Simulation Of Water Cycle In The Catchment Area Of Nanpeng Reservoir

Due to the needs of benefit promotion and flood control,a large number of scholars have carried out relevant research on large basins in China,such as the Pearl River,the Yangtze River,the Yelow River and other basins.However,for the widely distributed mountainous small watersheds,research on their hydrological processes is relatively scarce and needs to be strengthened.This study takes the upstream area of Nanpeng Reservoir as the research area,establishes a WEP-L distributed watershed hydrological model,and conducts hydrological numerical simulation work.Complete parameter calibration and validation of the constructed distributed model,and explore the applicability of the WEP-L model in this area.Simulated the runoff characteristics under different land use types,analyzed the runoff situation in sub watersheds based on different land use types,discussed the factors that may affect the simulation of the WEP-L model in the region,and conducted reasonable analysis and summary of the research.This can provide theoretical reference for hydrological simulation with small watersheds as research units.The main conclusions are as follows:(1)The study selected the WEP-L model for runoff simulation in the study area,and divided the upstream of Nanpeng Reservoir into 34 sub watersheds.Hydrological simulations were conducted on the runoff process in the study area using collected temperature,sunshine,temperature,humidity,precipitation data from nearby meteorological stations,as well as soil properties and land use types.At the rate interval of the model,the Nash efficiency coefficient for runoff simulation is 0.74,with a relative error of 4.7%;During the validation period of the model,the Nash efficiency coefficient for runoff simulation was 0.7,with a relative error of 7.5%.The simulation results were relatively reasonable.(2)Based on the hydrological simulation results of the Nanpeng Reservoir catchment area,three sub watersheds with different land properties were selected in the area,namely forest land,paddy field,and residential land.Based on this,runoff simulation was conducted for the sub watersheds.The corresponding runoff coefficients of the three sub watersheds with different underlying surface types were analyzed during the rainy season from April to August 2019.Among them,the runoff coefficient of the paddy sub basin is 0.07;The runoff coefficient of the forest sub watershed is 0.26;The runoff coefficient of the residential land sub basin is 0.67.Based on the simulation results of runoff generation on different underlying surfaces,the water circulation situation in each region was discussed,and the selected scenario for runoff generation and concentration simulation on the underlying surface was more reasonable.(3)Based on the simulation of the runoff process in the study area,the overall runoff generation process in the catchment area of Nanpeng Reservoir is analyzed.During the selected rainy season from April to August 2019,the average runoff depth in the study area is 187.95 mm,the runoff coefficient is 0.28,the evaporation is 301.30 mm,and the infiltration is 208.71 mm.