Research On Socio-hydrological Modelling Of Transboundary River Cooperation Evolution

The transboundary river is an important and special socio-hydrological system,and cooperation and conflicts between upstream and downstream are critical phenomena in the system.The socio-hydrological modelling can help to analyze the co-evolution pattern and driving mechanism of tranboundary river cooperation under climate change and the impacts of water use behaviors of upstream and downstream countries,which is significant for the mid-to-long-term transboundary river water resources management.The thesis puts forward a framework of socio-hydrological research on transboundary river cooperation.Based on the two basic forms of transboundary river water resources cooperation,including cooperation on reservoir operation and cooperation on water withdrawal,the thesis builds socio-hydrological models in Lancang-Mekong River and rivers in arid areas respectively.In Lancang-Mekong River,the cooperation evolution is simulated,and the effects of climate change,reservoir and political weight change of upstream,and compensation mechanism on cooperation evolution are analyzed,which offers policy recommendations to mid-and long-term management of transbounary rivers.In rivers in arid areas,the asymmetric responses of human water consumption during wet and dry periods are modelled,and the importance of institutional factors in transboundary river management is revealed.The main findings are listed as follow.A socio-hydrological theoretical framework of tranboundary river cooperation is raised,including characteristic variable,element structure and driving mechanism.Taking the two-agent transboundary river system as example,a model framework is raised,and critical variables,equations and scope of application are defined.Based on the frameworks,case analyses are conducted on the interactions between upstream and downstream in Columbia River Basin and Nile River Basin.A socio-hydrological model including hydrological simulation,reservoir operation,benefit calculation and policy feedback modules is built to simulate and analyze the evolution pattern and driving mechanism of benefits and cooperation in Lancang-Mekong River.The cooperation evolution process includes that the reservoir construction and operation in upper Lancang-Mekong River change the seasonality of downstream runoff,cooperation demands of downstream rise up because of the change of direct benefits,and the upstream countries change their cooperation actions to gain indirect political and diplomatic benefits.Based on the Lancang-Mekong socio-hydrological model,scenarios under runoff change,irrigation expansion,reservoir construction and change of political weights are simulated to analyze their effects on tranboundary river cooperation.The results show that there is low possibility of significant increase of conflicts in Lancang-Mekong Basin under the basic scenario.The upstream reservoirs will play a more important role in reducing risk of conflicts when the relation between water supply and demand is more strained.When compensation from downstream could bring more benefits beyond the river to upstream countries,the compensation mechanism could be sustainable.It offers important theoretical basis and policy recommendations to the mid-to-long-term transboundary river water resources management.Based on the data of transboundary rivers including Syr Darya River and Amu Darya River,and domestic rivers in arid Northwestern China,a socio-hydrological model of cooperation on water withdrawal is built,and the asymmetric responses of human water comsuption in wet and dry periods are revealed and simulated.The differences of the evolution of human water consumption between transboundary and domestic rivers are analyzed,and the significance of institutional factors in transboundary river management is underlined.