Changes Of Large Lake Wetland Area And Its Ecological Effect Research In Inner Mongolia

Lake wetland, as one of the typical wetland ecosystems on earth, has played a significant role in storing, flood controlling, water conservation, aquaculture, regulating water and maintaining regional ecological balance. However, most lake wetlands in Inner Mongolia has been experiencing a growing shrink on surface area. Therefore, it is of great significance for the effective use of water resources in lake wetland to grasp the dynamic process of lakes’variation timely and accurately in Inner Mongolia. Six typical lake wetlands in Inner Mongolia have been picked as the research objects in this paper, which are Hulun Lake and Dalinur Lake in the east; Chagannur Lake and Dai Lake in the middle; Bojiang Lake and East Juyan Lake in the west. With a series of Landsat satellite data as the main data sources, I extracted the surface area of the 6 lakes from 24 remote sensing images of the 6 lakes in 1990,2000,2007 and 2011, by water index method. Water index method is used to extract the lakes water area, and analyze the characteristic of lakes water area’s variation from the temporal and spatial scales. In addition, this study adopts the temperature and precipitation data of 13 meteorological stations in Inner Mongolia, as well as the lakes’types of land data in 1980,1995 and 2000, this thesis also analyzed the driver of surface area changing for each lake. Finally, this paper explores the ecological effect caused by the change of lake wetland water area. Main conclusions of this research are as below:(1) During 1990-2011, all the 6 lake wetlands researched experienced a shrink on surface area; which the shrink of Bojiang Lake is the most significant, and the Dai Lake takes the second place. The other four lakes area changes are relatively slow.(2) Six typical lakes water area of Inner Mongolia show certain regularity in the space change, and the eastern lakes atrophy is oriented the south and east direction; central lakes atrophy is dominant in southwest; in western region, it hasn’t showed obvious regularity due to the differences between two lakes atrophy.(3)Temperature and precipitation have great effects on the changes of the eastern and central lakes area, and the effect of temperature is more obvious than precipitation’s.(4)With the shrinking of lake water areas, vegetation in most researched area showed a decreasing trend. In addition to the Hulun Lake, the others middle and high vegetation coverage area showed a decreasing trend; the alkaline land and sand area had kept growing.