Vol. 7, No. 1, 81-91, 2008

Abstract
Droughts are normal recurring climatic phenomena that vary in space, time, and intensity. The spatial and temporal variability and multiple impacts of droughts provide challenges for mapping and monitoring on regional scales. With the launch of new generation sensors such as Moderate Resolution Imaging Spectroradiometer (MODIS), the monitoring of aberrant climatic events may be explored in an efficient way. An empirical method called Temperature Vegetation Dryness Index (TVDI) was used for drought monitoring in two different countries. In this paper we demonstrate the usefulness of the TVDI approach and of MODIS products for the identification of drought conditions in affected states of India and the Philippines. The satellite derived results reveal that they can detect and monitor the drought accurately. The results were compared with the crop yield for validation of remotely sensed measurements for drought detection. In Gujarat state, the drought years showed a negative yield anomaly as compared to a normal year. The average yield anomaly in 2002 was -11.2 and -35.49 for food grains and oil seeds respectively. This indicates the influence of drought on yields to a greater extent. But in 2003, it gives a positive yield anomaly and indicates no drought effect on crop yields. In Iloilo province, the results revealed that the rice area and the production reduced due to the drought in 2000 as compared to other normal years. Overall, the results imply that the satellite derived drought index (TVDI) is a useful tool for the identification of drought affected areas in real time using satellite measurements.

ISSN 1729-3782