Socio-Hydrologic Analysis Of Runoff And Sediment Changes In The Kuye River Basin Based On System Dynamics

With the development of economy and society and the growth of population,human intervention in the natural ecological environment has gradually become larger,the ecological environment has been destroyed to a certain extent,and the contradiction between people and water has become increasingly prominent.Especially in the Loess Plateau,soil erosion is relatively serious,and in recent years runoff and sediment have shown a sharp decrease trend.There are both natural and economic and social reasons for the sharp reduction in runoff and sediment.Therefore,it is of great significance to study the causes of runoff and sediment changes in Kuye River Basin based on the theory of socio-hydrology.According to the theory of socio-hydrology,this study based on the hydrological data of Kuye River Basin,as well as economic,social,and population data,the system dynamics(SD)method was used to construct a socio-hydrologic coupling model of Kuye River Basin using Vensim software.Using the dynamic system analysis of the model,combining the qualitative and quantitative methods to analyze the impact of economic and social factors on the changes of runoff and sediment in Kuye River,and simulating and predicting the future change trends,the research conclusions are as follows:1.Analyze the changes of socio-hydrologic factors in the basin over the past 40 years.The construction of silt dams in the watershed has shown a declining trend in recent years;Coal mining volume and the GDP of the basin have also increased rapidly;The rural population has declined sharply;At the same time,the economic investment for water and sand control has shown an increasing trend;The area of forest and grassland in the watershed gradually increased,and the area of cultivated land gradually decreased.2.Based on the theory of socio-hydrology and the systematic analysis of the internal subsystems of the economic,social,land use,ecological and hydrological subsystems of the Kuye River Basin,the system dynamics is established with the change of runoff and sediment as the core of research.After verification and analysis,the model is suitable for the study of the socio-hydrologic coupling model.3.Through the analysis model,the changes of runoff and sediment in Kuye River can be divided into two stages: 1980-1998 and 1999-2017.Quantitative research on social impact factors shows that the largest impact on runoff during the 1980-1998 period is the rural population,and the greatest impact on sediment is the construction of silt dams.The greatest impact on runoff and sediment during the period 1999-2017 was vegetation cover.4.By using the established system dynamics model and selecting the control variables,the future changes of runoff and sediment under the two different schemes of current situation continuation type and sustainable development type are predicted respectively.The results show that the runoff will continue to increase in the future under the sustainable development plan.5.According to the reason of the change of runoff and sediment in the river and the change of runoff and sediment in the future,combined with the actual situation of the basin,the corresponding policies and suggestions are put forward for the sustainable development of the basin in the future.