Application of Perpendicular Drought Index in the Drought Assessment: A Case Study in Ningxia Huizu Autonomous Region of China Using MODIS Data

In this paper, 1) atmospheric correction for nir and red channels of remote sensing imagery is carried out by 6S code, and nir-red spectral reflectance space is obtained using atmospheric and geometric corrected MODIS data; 2) perpendicular drought index (PDI) is calculated using MODIS data on the basis of the distribution characteristics of soil moisture in the nir-red spectral reflectance space; 3) sensitivity analysis and accuracy assessment of results contributed from upscaling of the PDI model to MODIS 500m spatial resolution is conducted; 4)finally, quantitative evaluation of drought condition of Ningxia, Northwestern China is carried out with PDI. Results show that satellite estimated drought values by PDI indicate significant negative correlation with 0 similar to 20cm averaged soil moisture obtained over the whole study area. Highest correlation is R(2)=0.53. It is evident from the results showing the spatial distribution of drought in. the Northwestern China that remote estimated drought information is highly accordant with field drought status.Geosciences, MultidisciplinaryRemote SensingImaging Science & Photographic TechnologyEICPCI-S(ISTP)