Land Use Change And Its Influence On Water Conservation Service Based On CLUE In Jiangxi Province

Using CLUE (The Conversion of Land Use and its Effects) model based on GIS spatial analysis and statistics, this thesis introduced three scenarios("Business as Usual","Planned Scenario"and"Optimum Scenario")to simulate the land use spatial change in Jiangxi Province, from 2001 to 2030, then estimated water conservation service change of ecological system based on land use change under three scenarios in Jiangxi Province from 2001 to 2030.The main methods included the followings: (1) Scenarios analysis. Scenarios provided an effective tool to assess the risks of current land use patterns and the policy options, and offer more comprehensive and meaningful scientific information to policy-makers from different approaches by taking into account various influence factors. (2) CLUE model. CLUE model was constructed on the basis of fully understanding the change features in land use system, which allowed the simultaneous modeling of different land use change. (3) water balance method. According to the different types of land use, it provided different runoff coefficient and targeted estimate water conservation services of different land use type.The main research results including the following two aspects:Firstly, the land use change simulation results:(1) under"Business as Usual"scenario, the arable land continue to decline, construction land increase sharply, while forest land area remain stable;(2) under"Planned Scenario"scenario,the arable lands continue to grow, construction land increase slightly and remain unchanged after 2020; forest land area remain little changed, but high-density forest area proportion grow; the area of rivers and lakes decrease marginally; while the area of marshes and peatlands grow greatly;(3) under"Optimum Scenario"scenario, the forest area grow less than that under"Planned Scenario"; while the area of rivers and lakes, marshes and peat lands all increase significantly. The study also suggests that the CLUE Model is very powerful in predicting the future land use change, and the land use changes under different scenarios vary greatly in spatial distribution.Secondly, under three scenarios, different forms of land use causes three different water conservation service trends. (1) BAU, total water conservation service keeps a slow decline. (2)Planning scenario, total water conservation service rise maintain a slow rise again after a rapid rise.(3) Optimization scenario, total water conservation service always maintain a steady increase, service amounts less than planning scenario before 2013, after more than planning scenario, and maintain steady and rapid growth. From the view of the ecological sustainable development, optimize scenario is the best, planning scenario is second, and business as usual scenario is the worst. In addition, high-density forests, rivers and lakes, swamps and peat lands, low density forests and scrubs, and arable land are the main contributors to the total water conservation service in Jiangxi province, while the contribution of water conservation services of building land, low-density grassland and other land use type are so less that should be neglected.In a word, water conservation service change tendency under three scenarios embodies the ecological effects of the existing different land use pattern and the prediction results are expected to help guide the future development and revision of land use planning, as well as sustainable land management in the study area.