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Selected Satellite Images ofOur Changing Environment

Copyright 2003, United Nations Environment Programme

ISBN: 92-807-2272-5

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United Nations Environment ProgrammeDivision of Early Warning and Assessment-North America47914 252nd Street, EROS Data Center, Sioux Falls, SD 57198-0001 USATel: 1-605-594-6117Fax: 1-605-594-6119info@na.unep.netwww.na.unep.netwww.unep.org

For bibliographic and reference purposes this publication should be referred to as:

UNEP (2003), “Selected Satellite Images of Our Changing Environment”. UNEP/DEWA/RS.03-1Division of Early Warning and Assessment (DEWA)United Nations Environment Programme (UNEP)P.O. Box 30552Nairobi, Kenya

DISCLAIMER

The views expressed in this publication are not necessarily those of the agencies cooperating in this project. The designations employed and the presentations do not imply theexpression of any opinion whatsoever on the part of UNEP or cooperating agencies concerning the legal status of any country, territory, city, or area of its authorities, or thedelineation of its frontiers or boundaries.

Mention of a commercial company or product in this report does not imply endorsement by the United Nations Environment Programme. The use of information from thispublication concerning proprietary products for publicity or advertising is not permitted. Trademark names and symbols are used in an editorial fashion with no intention ofinfringement on trademark or copyright laws.

We regret any errors or omissions that may have been unwittingly made.

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Selected Satellite Images ofOur Changing Environment

United Nations Environment Programme

2003

Acknowledgments

UNEP acknowledges the contributions made by many indi-viduals and institutions in the preparation and publication ofSelected Satellite Images of Our Changing Environment. Afull list of names is included on page 124.

Production and Support Team

Ashbindu SinghKim GieseNazmul HossainMark A. ErnsteShingo IkedaAnil RaghavanSandra PrinceMichael PoppenRynn Lamb

Eugene FosnightJane S. SmithElitsa PenevaPascal PeduzziHassan PartowJesper KofoedNicole StrubChristian LambrechtsDominique Del Pietro

Editorial Review Team

Dr. Adrian NewtonMr. S. K. Puri

To obtain a copy of the report, please contact:

Ashbindu Singh, Regional CoordinatorUNEP/GRID – Sioux FallsUSGS/EROS Data Center47914 252nd StSioux Falls, SD 57198Phone: (605) 594-6117Fax: (605) 594-6119E-mail: singh@usgs.gov

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FOREWORD vii

INTRODUCTION viii

Overview of Satellite Imagery ix

Site Locator Map ixThe Earth at Night, Where We Live xThe Earth During the Day, theEnvironment We Live In xiiOur Forests xiv

AFRICABanjul Region, Gambia 2Challawa Gorge Dam, Nigeria 4Itampolo, Madagascar 6Lake Chad, Chad 8Lake Nakuru, Kenya 10Lake Victoria, Uganda 12Lesotho Highlands Dam, Lesotho 14Midrand, South Africa 16Mount Kilimanjaro, Tanzania 18New Valley Project, Egypt 20

ASIAAl Isawiyh, Saudi Arabia 24Aral Sea, Kazakhstan 26Atatürk Dam and Harran Plain, Turkey 28Beijing, China 30Dhaka, Bangladesh 32Oil Well Fires, Kuwait 34Huang River Delta, China 36Irian Jaya, Indonesia 38Isahaya Bay Reclamation, Japan 40Lake Hamoun, Iran/Afghanistan 42Mesopotamian Wetlands, Iraq/Iran 44New Delhi, India 46Paektu San Region, Korea, DPR 48Phnom Penh, Cambodia 50Shenzhen, China 52Sundarban, Bangladesh/India 54Thailand Aquaculture, Thailand 56Three Gorges Dam, China 58

AUSTRALIA/OCEANIACape York Bauxite Mining, Australia 62Wyperfeld National Park, Australia 64

EUROPEGabcikovo, Slovakia/Hungary 68IJsselmeer, The Netherlands 70Taiga Forest, Russia 72

NORTH AND CENTRAL AMERICAEverglades, United States 76Gulf of Fonesca, Honduras 78Hayman Wild Fire, United States 80Las Vegas, United States 82Mexico City, Mexico 84Mount St. Helens, United States 86Tensas River Basin, United States 88Vancouver and Seattle, Canada/United States 90

SOUTH AMERICABrasilia, Brazil 94Gulf of Guayaquil, Ecuador 96Iguazú National Park, Argentina 98Manaus, Brazil 100Rondônia, Brazil 102Santa Cruz, Bolivia 104Santiago, Chile 106

ANTARCTICAFilchner Ice Shelf, Antarctica 110Larsen Ice Shelf, Antarctica 112

ANNEXESReferences 115Contributors 124Acronyms and Abbreviations 124

Table of Contents

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Scientifically valid environmental data and information arecrucial to gain understanding of global change impacts andcauses as well as to support enlightened decision-making.While collection and analysis of scientifically credibleenvironmental information, particularly for developingregions, continues to be a major challenge, visualizing andcommunicating environmental changes through appropri-ate use of available information is also proving to be anequally arduous proposition. The latter can be particularlyuseful in understanding the outcome of human inducedinterference in natural systems, and in settings where thedecision maker can explore alternative scenarios anddevelop a deeper knowledge of the context of decisions. Itshould be noted that even developed countries benefit fromvisualizing the complexities of environmental changes usingsatellite data, for example to detect changes in an ecosystemover time.

The overall objective of UNEP's Division of Early Warn-ing and Assessment (DEWA) is to improve the knowledge ofdecision-makers at national and international levels withregard to global environmental trends, condition andemerging issues. To assist countries with their goal of sus-tainable development, UNEP provides these data sets onland cover changes to illustrate the impacts of existingpolicies on societal behaviors in land management andenvironmental protection.

UNEP has developed a deep understanding of thecritical role of data in general, and satellite imagery in

Forewordparticular, in its endeavor to raise the profile of environmen-tal issues across all levels of governments and societies. UNEPproposes to strengthen its links with relevant institutions inindustrialized countries to enhance visualization of scientificinformation and encourage them to make such data acces-sible to developing countries. The identification, acquisitionand dissemination of satellite imagery of critical ecosystemswill help build capacity of national-level institutions to under-take their own environmental assessments and to reportmore effectively to satisfy their obligations under variousconventions. Improved, integrated State of the Environmentreporting at the national level is expected to enhanceUNEP's ability for such reporting at the global level.

This publication Selected Satellite Images of Our ChangingEnvironment uses satellite images to document environmentalchanges during the last thirty years in 50 selected sitesaround the world. I hope the information provided will notonly be useful in the context of selected locales, but will alsounderscore the intrinsic value of harnessing, visualizing andcommunicating technologies to gain a deeper understandingof the dynamics of environmental changes.

Daniel ClaasenActing Director

United Nations Environment ProgrammeDivision of Early Warning and Assessment

Left: NASA Goddard Space Flight Center—Reto Stöckli, Robert SimmonRight: USGS—Sundarban Reserve Forest, Landsat, 2000

IntroductionMany countries face multiple challenges arising from rapiddegradation of critical natural resources, and many otherenvironmental constraints. These constraints include inad-equate rainfall and an unsustainable increase in the pressureon available resources owing to a rapidly burgeoning humanpopulation. These challenges underscore the critical andurgent need to properly manage and conserve the naturalresource base. An effective management strategy must drawon a clear view of the current state of the environment, anunderstanding of local and regional trends and the factorsdriving those trends.

Increasing concern over how human activities interactand influence the global environment have led to the initia-tion and formulation of a number of environment assess-ment programs, treaties and agreements which call forincreased, systematic observation of Earth systems. Suchsystematic observations require consistent, geographicallyreferenced data that can be acquired over large areas repeat-edly and at a reasonably low cost, using remote sensingtechnology. Since the launch of the first MeteorologicalSatellite in 1960, satellite remote sensing has emerged to be acost-effective method for conducting time-series, large-scaleobservations of the Earth's systems. Satellite images can beused to map the entire world and to generate a number ofglobal datasets needed for various thematic applications.

This publication directly addresses these issues by focus-ing on a number of “hot spots” (i.e., locations that haveundergone very rapid environmental change) by using state-of-the-art remote sensing and spatial data integration tech-niques to analyze and document these changes over a 30-yearperiod (1972–2001). The hot spots cover major and diverse

themes across the world, ranging from forest coverchange in Rondonia (South America), urban sprawl inLas Vegas (North America), drying of Lake Chad (Africa),demise of wetlands in Mesopotamia (West Asia), emergingurban growth centers in Asia, to the ice shelf collapse inPolar regions.

The primary data source for this project is the Landsatarchive of digital satellite data housed at the USGS EROSData Center, Sioux Falls, South Dakota. This uniquearchive is the longest running enterprise for the acquisi-tion of satellite imagery of the Earth’s surface from space;it thus provides a periodic and immensely valuable recordof the state of the global environment dating back to1972. Landsat was the first Earth observation satellitedeveloped by NASA. Landsat 1 was launched on July 23,1972. Since then, six additional satellites have beenlaunched, the latest in 1999. Landsat data are arguablythe most extensively used satellite datasets in the world;their applications range from global change research toassessment of land use/land cover, forest fires, forestry,agriculture, hydrology, natural disasters, and also manyother disciplines. These datasets are being used by inter-national, regional and national institutions representinggovernment, commercial, industrial, civilian, military, andeducational communities worldwide.

The analyses made in this publication directly contrib-ute to the mission of UNEP capacities to provide objectivedocumentation and scientific evidence of environmentalchanges to governments and international developmentagencies, as well as civil society.

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Overview of Satellite ImageryPolicy makers, managers, scientists and the public can viewthe changing environment using satellite images. Morethan 60 Earth observing satellites are collecting images ofthe Earth’s surface. Remote sensing satellite systems forland cover assessment are operated by a grow-ing number of countries including theUnited States, Japan, France, Canada,Russia and India.

The focus of this Atlas is satellitesystems for land cover monitoring.The information presented will helpassess the utility of remotely sensedimages to meet the needs of deci-sion-makers.

Remote sensing is the discipline ofobserving the Earth's surface withoutbeing directly in contact with it. It allowsus to obtain information about our planetand the human activities that affect it from a distance.Remote sensing can reveal interesting features that maynot be possible or affordable to assess from ground level.This gives a global perspective on changes and the interac-tion of our complex biosphere components.

The tools for remote sensing are sensors installed onaircrafts or satellites. Airborne sensors are typicallyphotographic cameras. Although an important source ofenvironmental information, airborne image collectionsoften are poorly documented for small areas. In many

countries the collection of airborne photo-graphs is restricted. Satellite sensors

acquire images of the Earth and trans-mit the data to ground receiving

stations located throughout theworld. Once these raw images areprocessed and analyzed, they candocument changing environmen-

tal conditions like pollution, globalclimate change, natural resource

management, urban growth, andmuch more. Even though many satellite

sensors monitor the Earth, the choice ofwhich sensor to use depends on the type of environ-

mental information needed.

This Selected Satellite Images of Our Changing Environ-ment atlas uses satellite images, particularly Landsatimages to show changes in the global environment overthe last 30 years.

Site Locator Map

The Earth at Night, Where We Live

This image shows the pattern of stable night-lights on theEarth’s land surface. This pattern of night-lights intertwinestwo important variables related to human populations andthe environment: population density and energy consump-tion. Cities and towns with greater populations tend to bebrighter and larger. Societies that consume proportionallygreater amounts of energy or which consume more land percapita tend to be brighter and larger than other cities withthe same population.

Locally and regionally, night-lights show patterns ofpopulation concentrations. Within North America, the even

distribution of population drops off quickly in arid, semiarid, mountainous, polar and tropical regions. Populationsin arid and semi arid areas are concentrated in major urbancentres, where water is often brought in from long distancesor mined from fossil aquifers. In the north, the populationdensity drops off quickly as the climate becomes too cold tosupport agriculture. In mountainous areas and in thetropics where arable lands are not evenly distributed,likewise the human populations are not evenly distributed.Transportation nets are visible as strings of lights. Thesepatterns are equally strong on all the continents. Large

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sparsely populated areas exist in South America, Africa andCentral Asia where lights are few. Regionally this can becaused either by low population densities or low consump-tion of energy.

Regionally and globally, night-lights show patterns ofenergy consumption and economic development. LosAngeles, Paris, Buenos Aires, Shanghai, Cairo and Calcuttaall have approximately the same population, but the areaoccupied by the cities and the amount of energy consumedvary considerably. Densely populated countries like Chinaand India do not show the dense network of lights visible inJapan, Europe or the Eastern United States. A dramaticvariation in energy consumed can be seen regional in areassuch as the Korean Peninsula. Access to cheap power, such

as in the Nile Valley below the Aswan Dam or along thePersian Gulf, create localized areas of high energy consump-tion that may not be typical of the more general society.

Threats to the environment are not simply a function ofpopulation growth. Equally important is the increasing trendin energy consumption per capita. Ultimately, stabilizingpopulation growth may prove easier than stabilizing con-sumption. Not only do human populations continue to grow,but each person continues to make greater demands uponthe environment. This trend toward a greater impact ofpeople upon the environment is documented in the imagesthat follow.

The Earth During the Day,the Environment We Live In

One quarter of the Earth’s surface is covered by land. Thedarkest greens are in the boreal forests of the north and therain forests of the tropics. The sparse boreal and coniferousforests of the polar zones sit on heavy organic soils that haveaccumulated organic matter for millennium through slowdecomposition in damp, cold soils. Conversely, the densetropical forests sit on leached soils with little organic matter;

here the organic matter is held in the vegetation mass. Thebrighter greens are the grasslands during rainy seasons andagricultural areas under production. Deciduous temperateforests tend toward a medium green. The whites, tans,browns and reds are arid and semi-arid lands with many soilcolors and mixtures of sparse vegetation. Transition zonesbetween these colors are usually grasslands and woodlands at

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various stages of development. Within lakes and seas thegreens and blues show shallows, vegetation or suspendedsediment. This image is lain over a shaded relief base, whichemphasizes mountains and hilly landforms.

Water, temperature and fire set limits on what ecosystemscan thrive. Lightening and people set the fires that promotefire tolerant species in many ecosystems. Immense fires haveraced through the grasslands and boreal forests. In nearly allecosystems, people have been the primary source of fire.

Until recently tropical fires were on a smaller scale. Aspeople expand into tropical ecosystems, these too are being

affected by fire. People are rapidly expanding into nearly allecosystems. The protection of some of these ecosystems isnecessary. The destruction and non-sustainable use of natu-ral ecosystems impacts the capacity of the ecosystems tosupport people through food production, freshwater, protec-tion from flooding, and forest products. People need tocoexist with natural ecosystems to ensure the continuedexistence of all.

ARCTIC C

ANTARCTIC CIRCLE

EQUATOR

TROPIC OF CANCER

Our ForestsForests are important elements for sustaining the ecologicalhealth of the Earth. The forest map of the world shows fivemajor categories - closed forest (dark green); open andfragmented forest (light green); other wooded land (darktan); other land cover (light tan); and water (blue). Forestcover maps can be used to monitor sustainability of forestecosystems, and estimate forest biomass by country, ecologi-cal zone, climate region, and other terrestrial characteristics.

Forests, as is the case with all land cover, are manipulatedby climate. In the cold regions of high latitudes exist Boreal

Coniferous Forests. In the humid temperate zone areBroadleaved Deciduous Forests of eastern North America,Western Europe, and Eastern Asia. The Mediterraneanclimate’s mild and humid winters and hot dry summerssupport the Sub-Tropical Dry Woodlands, which are scatteredaround the world in regional climatic zones. Tropical DryForest and Woodlands occur in tropical regions, most com-monly in Africa, with pronounced dry seasons. TropicalRainforests exist in the equatorial zones, where the climate is

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hot and humid throughout the year. Mountain Forests oftencontain local endemic ecosystems that differ from the low-lands that surround them. Mangroves are highly productivecoastal ecosystems along the tropical and subtropical coast.Forest plantations, a growing proportion of the forest area,provide forest products in an essentially monoculture ecosys-tem that helps to lessen logging in the natural forest.

Many of these forests are threatened. Among the mostthreatened are the Mangrove and Mountain Forests that

exist as isolated and unique ecological systems that arenot resilient to development. All forests are under threatof fragmentation and non-sustainable utilization offorest resources.

CIRCLE

TROPIC OF CAPRICORN