Study on Drought-stricken and Drought-damaged farmland in China during 1982-2001 with Remote Sensing

摘要

The water deficit index (WDI) was introduced briefly. And the 10-day WDI images were estimated with the 1982-2001 NOAA AVHRR dataset of NDVI, light temperature of channel 4 and channel 5. Based on the 10-day WDI images, the pixels that represent the drought-stricken and drought-damaged farmland were picked up for every year. Only when WDI greater than 0.75 during crop development (March ～ October) happened in more than one decades, the pixel was thought as drought-stricken. And WDI greater than 0.7 happened in more than two continuous decades, the pixel was treated as drought-damaged. The remotely sensed acreage of drought-stricken and drought-damaged farmland have similar dynamics as the statistical results except in early 1980s. I would like to oppugn the statistical results in early 1980s. Anyway, results showed that remotely sensed WDI is useful in retrieving drought stricken and damaged farmland and it also verified the rationality of WDI in evaluating regional soil water status.