Simulation Of Hydrological Effects On Vegatation Restoration Of Small Watershed In Songjiaping Creek,Maoli Lake With SWAT Model

As people pay more and more attention to the water resources and water environment,the impact of vegetation restoration on the ecological hydrological process is becoming more and more concerned.It is of great theoretical and practical significance to study the protection and ecological planning of water resources under different cover conditions.Distributed watershed hydrological model is currently the most commonly used tool for hydrological cycle research,and has been studied at home and abroad.The SWAT model,developed by the agricultural research center of the United States Department of agriculture,has a strong physical basis.It can predict the effects of human management measures and climate change on water supply through a continuous simulation of the changes in the runoff in the true environment for a long period of time,which plays an important role in the study of hydrological problems.This paper studies the eco hydrological process of vegetation restoration in the Song Jia Ping River Basin,and establishes the SWAT model to simulate its eco hydrological process.In a variety of scenarios,the ecological and hydrological effects of different vegetation cover conditions are simulated and calculated,and the response degree and change law of hydrological factors to vegetation change are studied,which provide scientific basis for vegetation restoration in the small watershed of Song Jia Ping River in Mao Li Lake,and the main research results are as follows:The hydrological effects of different vegetation patterns were mainly influenced by the change of rainfall.The variation of surface runoff,evapotranspiration and water yield were all consistent with the rainfall,and the maximum value appeared in the June-8 months of heavy rainfall.The surface runoff,evapotranspiration and water yield of the planning scheme and its adjustment scheme are less than those of the original land use,indicating that the ecological hydrological effect of the vegetation pattern after the planning is better than the ecological hydrological effect produced by the present vegetation pattern.The surface runoff,evapotranspiration and water production are all S5>S3>S4>S2,indicating that the hydrological effect of the plan is better than that of the adjustment scheme.The influence of different vegetation coverage on eco hydrological effect is wetland>deciduous forest>mixed forest.Compared with the original land use,the extreme plan has greater impact on the hydrological area than the increase of the arable land area.The effects of different vegetation patterns on water quality were not affected by rainfall,and organic nitrogen,organophosphorus and sediment yield were highest in April.Among them,the organic phosphorus load,organic nitrogen load and sediment yield of the planning scheme and its adjustment scheme were less than those of the original land use,indicating the ecological water produced by the planned vegetation pattern.The cultural effect is better than the present eco hydrological effect of vegetation pattern.The organic phosphorus load,organic nitrogen load and sediment yield were all S5>S3>S4>S2,which showed that the hydrological effect of the planning scheme was better than that of the adjustment scheme.The effect of different vegetation coverage on water quality is wetland>deciduous forest>mixed forest.Compared with the original land use,the extreme plan has greater impact on the water quality than the increase of the arable land area.To sum up,the influence of different vegetation patterns on hydrology and water quality has reached a consistent conclusion.The planning scheme is superior to the present vegetation pattern,and the planning scheme and its adjustment scheme have some effect on the hydrology and water quality of the small watershed of the Song Jia Ping Creek,especially in reducing the load of organic phosphorus and organic nitrogen in the river.In Scenario Planning and adjustment,scenario S4 has the best eco hydrological effect,while scenario S5 has the lowest eco hydrological effect.The change of forest land has the greatest impact on the eco hydrological effect of the study area,mainly in the increase of the area of woodland,which can reduce the surface runoff,evapotranspiration,water production and reduce the load of organic phosphorus and organic nitrogen in the basin and reduce the sediment yield.It is necessary to carry out proper cropland to forest.