Co-evolution And Driving Mechanism Of Coupled Socio-hydrological System In Arid Areas

In the age of Anthropocene,the human society and natural ecosystem has become a coupled socio-ecological system.As the core of ecosystem,water also closely interacts with human society.Humans and water also has become a socio-hydrological system.In arid areas,the internal coupled feedbacks,which functions as important mechanism for co-evolution of humans and water,are even more significant.The study about the co-evolution and forcing mechanism of the socio-hydrological system has academic significant and practical value for understanding the mechanism of coupled humans and water,developing socio-hydrology theories and methods,and guiding the policy in water resource management.In this thesis,a theoretical framework for analyzing the co-evolution of the socio-hydrological system based on nature-society forcing mechanism and a socio-hydrologic model framework based on coupled water balance,economic activity and societal decision-making,are constructed.The interacting social productive force and natural variability is proposed as the dynamic foundation of co-evolution of the socio-hydrologic system.A historical stage analysis about 2000 years of co-evolutionary trajectory of socio-hydrologic systems in Tarim River basin is conducted.It shows that the external technological and institutional factors have dominated the development of local social productive forces for a long time.A further historical analysis about the co-evolutionary trajectory of socio-hydrologic systems in Bayingolin during 1950 to 2010 indicates that when the social productive forces dominate the co-evolution,the natural conditions like water and land resources limitation has also plays key role that shapes the development of the social productive force.In order to improve the description of the social decision-making processes,a concept of policy makers' sensitivity is defined to represent the policy makers' willing on a policy mix consists of irrigation land control and water-saving promotion policies.According to this concept,the policy variables are able to be quantitatively defined and the evolution of the policies are able to be dynamically simulated.Based on the social decision-making model,coupled with the water balance and macroeconomic processes,a conceptual socio-hydrologic model is built to simulate the development of the water-saving agriculture development and the adaptive evolution of corresponding policy variables about irrigation land control and in Bayingolin during 1998 to 2010.The results capture the dynamic mechanism of coupled economic rebound effect due to technology improvements and social adaptation effect about policy adjustment upon the irrigation efficiency paradox.With multiple social investigation methods,the perception on water-saving measures of different groups are compared and analyzed.It shows that the deep social causes for applying improper loose irrigation land control policy in early stage of water-saving agriculture development,is that humans lack the cognition about the coordinating use of land and water resources.Based on the investigation study,with the socio-hydrologic model built for water-saving agriculture in Bayingolin,the impacts of different initial irrigation land control policies on irrigation efficiency paradox are simulated and compared.The results show that applying simulated proper irrigation land control policy beforehand,may lead to irrigation efficiency paradox even earlier and seriously harm the agricultural production due to low irrigation land growth rate.It is better to apply moderate irrigation land policy at the early stage of water-saving agriculture development in arid areas,with consideration of the coupled feedbacks of the socio-hydrological systems.This method and results provide reference for policy making about developing water-saving agriculture in arid areas.