CLIMATE IMPACT
ASSESSMENT for
Philippine Agriculture
(Rice and Corn)
MAY 2014 Number 05 / Volume 30
MAY 2020
Number 06 / Volume 36
Impact Assessment and Applications Section (IAAS)
Climatology and Agrometeorology Division (CAD)
Philippine Atmospheric, Geophysical and Astronomical Services
Administration (PAGASA)
Department of Science and Technology
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P r e f a c e
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 helps 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, 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 = crop stage (1 = planting/transplanting, 2 = vegetative, 3 = flowering, 4 = maturity,
etc.) n = total no. of crop stages; P = rainfall during the ith crop stage; and K = 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
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AGROCLIMATIC / CROP ASSESSMENT FOR MAY 2020
OVERVIEW
Land preparation, planting and transplanting activities for upland 1st palay, lowland 1st palay and wet season corn had just started in CAR, Laoag, Basco Batanes, Tuguegarao, Munoz, Baler, Casiguran, Infanta, Tayabas, Legaspi, Virac, Catarman, Catbalogan, Malaybalay, Davao Region, Surigao del Sur and ARMM because of sufficient moisture available in those areas. Contrastingly, any farming activity related to planting rice and corn might be hampered in Vigan, Dagupan, Aparri, Zambales, Calapan, Romblon, Masbate, Panay Island, Region VII, Tacloban, Region IX, Misamis Oriental, Surigao del Norte and SOCCSARGEN due to the inadequate moisture received in those areas. Standing corn crops in Catanduanes and Surigao del sur are in good crops condition, while in Camarines Norte and Surigao del Norte, crops suffered moisture stress.
The weather systems that affected the country during the month were the Northeasterly surface windflow, ridge of High-Pressure Areas (HPAs), low pressure areas (LPAs), Intertropical Convergence Zone (ITCZ), Typhoon (TY) Ambo, easterlies and localized thunderstorm. A persisting warm ENSO-neutral condition has also been observed and is forecasted to continue until the third quarter (July-September) 2020 based on climate models.
REGION I (Ilocos Region) Land preparation, planting and transplanting activities for planting upland 1st palay as well as wet season corn had just started in Laoag; this is due to the ample amount of moisture available in the area. In contrast, other parts of the region received very low rainfall during the month which hampers all farming activities.
CAR (Cordillera Autonomous Region) Sufficient moisture was available during the month which favors land preparation, planting and transplanting activities for wet season corn as well as upland 1st palay across the region.
REGION II (Cagayan Valley) Land preparation, planting and transplanting activities for planting upland 1st palay and wet season corn had just commenced in Batanes and Tuguegarao, since the rainfall amount had been sufficient during the month. Meanwhile, in Aparri, due to very low moisture available in the area, planting activities for rice and corn are hindered.
REGION III (Central Luzon) Land preparation, planting and transplanting activities for upland 1st palay and wet season corn had just begun in most parts of the region, except in Zambales. This is due to the lesser amount of rainfall available in the area during the month.
REGION IV-A (CALABARZON) Land preparation, planting and transplanting activities for planting wet season corn and upland 1st palay had just started in Tayabas, and lowland ist palay in Infanta. It is because of sufficient moisture available in those areas,
REGION IV-B (MIMAROPA) During the month, land preparation for wet season corn as well as upland 1st palay cannot be done in either Calapan or Romblon; it is due to inadequate rainfall received in those areas during the month.
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REGION V (Bicol Region) Inadequate rainfall received in Masbate during the month hindered any farming activity related to rice and corn. On the other hand, sufficient moisture available during the month favors land preparation, planting and transplanting activities for planting wet season corn and upland 1st palay in Albay and Catanduanes. Meanwhile in Camarines Norte, insufficient moisture available hindered any farming activity related to planting wet season corn. Standing dry season corn in the area might have also suffered from moisture stress.
REGION VI (Western Visayas) Inadequate rainfall received during the month hampered any farming all activities throughout the region.
REGION VII (Central Visayas) Insufficient moisture available during the month hampered all farming activities related to planting rice and corn across the region.
REGION VIII (Eastern Visayas) Land preparation, planting and transplanting activities for planting upland 1st palay and wet season corn had just started in Catbalogan and lowland 1st palay in Catarman. It is because of sufficient moisture available in the area, while in Tacloban, farming activities are hindered by inadequate rainfall received.
REGION IX (Zamboanga Peninsula) Insufficient moisture available across the region made it impossible to undertake any farming activity related to planting rice and corn during the month.
REGION X (Northern Mindanao) Due to adequate moisture available during the month, land preparation, planting and transplanting activities for upland 1st palay as well as wet season corn had just begun in Bukidnon. On the other hand, in Misamis Oriental, all farming activity related to planting rice and corn may be hampered due to the minimal rainfall amount received.
REGION XI (Davao Region) The ample amount of rainfall received during the month favors land preparation, planting and transplanting activities for planting wet season corn, as well as upland 1st palay, across the region.
REGION XII (SOCCSKSARGEN) Due to very low rainfall received in all parts of the region, the planting of rice and corn is hampered.
REGION XIII (CARAGA Region) Sufficient moisture available during the month favors land preparation, planting and transplanting activities for wet season corn as well as lowland 1st palay in Surigao del Sur, while in Surigao del Norte, planting of rice and corn might be hampered because of lesser amount of rainfall received in the area. Likewise, the standing dry season corn in Surigao del Sur is faring well, while in Surigao del Norte, corn crops suffered moisture stress.
ARMM (Autonomous Region of Muslim Mindanao) During the month, land preparation, planting and transplanting activities was favored by the ample amount of rainfall received across the region.
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/ [email protected]
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STATIONS MAY JUNE JULY AUGUST
YMI %
RANK YMI %
RANK YMI %
RANK YMI %
RANK
Region IV-A (CALABARZON)
Infanta 328 90
Region V (Bicol Reg.)
Daet 119 63
Legaspi 244 90
Virac 193 78
Region VIII (Eastern Visayas)
Catarman 394 100
Region XIII (CARAGA)
Hinatuan 278 73
Surigao 98 58
STATIONS APRIL MAY JUNE
YMI %RANK YMI %RANK YMI %RANK
Region IV-A (CALABARZON)
Infanta 85 45 490 85 Region V (Bicol Reg.)
Daet 93 72 264 67 Legaspi 49 23 350 78 Virac 126 83 286 67
Region VIII (Eastern Visayas)
Catarman 36 25 519 95 Region XIII (CARAGA)
Hinatuan 250 67 593 77 Surigao 160 70 282 60
TABLE 1.0 CUMULATIVE YIELD MOISTURE INDICES FOR
DRY SEASON CORN in Millimeters and Percentile Rank.
(April – June 2020)
TABLE 2.0 CUMULATIVE YIELD MOISTURE INDICES FOR
LOWLAND FIRST PALAY in Millimeters and Percentile Rank.
(May - August 2020)
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STATIONS MAY JUNE JULY AUGUST
YMI
% RANK
YMI
% RANK
YMI
% RANK
YMI
% RANK
CAR (Cordillera Autonomous Reg.)
Baguio 244 28
Region I (Ilocos Reg.)
Dagupan 66 10
Vigan 103 30
Laoag 128 30
Region II (Cagayan Valley)
Aparri 56 18
Basco 178 47
Tuguegarao 260 68
Region III (Central Luzon)
Iba 113 28
Cabanatuan 181 48
Baler 46 5
Casiguran 356 63
Region IV-A (CALABARZON)
Tayabas 166 50
Region IV-B (MIMAROPA)
Calapan 58 15
Romblon 123 43
Region V (Bicol Reg.)
Masbate 116 50
Region VI (Western Visayas)
Roxas 111 40
Region VII (Central Visayas)
Cebu 31 22
Dumaguete 115 55
Tagbilaran 58 30
Region VIII (Eastern Visayas)
Catbalogan 157 48
Tacloban 101 32
Region IX (Western Mindanao)
Dipolog 131 42
Zamboanga 111 62
Region X (Northern Mindanao)
Malaybalay 149 20
Lumbia 100 40
Region XI (Davao Reg.)
Davao 130 28
Region XII (SOCSARGEN)
General Santos 33 17
ARMM (Autonomous reg. of Muslim Mindanao)
Cotobato 131 25
TABLE 3.0 CUMULATIVE YIELD MOISTURE INDICES FOR
UPLAND PALAY in Millimeters and Percentile Rank.
(May - August 2020)
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STATIONS MAY JUNE JULY
CAR (Cordillera Autonomous
Reg.)
Baguio 187 47
Region I (Ilocos Reg.)
Dagupan 51 10
Laoag 98 52
Vigan 79 50
Region II (Cagayan Valley)
Aparri 42 32
Basco 136 70
Tuguegarao 199 98
Region III (Central Luzon)
Iba 86 40
Cabanatuan 138 75
Baler 247 80
Casiguran 272 90
Region IV-A (CALABARZON)
Tayabas 127 55
Region IV-B (MIMAROPA)
Calapan 45 22
Romblon 94 63
Region V (Bicol Reg.)
Masbate 89 67
Region VI (Western Visayas)
Roxas 85 60
Region VII (Central Visayas)
Cebu 24 27
Dumaguete 88 83
Tagbilaran 45 43 Region VIII (Eastern Visayas)
Catbalogan 120 68
Tacloban 77 47
Region IX (Western Mindanao)
Dipolog 40 17
Zamboanga 85 80
Region X (Northern Mindanao)
Lumbia 76 43
Malaybalay 114 28
Region XI (Davao Reg.)
Davao 99 37
Region XII (SOCSARGEN)
General Santos 26 25
TABLE 4.0 CUMULATIVE YIELD MOISTURE INDICES FOR
WET SEASON CORN in Millimeters and Percentile Rank.
(May - July 2020)
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TABLE 5.0 DECADAL AND CUMULATIVE DECADAL RAINFALL
For the month of MAY 2020
[actual values (in mm) and percent of normal]
REGION DECADE ACTUAL
MAY
% Normal
of Actual
CUMULATIVE
JAN.-MAY
% Normal
Cumulative
R01
Ilocos Region
13 14 54 75.5 72
14 68 94 143.7 81
15 73 58 217.0 71
CAR
CAR
13 14 48 105.8 62
14 86 124 192.1 80
15 133 124 325.2 94
R02
Cagayan Valley
13 20 50 282.8 69
14 161 230 444.1 92
15 116 136 560.4 99
R03
Central Luzon
13 45 123 214.2 77
14 136 157 350.4 96
15 31 26 381.0 79
R04-A
CALABARZON
13 27 85 318.4 69
14 116 216 434.5 85
15 37 48 471.1 80
R04-B
MIMAROPA
13 13 63 71.0 51
14 94 170 164.5 85
15 37 48 201.7 74
NCR
NCR
13 39 206 139.4 109
14 122 246 261.7 147
15 38 45 300.0 114
R05
Bicol Region
13 51 152 471.6 67
14 139 237 610.8 80
15 9 19 619.8 77
R06
Western Visayas
13 4 20 135.8 61
14 20 53 156.0 60
15 69 127 225.4 72
R07
Central Visayas
13 18 108 328.5 108
14 15 50 343.2 103
15 46 132 389.7 106
R08
Eastern Visayas
13 71 216 773.7 92
14 112 213 885.9 99
15 27 65 913.0 97
R09
Zamboanga Peninsula
13 8 21 172.9 52
14 39 82 212.1 56
15 55 107 267.0 62
R10
Northern Mindanao
13 21 51 245.2 54
14 52 81 297.4 58
15 56 83 352.9 61
R11
Davao Region
13 53 107 566.3 77
14 74 116 640.1 80
15 38 64 678.1 79
R12
SOCCSKSARGEN
13 14 39 164.5 51
14 45 75 209.5 55
15 40 77 249.4 58
CARAGA
13 54 98 1015.9 78
14 49 85 1064.7 79
15 62 109 1126.4 80
ARMM
13 13 34 148.0 51
14 49 77 196.9 56
15 58 102 255.1 62
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FIG. 1.0 ACTUAL CUMULATIVE RAINFALL DURING THE
PASSAGE OF TROPICAL CYCLONE IN THE PHIL.
FOR THE MONTH OF MAY 2020
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A. Decade 1 - MAY 01-10, 2020
B. Decade 2 - MAY 11-20, 2020
B. Decade 2 – JULY 11-20, 2018
C. Decade 3 - MAY 21-31, 2020
FIG. 2.0 TEN DAYS ACTUAL RAINFALL DISTRIBUTION IN THE PHILIPPINES for the month of MAY 2020
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A. Normal Rainfall (mm)
C. Percent of Normal Rainfall ( % )
B. Actual Rainfall (mm)
FIG. 3.0 RAINFALL IN THE PHILIPPINES for the month of MAY 2020
MAY 2020
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Fig. 4.0 Comparison of normal rainfall and potential evapotranspiration
with the actual monthly rainfall at Laoag, Basco, Baguio, Aparri,
Dagupan, and Tuguegarao.
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Aparri
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Laoag
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Fig 4a. Comparison of normal rainfall and potential evapotranspiration
with the actual monthly rainfall at Iba, Ambulong, Muñoz, Port Area,
Calapan, and Science Garden.
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Iba
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Ambulong
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Muñoz
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S. Garden
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Fig. 4b. Comparison of normal rainfall and potential evapotranspiration
with the actual monthly rainfall at Daet, Casiguran, Infanta,
Legaspi, Alabat, and Puerto Princesa.
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Daet
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Casiguran
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Infanta
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Fig. 4c. Comparison of normal rainfall and potential evapotranspiration with
the actual monthly rainfall at Cuyo, Masbate, Mactan, Tacloban,
Catarman and Dumaguete.
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Fig 4d. Comparison of normal rainfall and potential evapotranspiration with the
actual monthly rainfall at Davao, General Santos, Zamboanga, Cagayan
de Oro, and Dipolog.