Study On Estimation And Spatio-temporal Differentiation Of Land Ecosystem Services Value In Coastal Saline-alkali Soil Area

In recent years, the research of ecosystem services value becomes a hotspot issues, but a few study refer to coastal saline-alkali soil area. The coastal region belongs to an ecological sensitive zone, study about the coastal land ecosystem service value and its spatial differentiation characteristics, we can grasp the environmental change of the coastal terrestrial ecosystem; It has the scientific guiding significance for planning policy about local sustainable development. This paper is based on the relevant research results at home and abroad, uses the TM / ETM + data and MODIS NDVI data as the main data source to build an evaluation system, ecological parameters evaluation model and value evaluation mode of typical coastal terrestrial ecosystem, takes Huanghua City as study area, which is located in the coastal plains, respectively evaluates the value of ecosystem services in Huanghua City in 1990, 2000 and 2011, then analyzed and compared the temporal and spatial changes in Huanghua City and finally presents regulation measures about land use based on the ecological protection. The result shows that:(1) Combined with the characteristics of ecological environment in coastal areas,the land use types are divided into nine categories, which are farmland, garden, grassland, wetland, construction land, water, saline-alkali land, saltern and other land. Divided the coastal saline-alkali soil area land ecosystem service into eight ecological system function indicators as the components of assessment, included nutrient recycling, water conservation, entertainment and culture, material production, biodiversity, gas regulation, climate regulation, environment purification. On the basis of using the light use efficiency model(CASA) calculate the ecological parameters(NPP), established the assessment indexes system and develops economic value assessment using different methods, included cost analysis method, shadow engineering method, survey method and market price method.(2) The characteristic of the total quantity: the value of ecosystem service in Huanghua City in 1990, 2000 and 2011 is respectively 10799 million Yuan, 10096 million Yuan and 9567 million Yuan; According to land use types, farmland provides the maximum contribution, which accounts for 36% of the total ecosystem services value; In terms of the structure, the value of nutrient recycling services provides the maximum contribution, which accounts for 30% of the total ecosystem services value; The value of environmental purification services provides the minimum contribution, which only accounts for 0.17% of the total ecosystem services value.(3) The characteristic of Spatio-temporal differentiation: According to the view of the total quantity, the value of ecosystem services has decreased by 1232 million Yuan in Huanghua City during 1990-2011; According to land use types, in the period of 1990-2011, the value of ecosystem services of farmland land and saline-alkali soil land show a large change, respectively reduced 993 million Yuan and 485 million Yuan; In terms of the structure, the value of the entertainment and culture services and the climate regulation services show a large change, the value of the environment purification services and the biodiversity services range a small change; According to the view of spatial variation of the total quantity, the value of ecosystem services changes severely in the central and western region but moderately in the eastern coastal region in Huanghua City during 1990-2011,which shows a trend that the center of the total ecological value moves south-west ward and has shifted 816.7m during 1990-2011; According to the administrative regions, the Huanghua Town located around the downtown changes the most sharply while Nanpaihe Town located in the eastern coastal regions changes the most gently.(4) According to land use type changes, calculate the value of ecosystem services and losses flow matrix, obtained as a result that the reason of the decrease value of ecosystem services is the occupation of construction land and the loss of wetland, the reason of the increase value of ecosystem services is transfer into farmland. The value of ecosystem services in Huanghua City shows a significant negative correlation with GDP. Therefore, the ecological environment should be the supervised and protected more strongly in the development of the economy and the population should be kept within a reasonable range.