A Research of Monitoring Grassland Degradation Based on Mono Temporal MODIS Data

A method of monitoring grassland degradation based on mono temporal MODIS data was proposed.The method took the relative percentage of reduced net primary productivity(NPP),which could be calculated by actual NPP and potential NPP,as the main monitoring indicator.Then how to retrieve actual NPP from MODIS data was introduced briefly.And a method of determination of potential NPP by actual NPP and grassland type distribution map was also proposed.Finally the monitoring method was applied to analyze the spatial characteristics of grassland degradation in north China in 2003.The results showed that: 1) the grassland degradation in north China is very serious;2) spatial variation of the degradation is very obvious;3) the degradation degree is closely related to grassland types.