Optimal Allocation Of Land Resources Based On Ecosystem Services

Ecosystem services namely benefits that human gained from the ecosystem.It is crucial for human existence and development.Due to the human activities and rapid urban expansion,a large number of natural land were converted to developed land(such as urban construction land and cropland),which has negative impacts on ecosystem services over time.Land use change has direct impact on ecosystem services.Ecosystem services analysis is beneficial for land management and decisions.In this study,based on land use change simulation and ecosystem services assessment,creatively bring Modern Portfolio Theory into risk management of land use decisions.Using Changsha as an example,we establish two investment optimization models to optimize investment in land for ecological conservation and for urban expansion.Firstly,based on land use change of Changsha from 2000 to 2010,we adopt CA-Markov model to predict land use change under different land use scenarios in 2025.Secondly,Changsha is divided into four regions according to the administrative divisions,including Changsha town,Ningxiang County,Liuyang City and Changsha County.We evaluate ecosystem services values(ESV)and the loss of ecosystem services values due to urban expansion(ESVloss)under three scenarios in four regions of Changsha.The calculational results can provide basic data for optimization models.Finally,we construct risk management framework of land use decisions to optimize allocation of land resources based on ESV evaluation.(1)On the basis of Modern Portfolio Theory,in order to improve ESV of land in rapid urban development,we establish investment optimization model to optimize investment in land for ecological conservation.In this model,regional ESV per unit area(ESV)is regarded as expected return.And uncertainty of land use change is regarded as risk.It can optimize allocation of investment in land to improve ecological benefit.(2)On the basis of Modern Portfolio Theory,in order to improve economic benefits of urban expansion and reduce ecological cost in rapid urban development,we establish investment optimization model to optimize investment in land for urban expansion.In this model,ESVloss,is defined as ecological cost and incorporated into the cost-benefit analysis of urban expansion.The benefit-cost ratio of urban expansion(BCR)is regarded as expected return.And uncertainty of land use change is regarded as risk.It can optimize land allocation for urban expansion in space.The results are as follows:(1)With the development of economy and urbanization,the loss of ESV are inevitable.Integrating ecosystem services into land use decisions is significant for sustainable development and ecological conservation.(2)Based on Modern Portfolio Theory,we raise the risk management framework of land use decisions integrated ESV.It can reveal the optimal spatial allocation of investment to maximize the expected return(ESV or BCR)at a given level of risk or minimize risk at a given level of the expected return(ESV or BCR).(3)Taking risk management of land use decisions in Changsha as an example to optimize allocation of land resources based on ESV evaluation.Investment for ecological conservation should be partial to Liuyang City to get higher ESV.It should also be shifted from Liuyang City to other regions to reduce risk.Investment for urban expansion should be partial to Changsha town to get higher BCR.It should also be shifted from Changsha town to Liuyang City to reduce risk.