Research On Sustainable Allocation Of Agricultural Water And Soil Resources And Virtual Water Trade Under Changing Environment

The conflict between limited water supply and increasing water demand has highlighted the importance of agricultural soil and water resource management.Sustainable development is the core concept of modern agricultural planning,and the sustainable management of agricultural soil and water resources requires the coordinated development of resource,social,ecological,economic and environmental interests,while climate change and socio-economic development increase the complexity of its management.There is a complex relationship between agricultural soil and water resource utilization,regional crop virtual water flow and sustainable agricultural development.Based on this,this paper takes the Heilongjiang area of the Songhua River Basin in China as the research object to optimize the sustainable allocation of agricultural soil and water resources under the changing environment.A"simulation-optimization-evaluation"based dynamic linkage analysis framework for agricultural sustainability was developed to analyze the intrinsic linkage between agricultural system sustainability and agricultural water and soil resource allocation and its response to the changing environment.The analysis of impact factors and sustainability evaluation of virtual water flows based on food trade were also carried out.The main study contents and findings are as follows:(1)Multi-dimensional sustainable regulation of agricultural water and soil resources under climate change and socio-economic development.Atmospheric circulation model and representative concentration pathway scenarios are used to predict future climate,organically coupling climate scenarios and society’s future economic development pathway,and establishing three change scenario models(sustainable development,intermediate route,and regional competition).The optimal allocation model of soil and water resources with coupled multidimensional objectives(resource,social,ecological,economic and environmental)is constructed,and agricultural food productivity,water footprint,ecological footprint,carbon footprint,surface source pollution,Gini coefficient and economic benefits are calculated,and the agricultural soil and water resource allocation plan is evaluated according to the comprehensiveness,balance and security of the allocation objectives,and a synergistic A comprehensive regulation scheme of water and soil resources that can cope with changing scenarios and have a synergistic resource-social-economic-ecological-environmental multidimensional development.The results show that the change of water allocation follows the rule of regional competition>intermediate route>sustainable development,and the total allocation of groundwater is 2.758 billion m~3,3.565 billion m~3 and 3.801 billion m~3 under the sustainable,intermediate and regional competition models,respectively.(2)Dynamic correlation analysis of sustainability of agricultural soil and water resource use under uncertainty.Based on hydrological parameter estimation,hydrological distribution line shape selection,stochastic simulation,and different dimensional regulation schemes,the response of agricultural sustainability and agricultural soil and water resources use to changing environments can be obtained.The dynamic correlation probability distribution of agricultural soil and water resources dynamics on regional"five dimensions"and sustainability and the reference interval of soil and water resources management that can cope with the changing environment can be obtained.Sustainability correlation analysis using fuzzy C-mean clustering was used to obtain a two-layer dynamic response function of agricultural soil and water resource use-dimensional objectives-whole sustainability.The results show that the initial surface and subsurface irrigation water intervals should be regulated in the ranges of 600-800(10~7m~3)and 400-600(10~7m~3),respectively,and the total amount should not be greater than1150(10~7m~3),and the corresponding planting area should be controlled in the range of 566-612(10~4hm~2).The Heilongjiang area of the Songhua River Basin in China should be appropriately reduced in the present irrigation water volume and increase the planting area.When the irrigation water volume is reduced by 5%and the planted area is increased by 5%,the sustainability of the area can be improved by 5.04%.(3)Virtual water flow analysis of food crops.Based on the social equity approach and input-output analysis,the virtual water flow momentum generated by food trade was measured.And the effects of various factors on virtual water flow of food crops(meteorological factors,agricultural production factors,and socio-economic factors)were analyzed qualitatively and quantitatively through mathematical and statistical methods and improved Douglas function.Pearson correlation coefficient analysis was used to evaluate the sustainability of the resource-environmental impact and water utilization impact generated by the virtual water flow.The results showed that the virtual water flow generated by rice and maize export is the main part of the crop virtual water flow momentum,agricultural production and socio-economic factors are the main factors affecting the crop virtual water flow,and the virtual water flow can bring a certain degree of water stress and environmental burden to the region.