Study On The Resilience And Spatio-temporal Evolution Of "Water Resources,Society-Ecology" In Tarim River Basin

In recent years,with the rapid development of social economy and the change of external conditions such as climate conditions,the relationship between water resources,social economy and ecological subsystems has become closer and more complex.The high-intensity social economic activities not only cause the waste of water resources,but also lead to a series of ecological problems.At the same time,poor natural conditions and ecological environment also reduce the potential of social and economic development.Tarim River Basin is rich in culture,oil,gas and salt resources,which has important cultural and strategic value.However,the social and economic level of the basin is relatively backward and the natural resources are relatively scarce,which not only leads to more complex response relationship among subsystems,but also seriously restricts its sustainable development.System resilience mainly refers to the restoration of the system to the original state or equilibrium under the influence of external pressure such as natural disaster and its own stress,which is a further interpretation of sustainable development.Therefore,identifying system resilience is key to ensuring sustainable development of watersheds.At present,studies on the resilience of the "water-society-ecological" system and its subsystems focus on the theoretical framework,while quantitative studies are relatively few.Meanwhile,relevant studies at the catchment scale are still to be carried out.Taking the Tarim River Basin as the research object,based on the resilience of each subsystem,social hydrology and other related concepts,this thesis constructs the resilience evaluation index system of water resources system and socio-economic system respectively.Based on the meteorological precipitation and socio-economic data of the Tarim River Basin from 2000 to 2020,The entropy weighting method and TOPSIS algorithm were used to determine the resilience development level of water resources and socioeconomic system.An ecosystem resilience assessment model was built based on "landscape background-exposure degree".Based on the remote sensing data of the study area in 2000,2010 and 2020,the ecological resilience of the basin was quantitatively described.Finally,based on the calculation results of water resources,social economy and ecosystem resilience,entropy weight method and TOPSIS algorithm were used to determine the resilience of the basin complex giant system.Based on the quantitative evaluation of the toughness of each subsystem,the main factors of the toughness development of the composite giant system and each subsystem at different scales are explored by using the obstacle degree model.The main conclusions are as follows:(1)During the study period,there are differences in the spatial and temporal variations of the resilience of the complex system and its subsystems in the Tarim River Basin.The toughness index of complex giant system shows a slow rising trend and changes gently.The resilience index of water resources system in the basin showed a slow decline.The overall resilience of the social and economic system increased significantly;The horizontal evolution characteristics of ecosystem resilience in the basin showed an inverted "U" shape,increasing first and then decreasing.The toughness level is mainly in the medium level.The spatial distribution pattern was "high in the west and low in the east",but the spatial distribution was not obvious before 2010.The spatial distribution of ecosystem resilience in the basin showed obvious spatial distribution characteristics: low in the center and high in the periphery and had a high correlation with geographical conditions.The resilience of water resources and socio-economic system showed a distribution pattern of "high at both ends and low in the middle",that is,upstream > Downstream > Middle of the stream.(2)From 2000 to 2020,the spatio-temporal variation trend of each criterion layer index of each subsystem in the basin was significantly different.The index of water resources pressure and state showed a decreasing trend,while the index of response capacity showed an increasing trend.However,the water resource pressure and response capacity are upstream > Downstream,The spatial distribution pattern of the middle reaches,and the state index showed a gradually decreasing trend with the flow direction.In recent years,due to the good economic development and the support of economic policies in the basin,except the social management level has a slow decline trend,the corresponding indicators of the other criteria level of the social economic system have a rising trend.The habitat quality and species diversity of the basin fluctuated and decreased during the study years,while the ecological risk index increased first and then decreased,indicating that the ecological fragility of the basin increased.(3)The development of the water resources,social economy and ecology system in Tarim River Basin is mainly influenced by the development of the social economy subsystem,but the development of the water resources subsystem is also the key slow variable affecting its development.The development of resilience of water resources subsystem in the basin is mainly affected by the index of surface water/groundwater exchange capacity and the rate of evaporation change and vegetation area change in the response system.The resilience of the socio-economic subsystem of the basin is mainly affected by the index reflecting the industrial water security ability and the social insurance coverage.The resilience of watershed ecological subsystem is mainly affected by species diversity and habitat quality.