Analysis on the Vegetation Change in Shiqihe River Basin Based on RS Technology

Through standardized processing of 2 series of remote sensing data of Shiqihe river basin in 1991 and 2002,the mixed-pixel model was used to perform the vegetation coverage degree and solve the vegetation coverage change situation in Shiqihe River Basin between 1991 and 2002.The result showed that the total vegetation coverage level of Shiqihe River Basin had a trend of gradually degradation.From 1991 to 2002,total vegetation covering area was reduced from 909.259 to 882.611 km2 in Shiqihe River Basin,decreasing by 19.993 km2 and accounting for 2.19% of the total drainage area.The vegetation coverage level in vegetation covering area also had markedly change,mainly manifesting that in the area of middle vegetation coverage(50%-80%) continue to be decreased and that of low vegetation coverage(30%) continue to be expanded.