基于降雪识别的1951—2020年京张地区降雪演变趋势分析

Analysis on the evolution trend of snowfall in Jing-Zhang area from 1951 to 2020 based on snow identification

【目的】为研究京张地区极端气候变化规律和趋势,【方法】选取1951—2020年北京、张家口两市4个气象站的降水数据,通过参数化降雪识别的方法得到降雪数据,采用气候倾向、非参数M-K突变检验、相关分析等方法,研究降雪量、降雪天数的年际变化特点,【结果】结果表明:(1)大雪和极端大雪发生在初冬的概率最高,初春降雪天数最多,导致降雪量在11月和2—3月较大;(2)小雪降雪量减少导致城区站点降雪量呈减少趋势,大雪和极端降雪量的增加导致山区站点降雪呈增加趋势;(3)由于小雪降雪天数降低,京张地区的降雪天数呈减少趋势,其中城区变化趋势比山区更为明显;(4)降雪天数与降雪年内平均相对湿度、平均最高温度相关性较高,其中,城区站点的温度对降雪天数的影响高于湿度,在山区则相反。【结论】该研究可为京张地区冬季降水预测、冰雪气候资源评价及配置提供参考。

[Objective] In order to study the regulation and trend of extreme climate change in Jing-Zhang area, [Methods]precipitation data of four meteorological stations from 1951 to 2020 in Beijing and Zhangjiakou are selected, and snowfall data are obtained by the method of parametric snowfall identification. The interannual variation characteristics of snowfall amount and snowfall days are studied by means of climate tendency, nonparametric M-K test, correlation analysis, etc. [Results] The results show that:(1) the probability of snowfall and extreme snowfall in early winter is the largest, and the number of snowfall days in early spring is the largest. November and February-March are relatively large;(2) the decrease of slight snow amount leads to a decrease of snowfall amount in the urban area, and an increase in heavy snow and extreme snowfall leads to an increase in snowfall in mountainous areas;(3) as the number of slight snow days decreases, the number of snowfall days in Beijing and Zhangjiakou area shows a decreasing trend, and the changing trend in the urban area is more obvious than that in the mountainous area;(4) the number of snowfall days has a strong correlation with the average relative humidity and average maximum temperature in the snowfall year. The influence of temperature on the number of snowfall days in urban sites is higher than that of humidity, but the opposite is true in mountainous areas. [Conclusion] This study can provide a reference for winter precipitation forecast, ice and snow climate resources evaluation and disposition in Jing-Zhang area.