| In the background pf water pollution prevention and control in all parts of the country,the landscape planning for the purpose of watershed ecological restoration should take into account the difference between water quality and hydrology benefit of different vegetation planning schemes.If the water quality and hydrological benefits of the plan can be compared by calculating the water cycle process,the landscape garden can be chosen for the landscape garden.The plan provides a scientific and reasonable reference.This paper,taking the Hu Jia Qiao River Basin of Mao Li Hu in Hunan Province as the research object,collected the data of the basin through field investigation and literature search,and constructed the SWAT distributed hydrological model of the current situation of the Hu Jia Qiao River Basin in Mao Li Hu.In this paper,I set up five different vegetation cover types,and compared the difference between the total nitrogen load,total phosphorus load,sediment yield,surface runoff depth,evaporation and surface water infiltration of six water quality and hydrological indexes of the five covered types.The results show that the water quality and hydrology benefit of different vegetation types are different,and that the plant and shrubs suitable for local growth have the strongest control benefits for the total nitrogen pollution,and the surface water infiltration and the water conservation ability can be enhanced.The simulation results show that compared with other vegetation types,The study of evergreen and mixed forests in the basin is not only conducive to reducing the total phosphorus pollution load,but also better in reducing the sediment and reducing the surface runoff in the basin.A plan is designed for the ecological restoration of Hu Jia Qiao.On the basis of the plan,two adjustment schemes are adjusted,and the SWAT simulation is carried out respectively.The simulation results showed that there were significant differences in the nitrogen and phosphorus load of each scheme.The vegetation cover area was significantly correlated with the total nitrogen load,total phosphorus load,sediment yield,runoff depth,evaporation and infiltration.The simulation results showed that the greater the vegetation cover area,the better the water quality and hydrology benefit of the basin.It is found that the water quality and hydrology benefit of each scheme are better than the situation.Themaximum total nitrogen load of the vegetation cover area of the plan is reduced by 14.3%,the total phosphorus load is 20.1%,the sediment yield is 20.1%,the sediment yield is 51.1%,the surface diameter is 51.1%,and the surface diameter is 51.1%.The flow depth is 20.03mm,which is 23.5%lower than the present situation and the maximum infiltration rate is 271.01mm.The adjusted scheme is the best scheme for water quality and hydrological benefit.However,due to the different areas between the schemes,the ’water quality and hydrology benefit of the area of the unit for returning farmland to the river basin are adjusted scheme 2>plan scheme>adjusted schemel.The total nitrogen load of the adjusted scheme 2 is reduced by 13.8%,the total phosphorus load is 0.180kg/hm2 ratio 19.6%,the sediment yield is 0.91t/hm2 ratio 51.1%,the surface runoff depth is 20.12mm ratio 22.3%,and the infiltration amount is 269.44mm.In theory,the plan is an ideal scheme.If the actual construction cost and the workload of land acquisition need to be considered,a more feasible adjusted plan 2 is recommended. |
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