| In view of the Xinjiang away from the ocean,deep in the inland,strong features such as rainfall,evaporation,determines its was a frequent drought and drought area,but due to lack of basic data of the region,monitoring site exiguous sex,greatly restricted the right area of the damage caused by the drought and law,brought great pressure to disaster prevention and mitigation,urgent need to develop drought research to supplement and perfect the relevant aspects of the blank,better improve the guidance of theory and practice.In this paper,the Kashi River Basin in the western mountainous area of Tianshan Mountains was taken as the research area,with the help of measured meteorological and hydrological data,the applicability of regional hydrological drought index(SHI)was analyzed,and the response relationship between hydrological drought and meteorological drought was discussed combining with standardized precipitation index(SPI).Climate scenario data(NEX-GDDP)were used to build SWAT model,and the future was explored the spatial-temporal distribution characteristics of meteorological drought and hydrological drought under the same scenario and the relationship between them.The main achievements of this paper are as follows:(1)The measured meteorological and hydrological data were used to select the hydrological and drought indicators suitable for the study area.Combined with SPI,a hydrological meteorological nonlinear function model was constructed to explore the response relationship between hydrological and meteorological drought.The results showed that SHI was the most accurate drought monitoring index,which could comprehensively identify or reflect the drought characteristics of the study area.The logarithmic function model(Logarithm)with three parameters(log3P1)could be used to better characterize the response relationship between hydrological and meteorological droughts.At the 3-month scale,when the meteorological drought lasted at least 1.10 months and the drought magnitude was at least 0.83?the hydrological drought would be induced;at the 6-month scale,when the meteorological drought lastsed at least 1.60 months and the drought magnitude was at least 0.91,the hydrological drought would be induced.(2)In the NEX-GDDP downscaling data,the BCC-CSM1-1 model and the NorESM1-M models were respectively used as SWAT model driving data to simulate runoff.It could be seen that the trends of simulated runoff and measured runoff of the two models were basically the same.The efficiency coefficient,correlation coefficient and relative error of the BCC-CSM1-1 model were 0.80,0.82,15%and 0.81,0.82,3%respectively in the period of calibration and verification;the efficiency coefficient,correlation coefficient and relative error of the NorESM1-M model were 0.73,0.77,12%and 0.76,0.81,20%respectively in the period of calibration and verification.The BCC-CSM1-I model had a strong ability to simulate runoff in the study area and could be used as a climate model for future drought prediction.(3)The BCC-CSM1-1 model was used to predict future drought.It could be seen that in general,the frequency,intensity and range of drought of meteorological drought and hydrological drought would increase significantly in the future,and the areas with significant increase were mainly concentrated in the middle and lower reaches of the basin.In different seasons,meteorological drought was easy to occur in spring and summer festival,and hydrological drought was easy to occur in summer and autumn festival.In different levels,the frequency of light drought was higher in meteorological drought,and the frequency of severe drought was higher in hydrological drought.In different periods,the intensity of meteorological drought and hydrological drought in the middle of the 21st century(2040-2059)under the RCP4.5 scenario was the most significant;in the near future of the 21st century(2025-2039)under the RCP8.5 scenario,meteorological drought was prone to occur,and in the late 21st century(2060-2079)hydrological drought was prone to occur.In the response relationship between hydrological drought and meteorological drought,the change of future meteorological and hydrological elements increased the uncertainty of response model,which made the critical conditions and historical periods of hydrological meteorological drought in different time scales under different scenarios in the future different. |
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