Impact Of Urban Expansion On Ecosystem Services In The Three Gorges Reservoir Area In Chongqing

Chongqing Three Gorges Reservoir area is located in the upper reaches of the Yangtze River is the end of the Three Gorges Reservoir area and even the most important lifeline and protect the ecological environment of the Yangtze River Basin,along with the development of city,has important significance of city expansion for ecosystem services.In this paper,2000,2005,2010 and 2015 based on land use data,construction of CA-Markov model based on adding GDP,population,elevation and other limiting factors,through scenarios,simulated 5 different scenarios of construction land evolution,combined with the ecosystem service function,using the InVEST model,the carbon storage?water supply and Soil Conservation Service Simulation Research of Three Gorges reservoir in Chongqing of construction land on the status of ecosystem services and future impact,so as to determine the more suitable for the development of the Three Gorges Reservoir area of Chongqing city expansion mode.The results demonstrate:(1)From 2000 to 2010,the changes of land use great,construction land expansion to 1550.47km~2,farmland and broad-leaved forests as the main contributor,were transformed into 758.93 km~2 and 314.10 km~2,construction land mainly from the western center to the surrounding city expansion;the most obvious expansion is the natural development of the scene,followed by the rapid growth scene of GDP and population,but for the occupation of cultivated land and woodland is serious,aggravated the contradiction between man and land;ecological protection scenario while reducing the amount of transformation of cultivated land and forest land,the ecological environment has been improved,but the ecological red line within the water area increased greatly,is not conducive to people's normal life and production;sustainable development in the context of the growth of construction land a smooth,cultivated land and woodland to be protected at the same time,the water area of growth is reasonable,is the most suitable for simulation of Three Gorges Reservoir area in Chongqing,The development situation of the urbanization process.(2)From 2000 to 2010,the growth of carbon storage grow doubled,general benefited from the land type carbon sequestration capacity;the decline of water supply capacity of the water supply amount and type of water supply ability is reduced,the original water supply increased in western urban areas,decreased in 2005-2010;soil was presented the first increase and then decrease,with the accelerated expansion of the construction,a large number of occupation of arable land and forest,forest area change in the north of greater rainfall erosivity to strengthen the function of soil conservation,serious losses.There are few areas with strong carbon reserves,water supply and soil conservation function,only2.85%of the area of the study area,and the overall ecosystem service function is weak.(3)The growth of construction land has a greater impact on ecosystem services.The capacity of carbon storage and water supply is less than that of other land use types.Therefore,the expansion process leads to a decline in carbon storage,water supply and soil conservation function.Comprehensive effect of natural environment on ecosystem service development,construction land expansion caused by the decrease of ecosystem services are the most serious,impact scenarios and rapid population growth scenarios of ecosystem services rapid GDP growth is continue strong,reduce the amount of carbon sequestration of cultivated land and forest land,the scene of ecological protection and sustainable development of ecological system service capacity is weak,but the ecological protection scenario in water carbon storage abilities of carbon sequestration is reduced,restricting the construction of the Three Gorges Reservoir area of Chongqing water conservancy facilities,and sustainable development in the context of the kind of carbon sequestration capacity and carbon sequestration increased,construction land within the scope of the important functional areas of carbon the reserves of more services,the destruction of the ecological environment in the development of the economy is less,the construction land expansion at the same time,also to maximize the protection of ecological system and the service function is more conducive to the improvement of the ecological environment in the Three Gorges Reservoir area of Chongqing.