Climate Changes Impact On The Snow Covered And Runoff In Kelan River

The respondence of snow cover to climate warming is one of the hottest topics incurrent scientific research. The acknowledge of process change and characteristics ofsnow cover and runoff provide an important basis for comprehensive developmentand utilization of water resources, scientific management and optimized dispatching.It also plays a decisive role in the lives of local people and social and economicdevelopment, meanwhile, ensures the sustainable development of agriculture andanimal husbandry and economy. In recent decades, with climate warming, thehydrologic process of Crane River Basin has changed a lot with advanced runoffmonths, obvious rising temperature and increased snow cover in winter and spring.All the changes will lead to increasing snowmelt flood and destruction. Changes inthe hydrological processes caused by climate change have a huge impact on the citywater supply and agricultural production along the Crane River Basin. Therefore,study on the impact relationship between the snow and runoff has a very importantsignificance.The thesis chooses data of monthly temperature, monthly precipitation, monthlyrunoff and the annual maximum snow depth of the Altai southern slope of the CraneRiver Basin from1957to2010and applies multiple statistical analysis methods inelaborating the interannual changes in temperature, precipitation, runoff and snowdepth, the era of change, seasonal variation, mutation and correlation analysis alongthe Crane River Basin. First, anomaly method and Mann-Kendall trend analysis areused to analyze temperature, precipitation, maximum snow depth and runoff trends.Second, Mann-Kendall mutation test is applied in testing mutation of temperature,precipitation, maximum snow depth and runoff. Last, correlation analysis andmultiple regression method are used to obtain the detailed relationship of runoffchanges with temperature, precipitation and maximum snow depth changes. Thefeedback and the effect of the snow depth, river runoff change and climate arediscussed to reveal the impact of the snow cover change on runoff.The studies have shown that, with climate warming, temperature, precipitation,maximum snow depth and runoff have a trend of increasing. Among the three factors,the response of volume of runoff to the amount of precipitation is the best, then comesthe maximum snow depth and the temperature. As for the temperature, it rises mainlyin winter.1987is the mutational site of temperature and passed the a=0.01significance test. The increase of temperature after1987was a catastrophe with theobvious increase trend of precipitation along the Crane River Basin. As for the snowdepth, it increases with the climate warming. Seasonal snow cover has littleinterannual fluctuation which means it is relatively stable. Seasonal snow cover variesfrom winter temperature and precipitation. As a result, the analysis of the three factorsshows that the interannual variability of seasonal snow is weakly negativelycorrelated to average winter temperature fluctuations and positively correlated withthe fluctuations of the winter precipitation. As for runoff, the annual runoff showedan increasing trend. The maximum monthly runoff moved up from July to May with a decrease in summer and an increase in spring. The regression equation of runoff andsnow depth, precipitation and temperature,Y=-0.7394xt+0.0595xp-0.1126xd+16.2082, is established to show that precipitationcontributes more to runoff than temperature and maximum snow depth. The tendencyof temperature and snow depth is negative, which shows that runoff is negativelycorrelated to them and negatively consistent with their correlation coefficient. Thesignificance test to the partial regression coefficients shows they have passed thea=0.05reliability significance test.