Impacts Of Climate Change In Jing River Basin On The Runoff

In this paper, the character of climate change in Jing River basin is based on the observed data of monthly air temperature, monthly precipitation, monthly evaporation over the period from 1960 to 1999. We analyzed the trend, periodic, abrupt point of climate change of Jing River basin. We also analysed the relation between temperature.precipitation, and evaporation. The result show that the temperature has significantly increased and the long-term warming rate of mean temperature change 0.10℃per ten years in Jing river area. The precipitation shows decreasing but not so significant. Air temperature was increasing in autumn and winter, the warming rate of mean temperature change are 0.30℃per ten years and 0.25℃per ten years. Precipitation was decreasing in spring and autumn and the evaporation have decreased significantly, especially in summer and spring, the trend factors are -0.699 and -0.301, through the confidence test of 95 percent confidence level. In order to check the abrupt point of temperature, precipitation and evaporation,we use Mann-Kendall Method and Cumulative departure method. The conclusion as follow: The temperature and the precipitation have no abrupt point, and evaporation abrupt point analysis finds 1963 is the abrupt point. Power Spectrum Analysis of annual average temperature discover 26 years significant period. Spectrum Analysis of precipitation show 8.7 and 4.3 years period, but not significant. And the evaporation has 26 years significant period.Moreover,we analysed the correlation coefficient between temperature,precipitation, and evaporation. The result show that temperature and evaporation have positive correlation significantly, precipation and evaporation have significantly negative correlation.In order to analyze the trend of runoff change of Jing River,We collect the runoff data from 1954 to 2006 of Zhang Jia shan by using some mathematical statistical methods. The result shows that: Nearly 53 years the runoff of Jing River, has a few changes in the occasion of abundant and dry periods, 1954 to 1963 is even water period, 1964 to 1970 is abundant water period, 1971 to 1996 is even water period, 1997 to 2006 is dry period. The yearly distribution of the runoff is uneven, it has a high degree of concentration (that is: the lowest of the flow is in January, February to May rise slowly, from the dramatic increase in June, to achieve maximum value in August, September significantly reduced, and in December achieve minimum). The unevenly coefficient of yearly runoff distribution C vy is 0.598, reflects the runoff of Jing River distribute unevenly of the year. The runoff coefficient of variation CV is 0.4, reflecting the Jing River runoff annual changes instability. Carrying out the regression analysis between the runoff volume and climatic factors (temperature, precipitation, evaporation) establish the regression equation, further explore the runoff responses of Jing River to climate change, conclusions are as follows: the precipitation and the stream discharge have a good positive correlation in common on situation except in special years, and the response feature of hydrological year is more or less 10%(or 20%, or 30%)than normal, the flow of runoff is more or less 9.8%(or 19.6%, or 29.3%).This article makes use of the grey related analysis method mainly to study the interreaction between the surface runoff change of Jing River and climate factors. The result indicates the related degree between the runoff of Jing River and the climate factors: r precipitation> r temperature> r evaporation, this indicates the precipitation is very important in maintaining the change of the runoff in Jing River basin.