Changes and Driving Factors of Plateau Wetlands in Maduo County
Wetland is a unique and important ecosystem with significant environmental function and ecological benefits on the surface of the earth. In recent years, wetlands have become one of the important worldwide concerned research fields. Owning the world' s unique large-area alpine wetland, the source regions of Three Rivers is the ecological barriers of ecological environmental security and regional sustainable development for the middle and lower reaches of rivers in China and Southeast Asian countries. Located in the core area of the Sanjiangyuan National Nature Reserve, Maduo County is the key area of regional ecological environment construction and control. The research results of this study can provide a reference to the wetland protection of the source regions of Three Rivers. The main data sources used in this paper were Landsat TM images around 1990, Landsat ETM+ images around 2000 and HJ-1 satellite images around 2010 of Maduo county, the source regions of Three Rivers, Qinghai province, as well as other assistant data such as DEM, topographic maps and statistical data and so on. Referencing to the Wetland Convention and wetland classification system in China,considering the actual situation of Maduo County, the wetland classification system of Maduo County was established, in which the wetlands of Maduo County were divided into two major categories, inland natural wetland and artificial wetland. The natural wetlands include river, lake, swamp, flood plain. The artificial wetland was reservoir. According to the established wetland classification system of Maduo County, the information of the wetlands was extracted by artificial visual interpretation and then the wetland distribution maps of Maduo County in 3 periods were made respectively, which were used to evaluate the wetland area changes of Maduo County during the past 20 years. Change detection was made to raster images converted from the interpretation results to get the conversion matrixes of various wetland types during the two periods, and then analyzed the conversion matrixes to evaluate the dynamic changes of wetlands in Maduo County. Combining with meteorological data and statistical data, the reasons for the wetland dynamic changes of Maduo County during the past 20 years were preliminary approached. The results indicated that the total areas of wetlands in Maduo County in 3 periods were 3 460.250 km2, 3 158.223 km2, 3 398.597 km2. The total wetland area of Maduo County decreased firstly and then increased. During the first decade, the change of swamp area was the greatest, followed by that of lake and river, while the change of lake area was the greatest during the second decade, followed by swamp and river. The natural factors affected the change of wetlands of Maduo County, including temperature, rainfall and overgrazing, development of tourism and the implement of the Sanjiangyuan ecological protection projects.
wetland extractionremote sensingchangeMaduo County
NETL
NSTL
万方数据
维普
