Monitoring Rangeland Grasshopper Infestation in the Regions around Qinghai Lake by Remote Sensing
环青海湖地区草地蝗虫发生遥感监测方法研究

To develop a remote sensing model for monitoring the spatial distribution of rangeland grasshopper infestation in the regions around Qinghai Lake, 198 site grasshopper density (GD) data, and three TM5 images were collected during the last ten days of June and the first ten days of July in 1997, the middle and last ten days of August in 1999, the middle and last ten days of 2000. Ten vegetable indexes (VI), for example the normalized deviation vegetable index (NDVI) and brown vegetable index (BVI), were calculated from TM5 images. The correlations between the GD and VI were investigated with statistics methods. It shows that though the linear correlation between GD and the ten VI are not significant, GD is sensitive to NDVI and BVI, 86% of high GD samples appear in the span 0.2