Research Of Ecological Safety Based On Water Environment And Landscape Pattern In Ningxia Shahu Lake

Ecological security is currently one of the hot spots in ecology.Shahu Lake in Ningxia,which is a typical combination of desert and wetland areas,is a typical wetland ecosystem in temperate grassland to desert area, is the natural protection area of Ningxia, is the important source of biological resources "reservoir".Shahu Lake in science, ecology, biology has very important significance.However, Shahu Lake is in the arid and semi-arid area of our country, the evaporation is strong, the precipitation is insufficient, and its ecosystem is extremely unstable.Therefore, the research of ecological security in Shahu Lake has a certain representative significance.Water environment is the foundation of Shahu Lake ecological security, landscape pattern change is the direct reaction of ecological processes.Therefore, this paper learned the change trend of water environment and landscape pattern change in Shahu Lake.On the basis of Shahu Lake water environment in 2002-2014 and 2002,2006,2010 and 2014 four period Shahu Lake landscape pattern data, combined with the high intensity of human disturbance data and Shahu Lake take measures to protect the ecological environment. The model of "pressure-state-response" was used to build security evaluation index system. AHP to determine the weight of each index.The change of Shahu Lake ecological security situation was analysesd, and put forward Shahu Lake ecological protection countermeasures. In this paper, the main research results are as follows:(1) Perennial water of Shahu Lake level is maintained between 1098.95-1099.15m, the water level change is small, the water level fluctuation is mainly affected by the water supply and evaporation.The main pollutant of Shahu Lake is TP、TN、NH3-N、 BOD、COD5、petroleum. In main pollutants TP pollution is seriously exceed the standard, and main pollutants exceed the standard more in high water period than normal water period.(2) Tourism District, water and marsh area gradually expanded, farmland, sand land in the shrinking year by yea in Shahu Lake during in 2002-2014.From the landscape pattern index, farmland, construction land and other types of landscape patch number and the whole area of wetland increased year by year in Shahu Lake.(3) The value of the ecological security in Shahu Lake is 2006>2014>2010>2002.In 2006,Shahu Lake’s ecological security was the highest, and the lowest level of ecological security in Shahu Lake was in 2010. Shahu Lake ecological security level from comparative safety status to early warning status.The main influencing factors of Shahu Lake ecological security for pressure (P) and response (R) layer index, We need to control the ecological pressure in Shahu Lake from the stress level and response level indicators in Shahu Lake, improve the ecological security of Shahu Lake.