Climate

Impact

Assessment

Impact Assessment and Applications Section Climatology and Agrometeorology Division

Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA)

Department of Science and Technology

APRIL 2011

Number 04 / Volume 27

The Impact Assessment and Applications Section

(IAAS) of Climatology and Agrometeorology Division (CAD) regularly issue this monthly/bulletin which will provide users such as food security managers, economic policy makers, agricultural statisticians and agricultural extension officials with qualitative information on the current and potential effects of climate and weather variability on rainfed crops, particularly rice and corn. This bulletin, entitled “Climate Impact Assessment for Agriculture in the Philippines”, represents a method for converting meteorological data into economic information that can be used as supplement to information from other available sources.

For example, an agricultural statistician or

economist involved in crop production and yield forecast problems can combine the assessment with analysis from area survey results, reports on the occurrence of pests and diseases, farmers reports and other data sources.

The impact assessments are based on agroclimatic

indices derived from historical rainfall data recorded for the period 1951 to the present. The indices, expressed in raw values percent of normals and percentile ranks, together with real time meteorological data (monthly rainfall, in percent of normal), percent of normal cumulative rainfall, as well as the occurrence of significant event such as typhoons, floods and droughts are the tools used in the assessment of crop performance. Crop reports from PAGASA field stations are also helpful.

The narrative impact assessment included in the

bulletin depicts the regional performance of upland, 1st lowland and 2nd lowland palay; and dry and wet season corn crops, depending on the period or the season. Tabulated values of normal rainfall and generalized monsoon and yield moisture indices are provided for ready reference. Spatial analysis of rainfall, percent of normal rainfall and the generalized monsoon indices in percentile ranks are also presented on maps to help users visualize any unusual weather occurring during the period. The generalized monsoon indices in particular, are drought indicators; hence, the tables (see Appendices) together with the threshold values can be used in assessing drought impact, if there are any. It also help assess any probable crop failure.

It is hoped therefore that this bulletin would help provide the decision-makers, planners and economist with timely and reliable early warning/information on climatic impact including the potential for subsistence food shortfalls, thereby enabling them to plan alternate cropping, if possible, food assistance strategies / mitigation measures to reduce the adverse impact of climate and eventually improve disaster preparedness.

Impact assessment for other principal crops such as sugarcane and coconut, for energy and for water resources management, are from time to time will be included in the forthcoming issues of this bulletin.

The IAAS of CAD will appreciate suggestions/comments from end-users and interested parties for the improvement of this bulletin. Definition of Terms

The Generalized Monsoon Index (GMI) helps determine the performance of the rains during the season and serves as a good indicator of potential irrigation supplies. It is a tool used to assess rainfed crops.

The GMI for the southwest monsoon (GMIsw) in an area during June to September is defined as follows:

GMIsw = W6P6+W7P7+W8P8+W9P9 The GMI for the northeast monsoon (GMIne) in an

area during October to January is defined as: GMIne=W10P10+W11P11+W12P12+W1P1

where: W =weight coefficient of monthly rainfall

for the season; P = rainfall amount in the ith month (i=1 for January, i=2 for February, etc.)

The Yield Moisture Index (YMI) is a simple index that helps the users assess agroclimatic crop conditions during the crop season. The YMI for a particular crop is defined as follows:

n

YMI = Pi Ki i where:

I = the crop stage (1=planting/ transplanting, 2=vegetative,

3= flowering, 4 = maturity, etc.) n = total no. of crop stages; P = the rainfall during the ith crop stage; and K = is the appropriate crop coefficient for

the ith crop stage. Tentatively, the threshold values of categories of

indices for interpretation being adopted for both YMI and GMI are as follows:

Percentile Rank

Interpretation

> 80 Potential for flood damage

41-80 Near normal to above- normal crop condition

21-40 Moderate drought impact with reduced yield

11-20 Drought impact with major yield losses

< 10 Severe drought impact with crop failure and potential food shortages

PREFACE

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AAGGRROOCCLLIIMMAATTIICC // CCRROOPP CCOONNDDIITTIIOONN AASSSSEESSSSMMEENNTT

FFOORR AAPPRRIILL 22001111

Overview

REGION I (Ilocos Region)

Farming activities may be hampered in most

parts of the region. Less moisture supply was experienced due to below to way below normal rainfall amount received during the month.

CAR (Cordillera Autonomous Region)

Poor yield is expected for the harvestable

standing crops in the region due to moisture stress experienced by the crops during its critical stages of growth development. Farming activities may possibly be delayed because of less rainfall observed in the area.

REGION II ( Cagayan Valley)

Good yield is expected for the harvestable

standing crops due to sufficient moisture received during the month.

REGION III (Central Luzon) Excessive rains experienced in the eastern part of the region might potentially damage the harvestable standing crops of early planted wet season corn. Crops suffered water clogging during its maturity and ripening stages. It will most likely to produce a very poor yield or no yield at all. However, good harvest is expected for the rest of the region.

REGION IV-A (CALABARZON)

Early planted wet season corn is expected to have a good yield due to sufficient moisture experienced by the crops during its critical stages of development.

The below normal rainfall amount received in the region may hamper the land preparations.

Harvesting of standing crops is expected to have a good yield in most parts of the country due to sufficient moisture supply during its critical stages and growth development. However, in the eastern part, the flooding brought by excessive rains might potentially damage to the harvestable crops as well as water clogging during its maturity and ripening stages and most likely produce a very poor yield. Land preparation of the dry season corn is favorable in some areas.

The tail-end of the cold front, easterly wave, intertropical convergence zone (ITCZ), low pressure

areas (LPAs), ridge of high pressure area (HPA), and one tropical cyclone (TC) were the weather systems that affected the country’s climate for the month of April. Tropical Depression (TD) “Amang” (April 3-4), the first tropical cyclone for this year, did not affect any part of the country. The termination of the Northeast monsoon was declared last April 12, which signals the transition period towards the beginning of the southwest monsoon season characterized by warm and humid weather conditions.

Rainfall analysis for April, however, showed that Regions I, IV-A and NCR, and to a lesser degree

Region III and Region V, had experienced below to way below normal rainfall conditions. Likewise, the Autonomous Region of Muslim Mindanao (ARMM) and most parts of Region X had also experienced below normal conditions. The rest of the country had received near to above normal rainfall. This varying pattern of rainfall distribution suggests a manifestation of a weakening La Niña event.

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REGION IV-B (MIMAROPA)

Harvesting of late planted lowland second palay almost finished, drying and storing started. Good yield is anticipated except for the western part of the region, wherein poor yield is expected due to insufficient moisture during the critical stages of growth development.

REGION V (Bicol Region)

Harvesting of wet season corn is going on. Good yield is likely to happen in most parts of the region due to sufficient moisture experienced by the crops during its reproductive and maturing stage.

Land preparation of dry season corn is

favorable in the southern part of the region. REGION VI (Western Visayas)

Below normal rainfall amount received in most parts of the region will most likely to hinder farming activities, poor yield for the harvestable standing crops is expected.

REGION VII (Central Visayas) Farming activities may be hampered and poor yield for the harvestable standing crops is expected in the region, this is due to the below normal amount of rainfall received and will likely produce moisture stress to the crops.

REGION VIII (Eastern Visayas)

Sufficient moisture supply favors the harvestable early planted wet season corn in some areas of the region. Good yield will likely be produce. However, in the eastern part, the flooding brought by excessive rains may bring damage to the standing crops during its maturing stage and might produce poor yield.

Land preparation for dry season corn just started.

REGION IX (Zamboanga Peninsula)

Sufficient rainfall amount received for the month is favorable for all farming activities to be done, most especially in the northern part of the region.

REGION X (Northern Mindanao)

The below normal rainfall conditions experienced in the region may hamper all farming activities, due to less moisture supply.

REGION XI (Davao Region)

Sufficient moisture needed for farming activities seems favorable, due to ample amount of rainfall received in the region.

REGION XII (SOCCSKSARGEN)

Below normal rainfall amount received during the month may hinder any farming activities needed.

REGION XIII (CARAGA)

Harvesting of early planted wet season corn is going on. Above normal rainfall received in the region most especially in the northern and eastern part might potentially damage harvestable standing crops. Some flooding experienced by the crops during its maturity and ripening stages may produce poor yield as expected. However, the rest of the region might produce good yield.

Land preparation for dry season corn is favorable, due to sufficient moisture supply available during the month.

ARMM ((Autonomous reg. of Muslim Mindanao) Harvesting of early planted wet season corn just started and good yield is expected due to sufficient moisture supply during its critical

stages of development.

For Particulars, please contact:

Thelma A. Cinco

Impact Assessment and Applications Section (IAAS) Climatology and Agrometeorology Division (CAD)

PAGASA-DOST Telefax No.: 434-58-82

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Table 1.0 Cumulative Yield Moisture Indices for Early Planted Wet Season Corn (February 2011 – April 2011) in Millimeters and Percentile Rank.

STATIONS FEBRUARY MARCH APRIL

YMI %RANK YMI %RANK YMI %RANK

Region III (Central Luzon)

Baler 11 4 190 21 353 25

Casiguran 57 38 412 83 701 85

Region IV-A (CALABARZON)

Alabat 261 88 603 79 618 87

Ambulong 0 2 35 87 42 40

Infanta 173 73 679 83 787 83

Tayabas 47 56 265 87 352 81

Region V (Bicol Reg.)

Daet 401 96 846 71 907 92

Legaspi 52 19 574 81 663 81

Masbate 54 58 507 62 571 94

Virac 73 60 473 85 518 85

Region VIII (Eastern Visayas)

Catarman 332 90 1925 67 2130 98

Catbalogan 88 50 953 54 1083 94

Tacloban 196 73 1534 75 1642 98

Region XIII (CARAGA)

Butuan 333 96 687 73 740 96

Hinatuan 732 94 1639 94 1883 94

Surigao 639 90 1940 83 2191 98

ARMM(Autonomous Region of

Muslim Mindanao)

Cotabato 138 96 370 73 427 85

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Table 2.0 Yield Moisture Indices for Dry Season Corn (April-June 2011) in Millimeters and Percentile Rank.

STATIONS APRIL MAY JUNE

YMI %RANK YMI %RANK YMI %RANK

Region IV-A (CALABARZON)

Infanta 94 48

Region V (Bicol Reg.)

Daet 53 50

Legaspi 77 52

Virac 39 38

Region VIII (Eastern Visayas)

Catarman 178 88

Region XIII (CARAGA)

Hinatuan 212 58

Surigao 218 85

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Table 3.0 Decadal and Cumulative Decadal Rainfall (Actual and Percent of Normal) for the month of APRIL 2011

REGION

DECADE ACTUAL

April

% Normal

of Actual

CUMULATIVE

Jan- Apr

% Normal

Cumulative

R01

Ilocos Region

10 4.2 43 69.6 158

11 3.7 24 73.4 124

12 13.7 69 87.1 110

CAR CAR

10 5.0 33 156.8 158

11 21.0 111 177.9 151

12 8.3 39 186.1 133

R02 Cagayan Valley

10 17.8 52 374.0 121

11 83.0 259 457.1 134

12 24.5 82 481.6 129

R03 Central Luzon

10 13.6 40 232.3 125

11 28.8 113 261.1 123

12 16.6 53 277.6 114

R04-A CALABARZON

10 12.7 38 572.3 156

11 24.0 78 596.3 150

12 28.1 98 624.5 146

R04-B MIMAROPA

10 6.5 61 209.5 247

11 21.1 175 230.6 238

12 12.5 60 243.1 206

NCR NCR

10 3.0 27 195.9 234

11 2.5 27 198.4 213

12 3.7 22 202.1 185

R05 Bicol Region

10 17.5 36 1112.7 186

11 31.9 84 1144.6 180

12 46.5 132 1191.0 178

R06 Western Visayas

10 0.3 2 446.0 285

11 16.6 100 462.6 267

12 5.2 18 467.8 232

R07 Central Visayas

10 2.0 12 685.2 278

11 14.5 83 699.7 265

12 14.8 62 714.5 248

R08 Eastern Visayas

10 15.9 35 2380.1 324

11 69.7 207 2449.8 319

12 87.3 200 2537.1 313

R09 Western Mindanao

10 2.4 11 894.4 384

11 10.1 27 904.5 335

12 62.7 243 967.2 327

R10 Northern Mindanao

10 20.4 67 743.1 219

11 6.9 20 750.0 201

12 46.4 131 796.4 195

R11 Davao Region

10 81.8 175 1053.9 182

11 39.6 73 1093.5 173

12 77.1 139 1170.6 170

R12 SOCCSKSARGEN

10 28.2 134 404.3 187

11 27.3 73 431.7 170

12 20.8 65 452.5 158

R13 CARAGA

10 27.4 41 2306.9 208

11 58.9 86 2365.8 201

12 113.4 179 2479.1 200

ARMM

10 16.1 87 598.9 318

11 16.6 48 615.5 276

12 22.5 76 638.0 252

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Fig 1.0 Actual Cumulative Rainfall During the Passage of Tropical Depression “AMANG”

(April 03-04, 2011)

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A. Decade 1 – April 01-10, 2011 B. Decade 2 – April 11-20, 2011 C. Decade 3 –April 21-30, 2011

Fig 2 Ten Days Actual Rainfall Distribution in the Philippines for the month of APRIL 2011

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B. Actual rainfall (mm) C. Percent of Normal Rainfall ( % ) A. Normal Rainfall (mm)

Fig 3 Rainfall in the Philippines for the month of APRIL 2011

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Fig. 4.0 Comparison of Normal Rainfall and Potential Evapotranspiration with the Actual Monthly Rainfall at Laoag, Baguio, Dagupan, Basco, Aparri and Tuguegarao.

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Fig. 4.a. Comparison of Normal Rainfall and Potential Evapotranspiration with the Actual Monthly Rainfall at Iba, Muñoz, Science Garden, Ambulong, Calapan and Port Area. 12

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Calapan

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Iba

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Fig. 4.b. Comparison of Normal Rainfall and Potential Evapotranspiration with the Actual Monthly Rainfal at Puerto Princesa, Casiguran, Infanta, Alabat, Daet

and Legaspi

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Alabat

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Casiguran

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Infanta

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Legaspi

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Fig.4.c. Comparison of Normal Rainfall and Potential Evapotranspiration with the Actual Monthly Rainfall at Cuyo, Iloilo, Dumaguete, Masbate, Mactan and Tacloban.

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Fig 4.d. Comparison of Normal Rainfall and Potential Evapotranspiration with the Actual Monthly Rainfall at Catarman, Cagayan de Oro, Davao, Dipolog, Zamboanga and General Santos.

Vao day nghe bai nay di ban http://thucaithoi.xlphp.net Vao day nghe bai nay di

ban http://thucaithoi.xlphp.net Data at Catarman, Cagayan de Oro, Davao, Dipolog, Zamboanga and General

Santos,

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