Study On The Ecological Profit And Loss Of Requisition-Compensation Balance Of Cultivated Land Of Qinghai Province

Qinghai Province is located in the northeast of Qinghai-Tibet Plateau,which is known as “the third pole”.It is the most important ecological security barrier and water conservation area of China,and it is also a typical ecologically fragile area and sensitive area to climate change.Due to the implementation of the great western development strategy and the requirements for completing the building of a moderately prosperous society in all respects,the social and economic development of Qinghai is going to occupy cultivated land inevitably.Requisition-compensation balance of cultivated land is a basic cultivated land protection policy,and the balance in quantity,quality and ecology has more important practical significance in Qinghai.Therefore,it is typical and representative to study the impact on ecological environment of the implementation of the policy in Qinghai.And it has important reference significance for the construction of ecological civilization in China under the new situation.With the help of multi-source data,CASA model,InVEST model,RS and GIS,to analysis the characteristics of the requisition-compensation balance in Qinghai Province.This paper evaluates the value of ecosystem services of the relevant land-use type by integrating various methods basing on the theories of ecosystem services.Then it analyzes the dynamic change of the ecological value of cultivated land in Qinghai during the implementation of the balance policy.The research includes three aspects:(1)Analyzing the characteristics of temporal and spatial changes of cultivated land and situation of the requisition-compensation balance of cultivated Land in Qinghai;(2)Assessing the value of ecosystem service of typical land-use type of Qinghai;(3)Qualitatively and quantitatively analyzing the ecological profit and loss of the requisition-compensation balance in Qinghai Province.The results show that:(1)Grassland is the main land use type in Qinghai Province,and the area of cultivated land is small,which is mainly distributed in the eastern agricultural area.The decrease of cultivated land was mainly in Haidong,Xining and Hainan,while the increase of cultivated land was mainly in Hainan,Haibei,Haidong,Xining and Haixi.The amount of supplementary cultivated land in the whole province is far more than the occupied cultivated land.The largest amount of supplementary cultivated land is in Xining and Haidong,while the largest amount of supplementary cultivated land is in Haixi and Haibei.The spatial distribution regularities of the occupied and supplementary cultivated land are quite different.(2)The total value of ecosystem services provided by different land use types per unit area in Qinghai was in the order of forestland > wetland > farmland > grassland >desert > salt-alkali land.The total value of ecosystem services in Qinghai showed a trend of gradually increasing from northwest to southeast.In terms of time,the total value of ecosystem services in Qinghai Province showed a trend of decreased first and then increased,but it is increased overall.(3)Qualitatively,the occupied cultivated land in Qinghai is mainly located in Xining and Haidong with the highest ecological value,however the supplementary cultivated land is mainly located in Haixi with lower ecological value.There is an ecological imbalance in the process the requisition-compensation balance of cultivated land.Quantitatively,the ecological value of each unit area of cultivated land occupied and compensated will lose 30,500 yuan in Qinghai Province,and the total loss of ecological value caused by the requisition-compensation balance of cultivated land will exceed 2 million yuan from2005 to 2018.The requisition-compensation balance of cultivated land has not realized the ecological balance.