Dynamic Succession Characteristics Of Wetland And Ecological Services Value Of Dynamic Assessment In The Middle Heihe River

The Middle Heihe River wetland is located in inland arid region of Northwest China,which is a multi-type and multi-level complex natural formation ecological system, which is one of the three western route of migratory birds in China, meanwhile, which is one of 8article migratory birds migration channel transfer station by East Asia-India in the world.More importantly, the Middle Heihe River wetland is natural ecological barrier, which is to prevent the connection of Badain Jaran desert and Tengger Desert, and play an important role in the ecological balance. Due to the influence of natural factors and human activities, the Middle Heihe River wetland's area is reducing; its fragmentation is more and more serious.The ecosystem is degenerating. Dynamic assess the change of wetland landscape and the wetland ecosystem service value have useful and vital practical significance, that is good for protecting wetland limited resources and maintaining biodiversity and ecological security in Heihe River.In this paper, using RS and GIS techniques for 1975, 1987, 1992, 2001 and 2010 Middle Heihe River Wetland Landscape Pattern Changes were analyzed; dynamic evaluation of the 1992, 2001 and 2010, three times ecosystem service functions and ecological security system, and finally qualitative analysis of seven factors likely to affect the driver of ecosystem services value changes, hoping to provide basic data and decision-making basis for sustainable development and environmental protection in Heihe. The results showed that:(1)in five period, River Wetland, Lake Wetland and Reservoir pond Wetland's area is reduced trend in 1975-1992, its increased trend is 1992-2010. Floodplain wetland and Marsh wetland's area is always reduced trend in five period. The area of transfers to non-wetland of wetlands is greater than the non-transfer of the wetland to the wetlands. The percentage of Reservoir pond wetland's area is on the rise, Lake Wetland and Reservoir pond Wetland's area is decline in the total wetland.(2)The ecological service value of Middle Heihe River wetland are 50.8428 million Yuan, 45.1365 million Yuan and 41.6102 million Yuan in 1992,2001 and 2010; All of the wetlands area are reduced. The rate of Reservoir pond wetland's ecological service value is on the rise, and the percentage of River Wetland, Lake Wetland in the fall. The values are on the decline of different function of ecosystem services. The percentage of hydrological regulation functions, maintaining nutrient cycles functions,maintaining biodiversity functions and aesthetics landscape functions are on the rise, else arein decline. The population growth trend of the human factor and human interference factor and ecosystem service function value is consistent with the trend.(3) The assessment of ecological security are serious warning, moderate warning and moderate warning in 1992,2001 and 2010. Population density and human disturbance index has increased year by year.The wetland fragmentation index and plaque degradation is increasing in the yearly.