing is done to manage urban growth andmigration.

Another part of rapid urban conversion involvesroad building, which brings air pollution(pavement, being for cars and trucks,contributes to air pollution and global climatechange); siting and planning problems such asbuilding on floodplains or on unstable slopesbecome an issue; and weakening of coastaldefenses and the hardening of the coastline,including the construction of sea walls andembankments, contribute to increased urbanvulnerability to disasters.

Cities also suffer from over-asphalting, a lack ofgreen spaces, and a lack of investments ininfrastructure, which can contribute to a host ofissues that make an urban area more vulnerableto disaster— altered runoff patterns, less absorp-tion, pollution, subsidence, and land scouring.Few cities have preserved the forests andwatersheds once found within their boundaries,and the vast paved areas impede the naturalrecharge of aquifers (see box 4.1). Solid andliquid wastes and seawater have polluted manysources of freshwater that can no longer be

economically reclaimed. Few cities, if any, stillhave tree-lined harbors, clean rivers and lakes,sufficient subterranean water, and protectiveground cover. Because of environmentallydisastrous urban development, any discussion ofthe vulnerability of cities to unusual weatherevents must consider restoring the naturalresources essential to the survival of the cities,but which are now located too far from cityboundaries to provide any protection.

Storm Drainage in High-Density AreasIn many developing countries, inadequateinfrastructure or poor maintenance of existinginfrastructure can lessen urban resistance tonatural hazards, and even create additionaldangers. In the absence of a functioning sanitarysewer system, human waste often turns aflooded area into an open breeding ground fordisease following heavy rains. To give somedimension to this problem, inappropriate designand siting of housing, roads, bridges, andindustry (in Tegucigalpa and elsewhere) wereestimated to account for 50–75 percent of theeconomic losses associated with HurricaneMitch in Central America.1

Likewise, constructing infrastructure withoutcomprehensive planning for service provisioncan result in the loss of hard-won developmentgains. Where storm drains are built before refusepickup has been established, sewers becomeblocked with trash, often requiring rehabilitationas expensive as the construction of a new system.

Comprehensive urban development strategiesthat include building codes, land use planning,and zoning will become increasingly critical todetermining the best use of vulnerable areas.Local governments will need to play an increasingrole in planning processes. Inattention towatershed dynamics can lead to urbanization ofslopes without adequately planning for thevolume of runoff to be managed during heavyrainfalls. Given the size and unplanned growth ofmetropolitan areas, this can drastically alterrunoff patterns and, by impairing rainfall infiltra-tion, increase the speed of water runoff andrelated damage.

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Rapid expansion of metropolitan areas, and the impervious cover thataccompanies such expansion, impedes rainwater from rechargingaquifers and contributes to fast and polluted runoff, which in turn flowsdirectly into streams and rivers. Under natural conditions, 15 to 20 per-cent of the volume of rainfall contributes to direct runoff, but over 80percent does in urban areas. The volume and rate of runoff have beenshown to increase dramatically when impervious cover exceeds 10 to15 percent of the total surface area of any watershed.

Box 4.1: Runoff Increases Dramatically in Cities

If disaster is taken into account in settlementdesign, hazard-resistant infrastructure can makedangerous areas safe, and hazard-resistantbuilding techniques can be incorporated intohousing programs to protect lives, property, andemployment.

The Bank has done a lot to reduce the runoff problemThe study team analyzed all Bank projects to seewhat the experience has been in providing loansto governments for storm drains. Since 1983, 171Bank-financed projects supported the construc-tion and/or maintenance of storm drains. Smallto medium-size cities have been the mostcommon beneficiaries.

There are complementary areas that may warrantincreased attention, however. While storm drainscan help lessen urban flooding problems, withseemingly minor imperfections in conceptionand design they end up exacerbating them.Three main issues were found in analyzingproject documents (see box 4.2).

Bank-financed urbanizations would benefit by

balancing structural and nonstructural measures,and especially by taking more account of theneed for green spaces and trees, to improve theabsorption capacity of the soil. Urban utilitysystems and “lifeline” systems, such as water,electricity, key transport links, and communica-tions can be constructed (especially forhospitals) with local hazard risks in mind so thatkey facilities will be functional and able to aidvictims in the aftermath of a disaster.

Finally, the rapid expansion and siting of slums andsquatter settlements where vulnerability is highesthas increased the cost and magnitude of urbandisasters. In fact, the bulk of the investment thatthe poor make in their own settlements directlycontributes to urban vulnerability. They buildwhere others do not want to—on steep hillsides,near or on landfill sites, at the river’s edge, in thewetlands, and in similarly marginal areas. Incountries where the poor have moved into areasof water runoff, flash flooding is a major problem.IEG missions have observed that in Brazil,squatters’ homes cling to Rio’s steep hillsides; inBangladesh, with nowhere else to go, the poorbuild their houses over the sea on dangerous


1 9

Storm drains consist of canals or pipes above or below ground thattransport excess water from storms and heavy rains into a receivingwater body (for example, rivers, lakes, or the sea). Their functionis to prevent local flooding and provide safety to surroundinghouses and infrastructure, generally increasing the land value ofsettlements. While storm drainage provides an important servicein the context of slum upgrading and flood protection, it may alsoexacerbate flooding in certain circumstances. Several IEG ProjectPerformance Assessment Reports (PPARs) reveal the following:

Slope stabilization necessary to prevent silt build-up in stormdrains. Storm drainage is easily put out of commission by mudand sand in storm runoff that fills and eventually blocks thepipes. Lack of maintenance allows routine rainfalls to destroy theinfrastructure investment. The sequencing of service provisionis also important. Solid waste can clog drainage whether silt ispresent or not, and unless waste collection services are providedbefore storm drainage, some provision for keeping garbage outof the system is essential. Of course, storm drains need regular

maintenance and institutions need to be in place to maintain func-tioning storm drains.

Poor households may opt to illegally use storm drains as san-itary sewers to avoid having to pay sewerage connection fees.This poses health risks, since sewage reaches rivers untreated.It poses even higher health risks during floods, when untreatedsewage runs through the streets and sets houses under water.

Design errors can undermine the functioning of storm drains.If storm drains are designed too small, or with the wrong heightand slope, storm water may not reach the river. In St. Lucia, forexample, contaminated water accumulated a few hundred me-ters from the outlet of the canal, resulting in a garbage trap thatproduced odors and encouraged mosquitoes to proliferate afew steps from the main street. Similar problems plagued aBank-financed system in Sfax, Tunisia. In Turkey, one down-town area faced flooding from an under-dimensioned stormwater recipient with hardened concrete banks.

Box 4.2: Storm Drainage Can Exacerbate Flooding If Care Is Not Taken

floodplains; in the Philippines, squatters haveeven built precarious houses within and on top oflarge storm drainage culverts.

Drainage and Irrigation in Low-Density AreasUnsustainable agricultural practices are increas-ing vulnerability in low-density areas. An IEGreview (IEG 2002) found that the primary focusof the majority of agriculturally focused waterresource projects is on improving in-field soiland water conservation, not on managingwatersheds as a whole. Projects often deal withreducing siltation, less often with pollutionreduction, and even less frequently (about 5percent) with integrated water management.Sometimes, the construction of infrastructuremay encourage degradation (see box 4.3).

One major difficulty is in linking water develop-ment to the Country Assistance Strategy (CAS)agenda. Water sector interventions in CASs aregenerally subsumed under broader developmentgoals. The explicit valuation of water andrecognition of its role in environmental mainte-nance is fraught with difficulty, leaving itundervalued and unrecognized until there areproblems. The IEG water resources study,Bridging Troubled Waters, tied decisive action inthis area with natural and manmade disasters:“water issues tend to attract political attention

mainly for extreme events—Bangladesh’s FloodAction Plan, El Niño Emergency Loans for Peruand Bolivia, or the Sudan and ZimbabweDrought Recovery Credits—or when things gowrong—arsenic in Bangladesh’s groundwaterand India’s Narmada Dam controversy.”

Flood Control Infrastructure and NaturalDrainage Patterns Rivers and floodplains have long attracted humansettlement, agricultural activity, and commerce.These and other human activities have altered thenatural flow of rivers. Sometimes majoralterations are the result of deliberate river-changing actions. An “unimproved” river flowsthrough plains in large s-loops. Seasonally itswells and inundates the adjacent plains withnutrient-rich sediments. To reduce flooding andto make rivers navigable, river engineers andplanners often channelize the flows. They widenand deepen rivers and cut the rivers’ loops(meanders) to shorten the time water and shipstake to reach the ocean or other bodies of water.2

Vegetation is also removed from the rivers’ edge,and floodplains are deforested, drained, and inparts paved over. These changes can reducewater retention capacity, increase water speed,and make rivers crest at higher levels, since all thewater reaches the river at the same time.

Embankments consist of barriers along the riverthat separate the river from its floodplain.Others protect low-lying coasts. Embankmentshave enabled people to settle in floodplains,construct houses and infrastructure, and toplant crops on the nutrient-rich soils. Whilethese structures protect people under normalweather conditions, they create a false impres-sion of security. Unusually high water,constrained as it passes by the embankmentsand a much smaller floodplain, can no longerfind the space as it travels along a river todeposit its extra water and sediments. Peakflows from heavy rain and snowmelt canovertop or even breach the embankments,creating damage in the floodplain. Once an areais flooded, standing water is trapped andseparated from the river so that it is unable torecede. Therefore, embankments can interfere

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In St. Lucia, only about 6 percent of all available land is considered primefor agriculture. IEG field visits found that, increasingly, farmers have beenclearing forests to bring more land under cultivation, moving in theprocess to steeper, higher land. The government has constructedfeeder roads to service these remote areas. This, in turn, encouragedfurther cultivation in adjacent areas and removed the vegetative coverfrom the country’s most steeply sloping areas. Poor farmers have everyincentive to continue degrading the island’s steep hillside environmentby clearing forests for agriculture, putting the more productive lowlandsat risk, while they have no incentives to invest resources or efforts inenvironmental protections.

Source: IEG 2005a.

Box 4.3: The Construction of Infrastructure Can Speed Degradation

with natural drainage patterns, exacerbatingflooding (see box 4.4).3

About 31 percent of activities in Bank-financedprojects that respond to flooding build floodcontrol structures—both preventative andcurative. Top Bank borrowers for floods borrowrepeatedly, with some borrowing over 20 timesfor flooding issues.

A first-order cause for concern is the resiliency offlood control investments. They regularly suffersignificant damage from the very type of disasterthey are designed to confront—in the Bank-financed work, 23 percent of projects shared thisfate (see figure 4.1). The damage almost alwayswas reparable and did not lead to the total loss ofthe structures in question.4

The Bank’s experience with flood controlinfrastructure shows that, at least in cases wheregovernments have no option but to self-insure,the importance of disaster resiliency needs to bestressed more strongly by sector leaders. Ofcourse, no flood control infrastructure will resistwhen ongoing stakeholder activities in itswatershed aggravate the problem the floodcontrol structures were designed to address.

Adapted, sustainable, and integrated manage-ment of natural resources, including reforesta-tion schemes (particularly those that stabilizeembankments), proper land use, and goodmanagement of rivers and coastal areas willincrease the resilience of flood infrastructure todisasters, and, by extension, better protect thecommunities they are intended to serve bymaintaining conditions as they were or, better,by reversing the prevalent types and trends ofenvironmental degradation.


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Bangladesh contains the world’s largest delta, complete with ahighly complex system of over 700 rivers, stretching over 24,000kilometers and covering about 7 percent of the country’s surface.The Ganges, Brahmaputra, and Meghna Rivers all flow intoBangladesh, and out to the Bay of Bengal through one main out-let, the Lower Meghna (the world’s third-largest river by volume).These rivers have a combined catchment area of 1,758,000square kilometers. In other words, Bangladesh is dealing withall of the water collected in an area that is more than 12 timesthe size of the country. It funnels nearly all the runoff of fivecountries—itself, Bhutan, China, India, and Nepal.

To complicate matters, 95 percent of the total annual water in-flow (844,000 million cubic meters) enters the country between Mayand October. Rainfall in Bangladesh contributes 187,000 millioncubic meters to this during the same time period.

The Bangladeshi government opted to use infrastructure-

based solutions, including embankments, and compartmentalizedland within the embankments, to provide a controlled environ-ment for social and economic development. The government hasbuilt over 5,700 kilometers of embankments (over 3,400 kilometersin coastal areas), more than 1,700 flood control/regulating struc-tures, and over 4,300 kilometers of drainage canals over the pastthree decades.

Notwithstanding, flooding has increased over this time. Majorfloods (covering more than 30 percent of the land area) all occurredafter 1974—in 1974, 1987, 1988, 1998, and 2004. That is a rate of oneevery six years. Land area affected has increased as well, from 35percent in 1974 to 60 to 70 percent in 1998 and 2004. This increase,along with a sharp rise in population, has created a situation inwhich flooding is more likely to result in disaster. Increasing at-tention to environmental restoration needs to supplement the con-struction of any new infrastructure.

Box 4.4: Bangladesh Focusing on Infrastructure-Based Approach to Flooding

Figure 4.1: Flood Control Infrastructure Experiences More Flood Damage than Other Flood-Related Infrastructure

0

40

80

120

160

Floodcontrol

Watersupply

Roads/transport

Housing Agri-culture

Equip-ment

EnergyNum

ber o

f act

iviti

es in

resp

onse

to fl

oods

Activities negatively impacted by disaster during implementationActivities completed

Source: IEG data.

Notes1. Retrieved from: http://www.iadb.org/regions/re2/

consultative_group/groups/ecology_workshop_1.ht2. The Rhine River is one example how channeliza-

tion contributes to increased flooding. “As a resultof channelization projects on the Rhine River, theriver was shortened in the braided section by 14percent and in the meander zone by 37 percent.The loss of 130 km2 of inundation through thedamming up of the Rhine has caused a rise of theextreme flood discharge as well as an increase inflow velocity. Before 1955, the flood peak took aperiod of 65 hours from Basel to Karlsruhe; sincethe end of Rhine development in 1977, it takesonly 30 hours” (Hunt 2004, p. 141).

3. Comprehensive data on the causes and impacts of

flooding are scarce in developing countries. Theamount of river channelization that occurs or themeasurements of land subsidence are oftenanecdotal. The data on how much coastal hardeningis occurring on any stretch of coastline or along riversin developing countries is similarly limited. This issurprising, given the number of people affected byflooding and the amount of damage it causes.

4. In this regard, however, their track record was nota great deal worse than those of many othercomparable activities. Additional research wouldbe required to understand how significant aproblem is involved: this figure only includesdamage that occurred during implementation,before the loans closed, and performance over themedium term has not yet been analyzed.

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CHAPTER 5

Ecological Issues in Managing Watersheds for Flooding and Storms

Floods are a natural and beneficial part of theecosystem; they recharge aquifers and invigoratetopsoil. Flooding becomes disastrous whenmore and more people are at risk because theylive and work in dangerous areas and when theiractivities interfere with the working of an ecosys-tem (construction on wetlands, altered watercourses). When precipitation patterns changeand when development of an area leads tounsustainable ground and surface water extrac-tion, water scarcity occurs. Infrastructure invest-ments and location of populations, dependingon how they are planned, can both set the stagefor major losses.

Scientists have found that the risk of large floodswith discharges exceeding those formerlyconsidered to be 100-year-level events frombasins larger than 200,000 km2 (hereafter greatfloods) increased substantially during the twenti-eth century and predict that this trend willincrease with rising greenhouse gas emissionsand associated global warming.1 Poorly con-ceived development investments can exacerbateseveral types of risk by having an adverse impacton a watershed or otherwise causing unintendedincreases in overall vulnerability. Some activitiesthat the Bank engages in can have mixed resultsregarding disaster vulnerability.

Land Use Issues—Deforestation,Desertification, UnsustainableAgriculture, and Water ExtractionToo much and too little water are related, butequally problematic. An early effect of climatechange will be potable water shortages in dryareas—a critical issue for many countries thatborrow from the World Bank. Freshwater (in theform of runoff or groundwater) represents only2.5 percent of the world’s total water resources.2

It is also distributed unequally around the world.

According to one authority, “about three-quarters of the annual precipitation on ourplanet descends on areas that contain less thantwo-thirds of the world’s population” (Hunt2004, p. 42). For example, while the Congo Riveraccounts for some 30 percent of total rainwaterrunoff in Africa, only 10 percent of the Africanpopulation lives close enough to the river and itstributaries to make use of its ample resources.Today, more than one billion people live wherethere is no easily accessible fresh drinking water(Hunt 2004, p. 48). In a warming world, and withprecipitation predicted to change regionally,freshwater shortages will increase in manyregions where it is already scarce.

Water usage has increased faster than populationgrowth in the past 100 years, making it evenmore difficult to overcome shortages in someareas (Hunt 2004, p. 40f). In addition, groundwa-ter resources are being depleted through extrac-tion, pollution, and salinization.3 Along with theproblem of decreasing snowmelt (see box 5.1),important freshwater resources are beingdepleted as well, contributing to more runoff inthe short term, but reducing freshwater re-sources in the longer term.

IEG reviewed the results of the Bank’s strategicapproach to water resources in BridgingTroubled Waters (IEG 2002). The study con-cluded that groundwater mismanagement hashad profound social and environmental impactsin borrower countries. The study showed thatlittle is actually done to reduce inland anddownstream risks.

Defined as the loss or continual degradation offorest cover, deforestation has both natural andhuman causes,4 but little can be done about theformer. Loss of forest habitat due to human

causes is attributed to agriculture, urban sprawl,livestock grazing, unsustainable forestry prac-tices,5 mining, and petroleum extraction.

Rates of deforestation (this section is partiallybased on Chomitz 2007) have been driven up bypoverty, as well as a demand for farmland andfuelwood (see box 5.2). If deforestation contin-ues at the rate prevailing at the end of the lastcentury—ranging from 55,000 to 120,000 squarekilometers per year6— all tropical forests will bedestroyed by 2090. Deforestation is continuing ata rapid pace: 130,000 square kilometers a year,according to the Food and Agriculture Organiza-tion (FAO), an area the size of Nicaragua (FAO2006). Almost all of this loss is in the tropics. Itimposes a host of local and global damages. Inupland watersheds, loss of forests is associatedwith flash flooding and landslides. Forest lossover large areas may exacerbate chronic flooding.

Fires, used to clear forests for cropland andpasture, are a major source of health-threateningsmog and can disrupt transport and industry.According to one estimate (Tacconi 2003), theIndonesian fires of 1997–98 imposed damages ofabout $700 million. Forest and land fires in Brazilare estimated to affect 39 million people.Deforestation also threatens the survival of manyunique plant and animal species—a profoundthreat that is difficult to express in monetary terms.

It is crucial to recognize the widespread impactof forest loss on the climate. Forests affect theclimate in two ways. First, they directly affect theclimate by altering wind flows and water-cyclingpatterns. These effects are poorly understood,but a recent study (Feddema and others 2005)suggests that current patterns of deforestationcould disrupt Asian monsoon patterns and boostBrazilian temperatures during this century by 2degrees Celsius, in addition to the effects fromglobal warming.

Second, tropical deforestation contributesalmost twice as much greenhouse gases to theatmosphere as the world’s car and truck fleet(Baumert, Herzog, and Pershing 2005), and thusis a major contributor to climate change. It is aprofound market and policy failure that farmerscontinue to clear tropical forest for gains of aslittle as a few hundred dollars a hectare, whileindustrial countries are paying up to $10,000 toavoid the same amount of CO2 emissions that areproduced by that hectare’s burnt forests(Chomitz 2007).

Floods are generally considered fast-onsetdisasters, but their root cause may be partly ahistory of progressive environmental degrada-tion in rural and urban areas. Floods aregenerally triggered less by heavy rainfall than bythe silting up of rivers, the reduced absorptivecapacity of soil, flawed infrastructure planning,and inadequate maintenance of existingdrainage and flood control facilities. Loss offorest cover and reforestation with inappropri-ate and/or nonnative species contributesheavily to soil erosion, the deposit of silt inrivers, and overly rapid water runoff. This setsthe stage for flash floods and landslides. Theunrestrained harvest of firewood accompaniesrapid population growth. As pasturage de-grades, pastoralists shift from cattle to sheep,and then goats, accelerating the degradation ofsemiarid ranges and increasing desertificationof overgrazed arid lands.

While deforestation is a major issue in Indonesiaand elsewhere, it is not found by scientists toincrease the number of great or major floods.

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Temperature increases associated with climate change also increaserates of glacier loss and snowmelt. Where loss falls beyond annual re-placement levels, this further contributes to increases in drought andwater scarcity. The retreat of glaciers around the world is well docu-mented and snowmelt has been observed to start up to one monthearlier than previously (Barnett, Adam, and Lettenmaier 2005). One-sixthof the world’s population and one-fourth of the world’s GDP are in re-gions that depend on water from snowmelt and glaciers (Barnett,Adam, and Lettenmaier 2005). As a result of insufficient reservoir ca-pacity in these regions, water is lost to its potential users for good, asrunoff takes it through the rivers and to the sea, never to return. Thescarcity of water also leads some regions to experience increased in-cidences of wildfires (Westerling and others 2006; Running 2006; VanNorden 2006).

Box 5.1: Reductions in Potable Snowmelt

Small to medium-size floods are exacerbated by alack of forest cover, but catastrophic floods, theycontend, could not be avoided by any amount offorest cover. Major floods take place when thesoil simply cannot hold any more water, yet morewater comes.7

Unsustainable agricultural practices are alsoincreasing vulnerability. An IEG review (IEG2002) found that poor drainage spoils as muchland as new irrigation creates. Desertification isalso taking its toll, as improper land use andoverexploitation of dryland resources havethrown fragile ecosystems into tumult, affectingone-third of the planet’s surface and over abillion people. This has rendered populationsmore vulnerable to disaster than ever.

Noninfrastructural Approaches toWatershed ManagementBorrowers’ strong focus on infrastructure as thesolution, combined with poor maintenance,leads to an almost constant need for rehabilita-tion. This common but unsustainable patternmilitates for increased investments in noninfra-structural, protective solutions. These canconsist of technology, the restoration of naturalprotections, or the relocation of settlements andfacilities to less risky areas, among othermeasures. Sometimes creative thinking is all thatis needed. For example, in a 1995 Yangtze Riverflood control project in China, several grantswere provided to finance risk assessments and

what was termed a Decision Support System toimprove decision making for the Yangtze Riverflood operations. A flood risk model was alsodeveloped by local staff and internationalconsultants to predict flood levels under theproject.

The first real-time test of the Yangtze flood modelcame during devastating floods in 1996. As itturned out, the model accurately predicted floodlevels and the decisions based on this modelaverted flood damage of $15 million. Duringfloods in 1998 and 1999, the system alloweddecision makers to avert millions of dollars morein flood damage. According to people involvedin the project, the expenditure of $5 million onnonstructural flood prevention to date hasbrought a return estimated at more than 1,100percent and led to an important technologytransfer.

Wetlands Protect Their SurroundingsLosing wetlands means losing a buffer againstdisaster. Swamps, marshes, mangrove forests,bogs, and similar wetland areas intermediatebetween the mainland and open water bodies.Counterintuitively, softer coastlines oftenprovide the best available protection at thelowest cost. Because wetlands are spongy andsupport a wide variety of plant life, they reducethe risk of flooding,8 reduce the energy of waves,and trap sediments. As an added benefit, theyalso purify the water that flows through them.


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In May 2004, heavy rains inundated the southern part of theCaribbean island of Hispaniola in the border region between theDominican Republic and Haiti. According to the InternationalFederation of Red Cross and Red Crescent Societies (June 1,2004), 400 people died in the Dominican Republic from floods andlandslide and 274 were missing. Just across the border in the moredensely populated Haiti, 1,000 people died and more than 1,600 peo-ple were reported missing. According to NASA, “A key factor inthe intensity of the destruction is the extensive deforestationwithin the associated drainage basins and the presence of set-tlements within the floodplains of rivers.”

The hillsides in this southern area of Hispaniola are drought-prone. They have been subject to logging ever since European set-tlers set foot on the island. The originally forested island was famousfor its valuable pine trees, which were exported, while other trees wereused for charcoal production. In the Dominican Republic, logging wasbanned in 1967. However, no such policies were in place on the Hait-ian side. Thus, viewed from above, the border between the Domini-can Republic and Haiti is marked by green pine trees on the DominicanRepublic’s side, with sparse vegetation and a sudden lack of foreston the Haitian side. While the Dominican Republic retained some 28percent of its forests, the Haitian side retained only 1 percent.

Box 5.2: 2004 Flooding Affects Haiti and the Dominican Republic Differently

Source: Diamond 2005.

Wetlands also provide moisture to theatmosphere that returns as rainfall. Worldwide,there are between 748 and 778 million hectaresof wetlands.9 However, 50 percent of wetlandshave been lost over the past century due to landuse changes, such as draining wetlands foragriculture, channelizing rivers, and turningfloodplains into aquaculture zones.10

Loss of mangroves is particularly felt in coastalareas, where storms and storm surges are nolonger met by these energy-absorbing buffers.Not only do the mangroves offer this naturalprotection, but they also trap runoff long enoughfor it to drop sediments, provide nesting areas forfish and crustaceans, and prevent coastal erosion.Since 1980, the world has lost 5 million hectaresof mangroves (from 19.8 million hectares in 1980to 15 million hectares in 2005 due to conversionof mangroves into aquaculture ponds, settle-ments, rice fields, and tourist resorts). South andSoutheast Asia have experienced particularlydramatic losses due to aqua farming and othercauses (see box 5.3) (Primavera 2005).

Wetlands and Mangroves Figure Largelyin the Bank’s Portfolio To learn more about how the Bank’s work isimpacting wetlands and mangroves, appraisaldocuments for projects approved between 1983

and 2006 were analyzed.11 A total of 329 projects(6 percent) were found to address one or bothissues: 241 project appraisal documentsdiscussed wetlands and 113 projects discussedthe preservation or restoration of coastalmangroves (replanting).

Within Bank projects, attention to wetlands andmangroves has been steadily increasing duringthe review period (since 1983) (see figure 5.1).The number of projects that address these fragileecosystems peaked (at least temporarily)between 1992 and 2003. The increased attentionto wetlands can probably be explained by theadoption of environmental safeguard policies OP4.00 in 1989 and OP 4.01 (1991 on environmen-tal assessment), which stipulate the identifica-tion of potential impacts to wetlands during theenvironmental screening process. Since theadoption of environmental safeguards, taskmanagers have paid a great deal of attention towetlands, both along rivers and lakes and alongthe coast. The study did not find an explanationfor the precipitous drop in the last four years.

Task managers had an additional concern inpreserving and protecting wetlands—the Bank issignatory to the Ramsar Convention onWetlands.12 The 1983 Indonesia Second Provin-cial Irrigation Development Project justified itsattention to mangrove preservation by notingthe critical role that mangroves play as a sourceof food for coastal fish and shrimp. Projectdocuments also call for strict monitoring andcontrol of the use of pesticides to prevent toxicagricultural drainage effluents from reachingthese critical feeding and breeding grounds.

While the preservation of wetlands is important,the reforestation of mangroves and the reclama-tion of wetlands warrant a higher priority, giventhat 50 percent of wetlands have been lost overthe past century. The borrowers and the Bankagreed to replant mangroves and to expandwetlands in 40 projects (about 12 percent of the329 projects identified).

The 2002 Bulgaria Wetlands Restoration andPollution Reduction Project represents good

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In 1992, the World Bank funded a shrimp and fish culture project in threeIndian states (Andhra Pradesh, Orissa, and West Bengal). The Bank com-mitted $85.0 million in order to alleviate poverty through employment cre-ation at shrimp and fish farms. Mangrove forests were depleted tomake space for shrimp farms. When cyclones hit the newly denudedcoast, however, they found little resistance. And a significant part ofthe investment was lost. Two cyclones, one in Andhra Pradesh in 1997,and one in Orissa in 1999, destroyed the newly constructed sites forshrimp farming completely. In addition to the risk from hurricanes,shrimp farms, while clearly having some economic benefits, also breedfish and shrimp diseases, and cause the salinization of soil and freshwater, as well as coastal pollution due to wastes and unused foodnutrients.

Source: IEG data.

Box 5.3: Shrimp and Fish Culture Raise Vulnerability

practice, as far as can be determined by deskwork. The project helped local communities andlocal authorities to demonstrate the use ofwetlands as nutrient sinks, thus ameliorating to asmall degree the pollution problems of theDanube River and Black Sea. The project alsohelped to conserve Bulgaria’s globally significantbiodiversity, and it demonstrated how ecologi-cally sustainable agricultural activities canimprove livelihoods.

The desk-based evaluation of Bank work withwetlands is challenged by the imbalance betweenlavish upstream attention and the lack ofdownstream reporting. During preparation, theBank and the borrower discuss potential harm towetlands and mangroves, as well as toendangered plant and animal species in theseareas. Sixty-eight projects discussed potentiallynegative impacts of Bank-funded projects onwetlands and mangroves in the appraisaldocuments. By the time projects close, however,self-evaluation reports tend to be silent aboutproject achievements in this area and they rarelypay any attention to the project’s negative orunanticipated effects on these fragileecosystems.

Notes1. See Milly and others 2002, p. 514. Milly and others

(2002) investigated risks of great floods—that is,floods with discharges exceeding 100-year levelsfrom basins larger than 200,000 km2—using bothstream flow measurement and numerical simula-

tions of the anthropogenic climate change associ-ated with greenhouse gases and direct radiativeeffects of sulphate aerosols. What may be true forgreat floods does not seem to hold for smallerfloods. For example, Kundzewicz and others(2004) analyzed information from 195 rivers,primarily in North America, Australia, the Pacific,and Europe. They examined information onextreme daily flows. According to the observedincreases in precipitation, river flooding wasexpected to increase. However, Kundzewicz andothers did not find a global increase in flooding.What they found was that instances of daily flowmaxima increased regionally—for example, inEurope.

2. “The Earth contains a total of about 1.385 billionkm of water; of this, approximately 35 million km,or 2.5 percent, is freshwater” (Hunt 2004, p. 41).

3. “When the natural equilibrium is disturbed byhuman activities such as over pumping (i.e., morewater is taken away from the aquifer than is replen-ished by precipitation), the saline water body willmove inland, replacing the depleted fresh water—with the progress of the interface determinedmainly by the pumping rate” (Munasinghe 1990).

4. “Natural deforestation can be linked to tsunamis,forest fires, volcanic eruptions, glaciation anddesertification.” Retrieved on May 12, 2006http://en.wikipedia.org/wiki/Deforestation

5. Logging and heavy grazing alone can reducevegetation enough to increase erosion.

6. Between 1960 and 1990.7. For more information see Kaimowitz 2005; Bonell

and Bruijnzeel 2005; and FAO, CIFOR 2005.8. “When precipitation and runoff are stored in

wetlands and flood flow velocity is reduced, thetiming and magnitude of flood peaks is altered.


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Figure 5.1: Bank Focus on Wetlands and Mangroves Peaked Between 1992 and 2003

0

5

10

15

20

25

30

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

Num

ber o

f pro

ject

s

Source: IEG data.

This can lead to a more stable biological com-munity downstream” (Hunt 2004, p. 27).

9. Retrieved on September 29, 2006 from: http://www.iucn.org/en/news/archive/2006/02/02_wetlands_day.htm

10.Retrieved on September 29, 2006 from:http://www.iucn.org/en/news/archive/2006/02/02_wetlands_day.htm Also see Bogena and others2004.

11.Bank data show that 6,108 projects were approvedbetween 1983 and 2006. IEG analyzed 5,804project appraisal documents (Staff AppraisalReports, Project Appraisal Documents, and

Reports of the President) approved between 1983and 2006. The remaining 304 documents were notavailable in ImageBank. A total of 329 projects (or6 percent) considered wetlands (241 projects)and/or mangrove forests (113 projects).

12.By preserving wetlands, the Bank supports theRamsar Convention on Wetlands, signed inRamsar, Iran, in 1971, which currently lists 1,634wetland sites totaling 145.6 million hectares in the Ramsar List of Wetlands of InternationalImportance. Retrieved on December 13, 2006from: http://www.ramsar.org

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CHAPTER 6

Implications for the Bank

Climate Change and Sea Level Rise With flooding and tropical storm disasters on therise, countries would be well advised to considerincreases in their protective investments.Unfortunately, while the Bank is lending forinvestments that reduce vulnerability, thoseloans have mostly focused on the reconstructionof infrastructure when environmental restora-tion may have been more strategically appropri-ate. More troublesome, even when infrastructureis the solution, what is being built by the borrow-ers is not a significant step forward becauseinternational assistance is being used simply torepair what was there already, and the institu-tions necessary to take charge of maintenanceand management too often are not in place. Thisreport has shown clearly that much publiclyfinanced infrastructure is not holding up whenweather-related disasters occur.

The degree to which climate change, itself acontributing factor in the increase in naturaldisasters, has been helping to accelerate theeffects of disasters is not yet adequatelyunderstood. Nonetheless, former Bank chiefeconomist Sir Nicholas Stern argues that, as aresult of climate modification, the world isincreasingly likely to experience major disrup-tions to economic and social activity on a scalesimilar to that associated with the great wars andthe economic depression of the first half of thetwentieth century.

Climate change theory and modeling predictthat as the oceans become warmer, the power oftropical storms will increase (Emanuel 2005).Scientists have documented a more thandoubling in tropical storm intensity in the NorthAtlantic and western North Pacific (Emanuel2005). The National Center for AtmosphericResearch and others have also observed an

increase in the number and intensity of categoryfour and five tropical storms (Webster and others2005).

What impact will this have on flooding? Notsurprisingly, total land precipitation in equatorialregions and high latitudes in the NorthernHemisphere is also increasing.1 Increases areregion-specific, however. Wet areas are be-coming wetter and dry areas are becoming drier.The El Niño-Southern Oscillation, which appearsto have increased in intensity and frequency, is amajor driver behind observed changes, bringingmore intense rain for some regions and severedroughts for others (Dore 2005, p. 1168).

Melting ice has led to a rise in sea levels that hascontributed to an increase in flooding in coastalareas.2 Not all of the observed increase is afunction of receding ice caps of Antarctica andGreenland, however. Water expansion also occurswhen ocean temperatures increase, although thisphenomenon contributes less than half of therise.3 As noted, a percentage of the observed sea-level rise is due to the addition of water to theoceans from the melting of land ice.4

Sea-level rise has been identified as the mostimportant factor leading to accelerating rates ofcoastal erosion (Zhang, Douglas, and Leather-man 2004, p. 55). While it is a slow process, theconsequences of the possible 2 meter rise by theend of the twenty-first century5 will affect themore than 100 million persons living within onemeter altitude of mean sea level, not to mentionthe several hundreds of millions more that maybe living there by then (Zhang, Douglas, andLeatherman 2004, p. 41). Bangladesh, China, andIndia have large low-lying and densely populatedareas and one-quarter of Africa’s population livesin coastal zones.6

Delta areas are especially vulnerable becausethey are made from loosely packed sediment andthey rarely rise more than a few meters above sealevel. They are prone to flooding from stormsurges and also from river overflow. The scope ofthe problem is large: the 40 largest deltas of theworld are home to about 300 million people.According to current predictions, by 2050 onemillion people living in the Ganges-Brahmapu-tra-Meghna delta in Bangladesh, the Mekongdelta in Vietnam, and the Nile delta in Egypt willbe directly affected by sea-level rise (Ericson andothers 2006, p. 78). More broadly, the modelingthat has been done suggests that storm surgesand sea-level rise will affect developing countriesdisproportionately.

While the latest IPCC report predicts a range of0.18 to 0.59 meters in sea level rise this century,some scientists caution that there are manyaspects of sea level rise that are still poorlyunderstood, including factors affecting thepotential catastrophic collapse of ice sheets inGreenland and Antarctica (Kerr 2007). Hencepolicy making needs to take into consideration asmall but salient probability of extremeoutcomes. A forthcoming IEG study will look inmore depth at climate change issues.

Reducing Vulnerability to NaturalDisasters May Help with Adapting to Climate Change As this report has shown, there are sometimesvery effective nonstructural ways to reducevulnerability. And even when it is possible toincrease resiliency by building additional newprotective infrastructure, the Bank and itsborrowers often just repair decaying infrastruc-ture that either was not designed well enough,was not well sited, did not take into accountstakeholder needs, or was not maintained.

For the most vulnerable borrowers, emergen-cies of a scale that require internationalassistance can be nearly an annual occurrence.This implies that mitigation measures promotedby development institutions need to increasethe attention they give to protecting countryinvestments and protecting people and design-

ing interventions that do not worsen thesituation. But at the same time, they need toinclude in their calculus that people may not justbe potential victims of disasters, but the cause ofthem as well (see box 1.2).

With more and more people settling in fragileareas, the level of social, environmental, andeconomic vulnerability to natural disaster isrising rapidly. This heightened vulnerability,combined with the increasing intensity ofhydrometeorological hazards, can be expectedto have strong impacts in the future. The goodnews is that for countries that have not yetadapted to rainfall variability, the same actionsthat reduce vulnerability to disaster also helpwith adaptation to climate change.

Findings of this ReviewThe review of Bank-financed developmentactions in the face of tropical storms and floodingsuggests some preliminary conclusions that willneed to be further examined in subsequent,more detailed evaluative work. Among thefindings are the following: • It is easier to design infrastructure to re-

duce vulnerability than to reverse degra-dation. Of course, underdimensioned orpoorly sited actions taken to reduce disastersexacerbate them, but even well-designed in-frastructure is not always a solution. Adapta-tion to climate change and reduction ofvulnerability to natural disasters are essentiallythe same thing, especially for those coun-tries that have not yet managed to cope withrainfall variability. In many instances long-term, maintenance-free sustainability requiresenvironmental restoration.

• Protecting human settlements against floodsand tropical storms requires developmentstrategies that include building codes andland use planning. This is a particularly strongneed in urban areas, where zoning is most ap-propriate. The nature of losses in rural areasis very different and requires approaches tai-lored to prevailing economic activities.

• Measures to reduce vulnerability to stormsand floods need to be taken in all appropri-ate sectors. Ministries of environment and na-

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tional disaster agencies are often weak. Henceit is important to engage other ministries in thework of vulnerability reduction. For example,the staff of the Ministry of the Environment can-not set out to build watershed-friendly roads.They have never built a road. Local govern-ments also will need to play an increasinglylarger role in planning processes.

• Flooding and tropical storms are commonlytransboundary problems and may requireregional or global solutions. The sensiblemanagement of disaster-related problems hasvaried scales, and points of intervention alsovary. When the problem is transborder in na-ture, the solution needs to be as well.

• The poor are most at risk and most affected bydegradation and disasters. But before identi-fying solutions, it is important to check whetherthey may also be contributing to the degrada-tion. When they are, the solutions often havea livelihoods dimension. In many cases thepeople raising the disaster vulnerability of anarea benefit economically by doing so.

• Women do not have the same vulnerability pro-file as men. Only one woman for every threemen survived the flooding following the De-cember 2004 tsunami in one district in Aceh. Intwo other districts, females accounted for nearly80 percent of deaths. Evidence on women’sdeaths greatly outnumbering men’s also can befound in studies of the flooding that followedthe 1991 Bangladesh cyclone. Because of theirplace in society and the role they play (food forthe family, water and firewood collection, agri-culture) women are the most affected bychanges in the environment and vulnerabilitylevels. There is some evidence, however, thatthey are more likely than men to organize at thecommunity level to limit their risk.

• Land that has important environmental pur-poses provides large public, but few private,benefits. Sometimes the source of a problemis found in places distant from where its impactsare felt. Governments have generally been un-able to assert ownership or control of envi-ronmentally sensitive zones against populationpressure from the poor or land grabs by the richand well-connected.

Notes1. The IPCC (2001) noted a statistically significant

increase in land precipitation of the middle and high latitudes, primarily in the NorthernHemisphere, over the twentieth century. Accord-ing to the Technical Summary of the IPCC (2001):“Overall, it is likely that for many mid and highlatitude areas, primarily in the Northern Hem-isphere, statistically significant increases haveoccurred in the proportion of total annual precip-itation derived from heavy and extreme precipita-tion events; it is likely that there has been a 2 to 4percent increase in the frequency of heavy precip-itation events over the latter half of the 20thcentury.” Retrieved on August 18, 1005 from:http://www.grida.no/climate/ipcc_tar/wg1/pdf/WG1_TAR-FRONT.PDF

2. Alley and others find that over the last century, “sealevel rose ~1.0 to 2.0 mm/year, with waterexpansion from warming contributing 0.5 + 0.2mm […] and the rest from the addition of water tothe oceans […] due mostly to melting of land ice”(Alley and others 2005, p. 456).

3. Water expansion from warming contributes 0.5 to0.2 mm to sea-level rise, (Alley and others 2005, p.456).

4. It was also found that past changes in atmosphericCO2 were correlated with global sea levels. (Alleyand others 2005, p. 456).

5. Anthoff and others 2006. The work was preparedfor the Stern Review on the Economics of ClimateChange.

6. Nyong 2005, p. 13: “40 percent of the population ofWest Africa lives in coastal cities and it is expectedthat the coast between Accra (Ghana) and theNiger delta (about 500 km) become a continuousurban megalopolis with more than 50 millionpeople by 2020 (Hewawasam 2002). The shorelineof East Africa (11,000 km long) is occupied by 30 to35 million people. By 2015, three megacities withat least 8 million people will be present in coastalAfrica (Lagos, Kinshasa and Cairo) (Klein andothers 2002). These characteristics explain themain problems encountered in the coastal zone,mainly pollution, resource and land use conflicts,overexploitation of ecosystems and species.”http://www.stabilisation2005.com/Tony_Nyong.pdf


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