The Application of Modified Perpendicular Drought Index (MPDI) Method in Drought Remote Sensing Monitoring

Soil moisture and vegetation growth are the most important and direct index for drought. The interpreting to vegetation and spectrum analysis of soil are two important elements in the judgment of drought. Recently, Abduwasit Ghulam and other researchers, oil the basis of the spatial distribution characters of soil moisture in near infrared spectrum, adopt the expansion analysis method and establish PDI. Later, vegetation index is introduced by establishing a new drought monitoring method MPDI after comprehensively considering about the soil moisture and vegetation growth characters. The article, directing against the drought in different periods of Henan province, adopts the MODIS image data to undertake PDI and MPDI calculations and compares with the soil moisture data with that of the same period, concluding that: PDI and MPDI are closely related with the original data from land observation, among which the relations between MPDI and 0-20cm calculation is the closest; PDI and MPDI are all close to the drought situation concluded from the calculation of bared land and the early growth period of vegetations; MPDI is more suitable for the areas with vegetations.