气候变化对内蒙古牧区白灾的影响——基于熵权法分析的锡林浩特市案例研究

Influence of climate change on heavy snow disaster in pastoral area of Inner Mongolia: an entropy-weighted technique-based case study on Xilinhot City

锡林浩特位于内蒙古牧区锡林郭勒盟中东部,由于自然条件和社会因素,其畜牧业发展受白灾影响较大,所以在全球变暖的大环境下,研究气候变化对锡林浩特白灾的影响是很有必要的。基于对研究区近几十年内发生的白灾事件的分析,选取了6个评价白灾的气候指标:冬季降水量、积雪持续时间、低温容易掉膘期的负积温、5日温差≥12℃日数、积雪期大风日数和牧草生长季降水量,并利用国家气候中心提供的地面气象资料月报和锡林浩特牧试站数据,计算了这6个因子的长期变化趋势,表明冬季降水和低温容易掉膘期的负积温有增加的趋势,同时积雪期大风日数有减小趋势。文章还引入熵权法,计算了各因子对白灾影响的重要性程度,从而建立了综合评价方法,用以分析白灾随气候变化的变化规律。结果表明,在现有气候变化条件下,白灾有减轻的趋势。

Xilinhot City is located at the central area of Xilingol League, of which animal husbandry is affected by heavy snow disaster seriously, so researches on influence of climate change on heavy snow are necessary under the condition of global warming. Six meteorological indices were selected to estimate heavy snow based on analysis of heavy snow events happened in the last several decades. Using data from National Climate Center and Xilinhot Stockbreeding Experimental Station, precipitation in winter and negative accumulated temperature when daily mean temperature below 5℃ were found to be increased, and index of days of mean daily wind speed above 6m/s when snow covers was to be decreased. Entropy-weighted technique was adopted to calculate weight coefficients of selected indices, and estimation was made to analyze action of climate change on heavy snow. It is found that heavy snow have a lessening trend.