Remote sensing monitoring on degraded steppe and determination of reasonable grazing intensity for the restoration of steppe in middle reach of Xilin River Basin

Using Landsat TM CCT, selecting the middle reach of Xilin River Basin as study area, we established model of steppe aboveground biomass estimation, and estimated aboveground biomass of steppe in the study area in middle July, 2000. Based on the scope of aboveground biomass of two main types of steppe vegetation undegraded and degraded, we assessed steppe vegetation degradation rank with the unit of pixel, and compiled steppe degradation distribution map of the middle reach of Xilin River Basin. In 2000, the area of degraded steppe in the east part of Xilin River was 2 697.3 km2, 49.7% of the whole steppe area, the area of degraded steppe in the west part was 1 644.4 km2, 30.3% of the whole steppe area. Considering steppe ecosystem sustainability as final goal, We determined different forage grass utility rate to the different degradation ranks, divided six grazing intensity ranks, calculated reasonable grazing intensity, area and grazing capacity. The result can provide decisionmaking support for the restoration of degraded steppe and animal husbandry sustainable development at the regional level.