Multi-objective Planning And Decision Preference Analysis Of Restoration And Reuse Of A Contaminated Site In Northern Guangdong

Land resources are the important foundation of sustainable economic and social development.At present,there are a series of problems in China,such as declining quality of land resources,increasing number of heavy metal contaminated sites,and pollution left after the closure and conversion of industrial enterprises.The secondary development and utilization of the contaminated site can achieve the purpose of revitalizing the stock land,realizing the rational utilization of the spatial layout of the plot and improving the efficiency of land use.However,the pollution risk is still not considered in the current site redevelopment process.According to the above problem,this paper coupled environmental restoration and urban and rural planning related knowledge,for in some heavy metal pollution,recycle suitability evaluation model was constructed and calculated under different schemes of brownfield reuse suitability index,remediation technology for contaminated sites at the recommendations and land utilization way,and based on the above research,on the selected block scene design,A multi-objective planning model was established to solve the land use planning scheme with both economic and environmental benefits,and to explore the influence of decision makers’ different preferences on economic and environmental benefits and land use planning methods.The research conclusions are as follows:（1）By issuing questionnaires to 20 experts and collecting data,the weight of each indicator of the site reuse evaluation index system is calculated by using the analytic hierarchy Process supported by yaanp software.Weight of criterion layer:natural factor（0.35）,economic benefit（0.27）,environmental factor（0.25）,social factor（0.13）;Index layer weight:slope（0.55）,groundwater depth（0.45）,remediation technology cost（0.31）,remediation cycle（0.69）,pollutant removal efficiency（0.35）,carcinogenic health risk（0.45）,non-carcinogenic health risk（0.20）,social acceptability（0.66）,land compatibility（0.34）.The suitability index of different schemes was calculated by using the multi-factor comprehensive evaluation method.The results show that the site is suitable for chemical reduction+solidification stabilization restoration and development as commercial land.Results:The suitability index was 56.63 for residential land use,57.64 for commercial land use,and 55.87 for residential land use.The suitability index of residential land use was 69.15,commercial land use was 72.37,and public land use was 70.61.The suitability index of residential land,commercial land and public land was 64.67,65.71 and 63.94,respectively.It is recommended to use restoration+stabilization to restore the site and plan it for commercial use.（2）When the maximum economic benefit is taken as the goal,the residential land area is 13.5 hm2,the commercial land area is 9.45 hm2,and the public land area is 4.05 hm2,the economic benefit is the largest,372,775,500 yuan,and the ecological benefit is the smallest,119,300 yuan.When the maximum environmental benefit is taken as the goal,the residential land area is 14.85 hm2,the commercial land area is 5.4 hm2,and the public land area is 6.75 hm2.In this case,the economic benefit is the minimum,which is 293,874,800 yuan,and the ecological benefit is the maximum,which is 125,700 yuan.When comprehensively considering economic benefits and environmental benefits,using fuzzy multi-objective programming method,the residential land area is 14.25 hm2,the commercial land area is 7.25 hm2,and the public land area is 5.5 hm2.At this time,the economic benefits are 32.99488 million yuan,and the environmental benefits are 122,800 yuan.Relative to the maximization of economic benefit and environmental benefit,when considering the two kinds of benefits comprehensively,the size of all kinds of land use area under the land use mode is between the first two kinds of land use area.（3）When decision makers prefer economic benefits,they should reduce the area of public land and increase the area of commercial land,while residential land needs to weigh and judge.To maintain economic benefits and give consideration to environmental benefits,they should appropriately reduce the area of commercial land and increase the area of public land,and flexibly regulate the area of residential land.When decision makers prefer environmental benefits,they should increase the area of public land and reduce the area of commercial land,while residential land still needs to weigh and judge.To maintain environmental benefits and give consideration to economic benefits,it is necessary to appropriately reduce the area of public land,increase the area of commercial land,and flexibly regulate the area of residential land.With the increase of policy makers’ preference for environmental benefits,the total economic benefits gradually decreased and the total environmental benefits gradually increased.