Monitoring surface water areas of QLW with remote sensing data

Qinghai Lake Watershed(QLW) is a relatively complete inland basin. Here waters play a decisive role for controlling and regulating function of ecological environment. And to describe the change of the water resources, the surface area of surface water is more intuitive than the level and volume. Based on the interpretation of results with middle and high resolution remote sensing data, the study has analysed the characteristics of the changes of surface water areas since 2000 and the relationship between precipitation, temperature, and the areas of melted glaciers and permanent snow. The study shows that: the water resources of QLW have been increasing during 2000 to 2011. The area and the volume of Qinghai Lake (QL) is first decreased and then increased, reaching a minimum value in 2005. The two values have recovered to 2000´s levels, and there is an increase now. Under the favorable water conditions, increased precipitation and the area of melted glaciers and permanent snow, the areas of the little lakes around QL and the rivers in the QLW still showed a declining trend. Maybe the disturbance of human activities is one of the main factors leading to the decrease of water resources.