An integrated lake geographical information system on the third pole

Alpine lakes on the Third Pole (TP) have been used as an indicator for knowing hydrologic process, evaluating water resources and understanding climate change. However, the main driving forces and climate-driven mechanisms of lake variations still remain debate. One of a reason that limits these researches is lack of the understanding of the lake hydrological characteristics. In this study, we created a lake inventory on TP, and for the first time, we established a comprehensive hydrological network for each lake mainly based on 246 scenes Landsat series images, 236 Chinese topographic maps, and SRTM DEM. According to the lake's location in the hydrological network, the lakes can be classified as closed lake, upstream lake or outflow lake. The closed lake has only inlet with no outlet. Water in the closed lake does not leave the basin by the surface runoff. The upstream lake has inlet and outlet, and the runoff will finally flow into a closed lake. The outflow lake has inlet and outlet, while the runoff will join into rivers and may eventually join into the ocean. These three kinds of lakes have different drainage modes, so their intensity and forms affected by climate change may not the same. It's necessary to distinguish them and consider them separately. The results show that there are 396 closed lakes, 472 supplying lakes and 312 outflow lakes on TP in 2010, with the area of 35,498.2 km2, 7,301.6km2, and 3,373.6 km2, respectively. Meanwhile, we determined the relationship between lakes and their supplying glaciers. What's more, an integrated lake geographical information system on the third pole has been build. This system realizes the information visualization and mainly includes two functions. If you click any lake, you can know the catchment of this lake, the streams how the runoff inputs a lake, and how a lake is connected to another lake or river. And you also can know if there are glaciers supply the lake or not, and the location and area of these supplying glaciers. If you click any glacier, you can know where the glacier runoff will be flow into eventually. This system can be a crucial basis for the related lake-climate researches on the third pole.