1981-2016年雅鲁藏布江流域风沙日数时空变化特征分析

Analysis of spatiotemporal variation characteristics of wind-sand days in the Yarlung Zangbo river basin during 1981-2016

利用1981-2016年雅鲁藏布江流域11个气象站大风、浮尘、扬沙和沙尘暴日数观测资料,分析风沙日数的时空变化特征。结果显示:雅江流域风沙日数以大风为最多,其次是扬沙和沙尘暴,浮尘最少。流域内有两个风沙天气的高值区,一个位于上游的拉孜,另一个位于中游的浪卡子,年风沙日数都在50天以上;近36a年雅江流域风沙日数明显减少(11.2d/10a),且呈逐年代减少趋势;风沙日数春季减幅最大,其次是冬季;冬季降水量与风沙日数为正相关,其他时段年、季平均气温和降水量与风沙日数反相关。雅江流域气候的暖湿化趋势,在抑制大风、扬沙和沙尘暴天气的同时,又使浮尘天气有所增多。

The temporal and spatial variation characteristics of wind and sand day were analyzed by using the observation data of 11 meteorological observation stations in the Yarlung Zangbo river basin during 1981-2016.The results showed that： the gale days occurred the most in the Yarlung Zangbo river basin; blowing sand and dust storm days were the second; dust days were the least. There are two high value areas of wind and sand weather in the Yarlung Zangbo River basin： Lazi in the upper reaches,Langkazi in the middle reaches. Where the number of wind and sand days were more than 50 days. The number of wind and sand days in the last 36 years were significantly reduced（ 11. 2 d/10 a）,and the trend was decreasing decanally. The reduce of wind and sand day was the most in spring,followed by winter. Precipitation in winter was positively correlated with wind and sand days. For other seasons the air temperature and precipitation were negatively correlated with wind and sand days. The trend of warm and humid climate in the Yarlung Zangbo river basin can restrain the wind,blowing sand and dust storm,but can increase the dust weather.