Analysis Of Predicting And Evoluting For Future Hydrologic Drought In The Illinois River Basin

Under the influence of climate change and human activities,the external conditions and internal relations of the hydrological process in the basin have changed significantly,making the shortage of water resources,water ecological degradation and other issues prominent increasingly,and becoming an important factor restricting for economic development gradually.Drought plays an important role in water circulation,rational allocation of water resources,drought prevention and drought resistance.The study of hydrologic drought plays an important role in water circulation,rational allocation of water resources,drought prevention and drought resistance.In this paper,the study area of the Illinois river basin was selected under the condition of land type constant for many years,and 9 kinds of meteorological data under 8 kinds of climate change modes were used as the basic data.First,the hydrological model used to simulate the future runoff data and MK(Mann-Kendall)trend analysis method was taken to analyze the result of the runoff trend,then,according to the simulated data to construct the hydrologic drought index to analyze the future hydrological drought prediction and evolution.Considering the gradient change and the number of sub-basins controlled by the site,the five sites for IL111420,IL115712,IL118860,IL119241 and IL126989 were mainly selected as the research objects.The main research and achievements as follows:(1)hydrological drought characteristicsIn a short time scale,the phenomenon of the drought is more likely,drought is less likely on a long time scale.With the increase of RCP concentration,the degree of drought is gradually intensified.(2)The impact of climate change on droughtWhen analyzing the effects of climate change on hydrology and drought.Precipitation is positively correlated with hydrologic drought index,while temperature,solar radiation and potential evaporation are negatively correlated with hydrologic drought index.Precipitation and solar radiation are the two meteorological factors contributing the most to hydrological drought.(3)Drought risk estimationWhen the drought risk was estimated,the results showed that on the time scale,the probability of drought was the highest under the climate change mode of MRI-rcp85,and the drought coverage area was the largest under the climate conditions of GFDL-rcp45 and MIROC-rcp45 on the spatial scale.At last,according to the risk situation of the region,the corresponding measures of disaster prevention and mitigation are taken,such as raising the reservoir capacity,improving the utilization rate of water resources,developing water resources and improving the ability of drought early warning and prediction.