FORECASTING AND MONITORING AGRICULTURAL DROUGHT IN THE PHILIPPINES
A monitoring and forecasting sytem is developed to assess the extent and severity of agricultural droughts in the Philippines at various spacial scales and across different time periods. Using Earth observation satellite data, drought index, hazard and vulnerability maps are created. The drought i...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-06-01
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Series: | The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences |
Online Access: | https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLI-B8/1263/2016/isprs-archives-XLI-B8-1263-2016.pdf |
Summary: | A monitoring and forecasting sytem is developed to assess the extent and severity of agricultural droughts in the Philippines at
various spacial scales and across different time periods. Using Earth observation satellite data, drought index, hazard and
vulnerability maps are created. The drought index, called Standardized Vegetation-Temperature Ratio (SVTR), is derived using the
Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST). SVTR is evaluated by correlating its values
with existing agricultural drought index, particulary Evaporative Stress Index (ESI). Moreover, the performance of SVTR in
detecting drought occurrences was assessed for the 2015-2016 drought event. This period is a strong El Niño year and a large portion
of the country was affected by drought at varying degrees, making it a good case study for evaluating drought indices. Satellitederived
SVTR was validated through several field visits and surveys across different major agricultural areas in the country, and was
found to be 73% accurate. The drought hazard and vulnerability maps are produced by utilizing the evapotranspration product of
MODIS, rainfall climatology from the Tropical Rainfall Microwave Mission (TRMM) and ancillary data, including irrigation,
water holding capacity and land use. Finally, we used statistical techniques to determine trends in NDVI and LST and generate a sixmonth
forecast of drought index. Outputs of this study are being assessed by the Philippine Atmospheric, Geophysical and
Astronomical Services Administration (PAGASA) and the Department of Agriculture Bureau of Soils and Water Management (DABSWM)
for future integration in their operations. |
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ISSN: | 1682-1750 2194-9034 |