锡林河流域降雪识别及演变趋势研究

Snowfall Identification and Evolution Trend in Xilin River Basin

基于双温度阈值法利用锡林河流域4个国家气象站点1969-1979年10年的降水与气温资料,统计其降雪比例与日平均气温的关系,确定锡林河流域降雪判别的临界温度,拟合降雪识别指数方程。根据临界温度与识别方程估计流域内各站点1980-2016年的降雪量,并采用Mann-Kendall检验法对1969-2016年的降雪量进行突变检验,找出流域降雪的典型突变点,以突变点为界设立温度与降水变化模拟方案,量化反映其变化对降雪量变化的贡献。结果表明:临界温度与降雪识别方程组合的降雪识别方法,可较好的估计锡林河流域各站点的降雪量,相关系数均在0.89以上,误差在4%以内;1980-2016年锡林河流域各站点之间的估计降雪量变化趋势不一致,整个流域降雪量呈现出东增西减的趋势;根据Mann-Kendall突变检验结果取1980年为流域的典型突变点,设立温度与降水变化模拟方案,得出气温升高对降雪期各月的降雪量变化呈负贡献,降水量的增加则对降雪呈正贡献,气温与降水共同作用会促进降雪量的增加。

Based on the dual temperature threshold method,the precipitation and temperature data of four national meteorological stations in Xilin River Basin from 1969 to 1979 were used to calculate the relationship between the snowfall ratio and the daily average temperature,and the critical temperature of snowfall discrimination in the Xilin River Basin was determined,and the snowfall identification index equation was fitted..According to the critical temperature and identification equation,the snowfall of each station in the basin was estimated from 1980 to 2016,and the Mann-Kendall test was used to test the snowfall of 1969-2016 to find the typical mutation point of snowfall in the basin.A simulation scheme for temperature and precipitation changes was established for the boundary,and their contribution to the change of snowfall was quantified.The results showed that the snowfall identification method combined with the critical temperature and snowfall identification equation can better estimate the snowfall at each station in the Xilin River Basin,and the correlation coefficient is above 0.89 with an error of less than 4%.The trend of estimated snowfall between the stations in the basin is inconsistent in the Xilin River from 1980 to 2016,and the snowfall in the whole basin shows a trend of increasing eastward and decreasing westward.According to the results of Mann-Kendall mutation test,the typical mutation point of the basin was taken in 1980.and the simulation scheme of temperature and precipitation change was established.It was concluded that the temperature increase had a negative contribution to the snowfall change during the snowfall period,and the increase of precipitation contributed positively to the snowfall.The combination of temperature and precipitation will promote the increase in snowfall.