The Simulation Study On Eco-hydrological Response Of Vegetation Restoration In Zhoujiagang Watershed,Maolihu Lake,Jinshi City,Changde

Ecological restoration is one of the projects that has actively responded to the construction of ecological civilization in China.In recent years,the impact of natural factors and many unreasonable human factors on the Maolihu lake has changed the characteristics of the underlying surface of the river basin,which in turn has led to land degradation,vegetation destruction,water and soil degradation.The worsening of the loss and the deteriorating condition of water resources have caused tremendous damage to the ecological environment in the region,and ecological restoration is imminent.Under the background of the construction of ecological civilization and the development of vegetation restoration projects,it is of great theoretical and practical significance to explore the impact of cover changes on the ecological and hydrological effects of the basin.This study takes the small watershed of Zhoujiagang in Maolihu Lake,Jinshi City,Hunan Province as the research object,and plans to establish different vegetation recovery scenarios in the small watershed based on the current vegetation of the watershed;SWAT eco-hydrological model is selected as the research tool and supported by the ArcGIS software platform.The model database of the Zhoujiagang small watershed was constructed;based on the daily average meteorological data of the river basin from 1980 to 2010,the SWAT model was used to simulate the current vegetation pattern in the small watershed of Zhoujiagang and the ecological hydrological process of the next year under different vegetation restoration scenarios;The hydrological factor effect under different vegetation scenarios was analyzed,and the impacts of landuse and vegetation pattern changes on the ecological hydrological process of the river basin and the regulatory mechanisms were analyzed from the perspective of ecological hydrology and vegetation restoration;and the ecological hydrology of each vegetation restoration scenario was analyzed.The significance test of the effect was designed to select a program with better ecological and hydrological effects for the ecological restoration of the Zhoujiagang watershed in Maolihu Lake.The main findings of this paper are as follows:The results from different scenarios project on the ecological hydrological process of the river basin show that the annual reduction in evapotranspiration,surface runoff,and sediment yield reduction are most significant with the Scenario Five,followed by the Scenario Two,the third is the Scenario Three,and finally is the Scenario Four.The annual evapotranspiration in the Scenario Two increased by 7.62mm,annual runoff decreased by 8.33mm,annual sediment production decreased by 0.63t/hm2,annual evapotranspiration by Scenario Three increased by 8.53mm,annual surface runoff decreased by 8.18mm,and annual production the amount of sand was reduced by 0.62 t/hm2;the annual evapotranspiration of the Scenario Four increased by 7.15 mm,the annual surface runoff decreased by 6.31 mm,the annual sediment production decreased by 0.53 t/hm2,and the annual evapotranspiration of the Scenario Five increased by 17.62 mm.The annual runoff decreased by 30.16mm,and the annual sediment production decreased by 2.27t/hm2.The results show that:From the overall ecological and hydrological effects of different scenarios project during the year,the ecological and hydrological effects of the vegetation pattern of the Scenario Two,the Scenario Three,the Scenario Four,and the Scenario Five are all stronger than the ecological hydrological effects of the Scenario One vegetation pattern,and the dewatering of the basin is taken.Reforestation and the establishment of forest wetlands and other vegetation restoration measures can increase the evapotranspiration in the river basin and have a positive effect on sediment reduction,and improve the ecological hydrological benefits.From the results of different scenarios project on the basin's ecological water quality process,the reduction effects of organic nitrogen and organic phosphorus load are all the most significant with the Scenario Five,followed by the Scenario Two,the third one is the Scenario Three,and the last is the Scenario Four.The organic nitrogen and organic phosphorus load of the Scenario Two was reduced by 0.70 Kg N/hm2 and 0.09 Kg P/hm2;the organic nitrogen and organic phosphorus load of the Scenario Three were reduced by 0.68 Kg N/hm2 and 0.08 Kg P/hm2;The organic nitrogen and organic nitrogen load of Scenario Four was reduced by 0.58 Kg N/hm2 and 0.07 Kg P/hm2;The Scenario Five of organic nitrogen and organic phosphorus load was reduced by 2.41Kg N/hm2 and 0.30 Kg P/hm2.In summary,from the comparative analysis of ecological hydrological processes and hydrological effects under different vegetation ecological restoration programs,we have reached the same conclusion in the end:In each vegetation restoration program,the recovery scheme with better ecological and hydrological effects is the Scenario Five,followed by the Scenario Two,the third one is the Scenario Three,and the last is the Scenario Four.