Climate Change Impacts on Wetlands of the Yellow River Headwaters

摘要

The impacts of climate change and human activities have modified the structure and the distribution patternof wetlands of the Yellow River headwaters. We studied ETM and TM satellite images data using GIS from1990, 2000 and 2010 to analyse changes in the spatial distribution and patterns of the wetland area thatsupplies water to the Yellow River. We propose stable conditions for the different types of wetlands andmutual transition probabilities. Time series data on temperature, precipitation and evaporation at the Jimaiand Maduo hydrological and meteorological stations were analysed. Characteristics and trends ofmeteorological factors were studied. The relational grades of different wetlands and meteorological factorswere calculated using Grey System Theory. Major factors determining wetland evolution in the Yellow Riverheadwaters were proposed and the impacts of climate change on wetland evolution were analysed. Wetlandevolution in the Yellow River headwaters is closely related to climate change. Precipitation is the dominantmeteorological determinant for the wetland pattern evolution and transformation of the other wetland types.Presence of wetland areas is positively correlated with precipitation and temperature and negatively correlatedwith evaporation. Wetlands are important for maintaining the “cold and wet” effect on regional climates;when precipitation increases, the “cold and wet” effect of the wetland increases.