| The hydrological cycle is an important part of the climate system.Climate change will certainly cause the change of hydrological information in time and space.At the same time,the hydrological system can produce important feedback on weather and climate by regulating the energy and water cycle between land and air.Arid area is very sensitive to global warming and its water resources system is fragile.Therefore,the interaction of climate and hydrology in arid area has a significant influence on the formation of regional microclimate and the hydrological change of basin.In this study,WRF-HYDRO model was used to simulate the climate and hydrological coupling situation in Daihai Basin,and meteorological statistics,runoff generation calculation and remote sensing analysis method were used to verify and calibrate the coupling results.At the same time,regional optimization of WRF-HYDRO model was carried out to determine the optimal parameters.The optimal WRF-HYDRO model was used to carry out short-term weather runoff coupling and long-term climate hydrological coupling in the Daihai Basin,and to reappear several rainstorm and flood events,as well as the climate change process and the temporal and spatial variation law of runoff during 1980-2020,and to analyze the reasons and future trends of hydrological factors change in the Daihai Basin.The main research results are as follows:(1)The interannual variation of precipitation in Daihai Basin was dramatic,with a mean of401.75mm fluctuating slightly from 1980 to 1994.From 1995 to 2011,except for the precipitation surge in a few years(1995,2003),the precipitation decreased to 371.39mm,and there were many dry years and wet years,with a sharp fluctuation.From 2012 to 2020,the fluctuation is small,and the EMA rises to 451.75mm.Although the interannual variation of evaporation fluctuated,it showed an upward trend,with an upward slope of 10.26.It showed an obvious fluctuating upward trend on the annual mean temperature,with an upward slope of 0.0402.In addition,the annual average temperature takes a period of 10 years,during which there will be two small fluctuations and one large fluctuation,and the fluctuations will increase.(2)Short-term weather runoff events in Daihai Basin mainly occurred from June to September.Short-term weather runoff events are seriously affected by natural precipitation,and the variation rule is basically the same as precipitation.Surface runoff is easy to break in the dry season.The discharge into the Daihai Lake showed a decreasing trend from 1980 to 2020.Although it picked up in 1996-1999 and 2005-2007,the rate of decline was sharp from 2008 to 2012.In 2012,the runoff into the lake had been reduced to 3.95×10~6m~3.Since 2013,the runoff into the lake has been flat.(5)Climate change and human activities are the decisive factors leading to the change of sea water volume in DAI,and human activities play a more important role.Irrigation and industrial water use are highly correlated with lake inflow and have a great influence on it.The main reason is that the global warming trend is obvious,the temperature rises,the evaporation increases,and the runoff generated by rainfall is evaporated into the air before it enters the Daihai Lake.(6)According to the prediction model,if human activities do not change,under the background of global climate change,the flow into the lake of Daihai will be reduced to zero in 2025.Now the protection of the Daihai basin is very necessary.Measures such as returning farmland to forests and grasslands and the spread of water-saving irrigation techniques are also very important.Climate-hydrological coupling in Daihai Basin not only makes up for the deficiency of observation data,but also accurately obtains the time and range of short-term weather events and long-term climate and hydrological change information in the basin,which provides the basis for water resources management,disaster prevention and mitigation in the basin. |
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