Changes of Wuliangsuhai Lake in past 150 years based on 3S technology

According to analyzing the geographical map, image of remote sensing, historical documentations and field research, we find the reason for the formation of Wuliangsuhai Lake is that the Yinshan mountains raised continually due to neotectonic movement in the Cenozoic Quaternary, cause the Yellow River diversion then vegetation deterioration in the grassland, and the quicksand from Alxa region led to the riverbed of north river filled up with mud on the effect of northwestern wind, so the Wuliangsuhai Lake is a River Trace Lake. We made the palinspastic map of location of Yellow River and The shape of Wuliangsuhai Lake at various periods; explained the landsat TM/ETM data from 1986 to 2006 and analyzed the evolvement of lake. Over the past nearly 20 years, the areas of reeds had an increasing trend year after year, the main spread aspect was along the west side of lake and had no trend to spread in lake, the natural reeds increased by about 0.86km² each year on the average and the artificial reeds is about 2.4km², the areas of open water took on fluctuated state.