Quantitative Effect Of Precipitation Spatial And Temporal Changes On Water Cycle In Gulang River Basin

The Shiyang River Basin is the third largest inland river in Northwest China,but the river water resources are very scarce.As an oasis in the desert,the Minqin Basin is facing the danger of dryness.With the maturity of artificial rainfall and artificial snowfall,artificial precipitation in this area is feasible.In this studies,the Gulang River Basin in the upper reaches of the Shiyang River.Firstly,collecting the meteorological and hydrological data of the area,and selecting the hydrological model suitable for the Gulang River Basin.Then,the two stations of Wushaoling and Toudaogou were used as the research objects to increase the precipitation of 10%and 20%,and quantitatively study the changes of hydrological cycle in the Gulang River Basin under 44 scenarios,including average flow of the basin,average evapotranspiration,average soil water content changes in time and space.According to this study,the following conclusions can be drawn:?1?In the Gulang River Basin where data is scarce,the SWAT model has good applicability.Based on the meteorological data of Wushaoling and Gulang stations and the precipitation data of the Toudaogou station,estabilish the SWAT model and adjust the parameters.The final rate of the Nash efficiency coefficient E_ns and the determination coefficient R² for the regular 2015 to 2016 and the verification period 2017 are both greater than 0.6,indicating that the model is applicable in this region.?2?Under the scenario of the same precipitation increase,compared with the Toudaogou station,the increase of precipitation in Wushaoling station increased the watershed flow and soil water content,and the evapotranspiration increased less.For example,when the annual precipitation of Wushaoling increased by 10%and 20%,the export flow of the basin increased by 20.69%and 43.29%,which were greater than 17.98%and 41.07%of the Toudaogou.Therefore,the artificial precipitation effect at Wushaoling Station is better.?3?In terms of time,the impact of precipitation changes on hydrological factors has strong seasonal characteristics.If the annual precipitation in Wushaoling increased by 10%,the export flow in the basin increased by 21.2%in August,while in March it only increased by 2.68%.When summer precipitation increases by 10%,the average annual flow of watershed exports increases by 13.96%,while the annual average flow increases by 1.77%when spring precipitation increases by 10%.The increase of precipitation in the year,summer,July and August has the greatest impact on hydrological factors,and the increase in precipitation in the month not only affects the changes of hydrological factors in the current month,but also affects the hydrological elements in the next few months.The influence is weakened over time and eventually stabilizes.?4?In terms of space,precipitation changes have a large regional difference in the impact of hydrological factors.For example,when the annual increase of water in Wushaoling is 10%,the flow in the eastern part of the basin increases by 20%,while in the western mountainous area,it increases by more than 20%.Therefore,it is possible to select a scenario with a large impact on runoff in the eastern region as a reference for artificial precipitation.