The Impact Of Climate Change And Human Activities On The Hotan River Runoff

The Yutian River,one of the three major sources of the Tarim River,is located in the oasis of the desert,and its runoff changes have a direct impact on the local natural environment,irrigation and water and animal husbandry.In recent decades,the basin has undergone a series of changes in runoff under the combined influence of climate change and human activities.In this paper,the meteorology,man-made data and runoff data of the two tributaries of the Hetian River(Karakha River and Yulong Kashi River)were collated and analyzed to understand the interannual variability of runoff,temperature and precipitation in the two rivers And further analyzes the influence of climate and man-made factors on the basin,and the factors that have the greatest influence on the runoff of Hetian River are obtained,and the influence degree of the factor on runoff is analyzed.The results are as follows:(1)The fluctuation rate of the annual runoff of Uluwati station is generally fluctuating,the change is not significant,the fluctuation rate is only 0.0719(108m3)/10 a.According to the variation characteristics of runoff,it is divided into three stages:1957-1980,1981-1988 and 1999-14.The predicted value and the actual value of the Ukrainian station are in good agreement with each other,and the predicted value is consistent with the trend.The runoff ratio of the Ukrainian station is not significant,and the Cv value is 0.19.(2)The trend of annual runoff variation with Guzilok station is generally slow,fluctuating and increasing,and the fluctuation rate is only 0.0274(108m3)/ 10 a.According to the characteristics of runoff variation is divided into three stages: 1957-1979,1980-1999 and 2000-2014.The predicted value and the actual value of the same station are basically consistent,the curve fitting is better,and the forecast value is also the trend of increasing volatility in the future.The runoff ratio of the runoff is not significant,and the Cv value is 0.18.(3)Hetian River is generally very uneven in the distribution of runoff throughout the year.For the Krakawashi River and the Yulong Kashi River,the latter is more evenly distributed than the former.The two rivers accounted for 72.9% and 80.7% ofthe total annual runoff respectively,while the other three-season runoff accounted for only 27.1% and 19.3% respectively.(4)The overall temperature is slowly increasing trend,but the change is small.The trend of temperature anomalies in the watershed is more significant;the MK test mutation year is in 1996;the temperature of the river basin Sequence 28 a scale oscillation period is the strongest,interval study of the change period is about 18 a.(5)The overall characteristics of precipitation are combined with anomalies and differential product curves.The difference curves are parallel and almost no fluctuating,and the change is not significant.During the year,the variation of MK is in 2001;the trend analysis shows that the significance is not high;The sequence of precipitation is consistent with the temperature.(6)In the correlation analysis between the climatic factors and the annual runoff of the Uluwati station,the correlation coefficient between the Ukrainian station and the temperature is the best,reaching 0.52.The correlation coefficient between the station and the temperature is the best 0.47.In the correlation analysis between the human factors and the annual runoff of the Hetian River,the correlation coefficient between the irrigated area and the Wuzhang was the largest,reaching 0.43.In the correlation analysis with the Guziluo Ke station and each influencing factor,the irrigated area The correlation coefficient with the same station is the largest,reaching0.42.(7)Respectively,the establishment of natural and human factors on the two hydrological stations runoff regression analysis:(1)When the temperature of the Hetian River Basin is 3% higher,the annual runoff of the Krakaw River is 3.6%,and the Yulong Kashi River is 9.5% more.When the temperature is reduced by 3%,the runoff will decrease by 2.6% and 3% When the distance is 5%,the runoff is 6% and 12%,and the runoff is reduced by 4.8% and 0%when the decrease is less than 5%.When the distance is 10%,the runoff is 12%,18%10%,runoff decreased by-8.9%,4%.Indicating that the temperature in the Hetian River Basin is the most prominent factor in the change of runoff.(2)When the irrigation area is 5% more,the annual runoff of the Krakaw River will be 6% and the Yulong Kashi River will be 5% higher.When the area is reduced by 5%,the runoff will decrease by 6% and-0.3% The runoff will be reduced by-10%,3.5%;when more than 15%,the annual runoff will be more than 11%,12%;When15% reduction,runoff will be reduced by 15%,6.7%.Indicating that the irrigation area in the Hetian River Basin has the most prominent effect on the runoff change.