1961-2017年南疆地区沙尘天气的时空变化特征及影响因素分析

The spatial and temporal variation characteristics and influencing factors of dust weather in the southern Xinxiang from 1961 to 2017

利用南疆地区49个地面气象站1961-2017年沙尘资料,通过Mann-Kendall突变检验法、 IDW插值法、多元回归分析和相对贡献率等方法,对南疆地区沙尘天气的月、季和年及年代的时空变化特征及影响因素进行分析。结果表明:近57a南疆地区沙尘天气呈极显著波动下降趋势,减速为-1.06d/a,其中浮尘日数减速最大(-8.6d/10a);沙尘变化特征表现为单峰式的先增后减;沙尘暴、扬沙和浮尘日数突变年为1989、1995和1994年;沙尘天气具有季节性、区域性差异,春夏秋冬分别为31.4、20.9、11.4和6.8d,季节变化表现为春季(-4.1d/10a)最大,年内月份均表现显著减少趋势;浮尘、沙尘暴和扬沙均呈现南多北少的纬向特征,主要发生在和田和巴州地区的南部,且绝大部分站点沙尘天气呈现显著减少趋势;风速、气温日较差与沙尘天气日数呈显著正相关,对沙尘天气的相对贡献率为51.2%和13.1%,水汽压、气温、最低气温、降水量呈显著负相关,贡献率为20.4%、9.5%、0.5%和0.2%,影响排序为风速>水汽压>气温日较差>气温>最低气温>降水量,风速对沙尘天气发生的影响占主导地位。综上所述,风速、下垫面的干湿状况、气温和冷空气活动等因素是南疆沙尘天气发生的主要因素。研究成果可为南疆地区绿洲合理扩张和沙土资源利用提供科学依据。

Using the data of daily dust,sand and sandstorms from 49 ground-to-surface meteorological stations in the southern Xinjiang between 1961-2017,this study analyzed the spatial variation feature and impact factors of the annual,periods,seasonal and monthly dynamics of the occurrence days of sandstorms in the region through Mann-Kendall mutation test,IDW interpolation,multiple regression analysis and relative contribution rate,etc.The results showed that days of dust weather in southern Xinjiang in recent 57 a presented a very significant fluctuation trend,as the deceleration at-1.06 d/a;among which the deceleration of dust floating days was the largest,that was-8.6 d/10 a.Sandstorm,sand and floating dust all presented single-peak variation,they were all firstly increased and then decreased;the mutation time of the dust storm,sand and the dust days were 1989,1995 and 1994,respectively.The three kinds of duet days showed seasonal and regional differences;the number of sandstorm days occurred in spring,summer,autumn and winter were 31.4 d,20.9 d,11.4 d and 6.8 d,respectively,and the seasonal variation was the highest in spring(-4.1 d/10 a),and the monthly performance showed a significant decrease trend.Dust,sandstorm and sandstorm all presented a latitudinal feature by more in the south,less in the north,mainly in the southern part of Hetian and Bazhou;also,most of the dust weather showed a significant decrease trend.Wind speed and temperature difference presented positive correlation with the number of dust days,and their relative contribution rates to dust weather were 51.2%and 13.1%,respectively;water vapor pressure,temperature,minimum temperature and precipitation presented significant negative correlation with the number of dust days,and their relative contribution rates were 20.4%,9.5%,0.5%,and 0.2%,respectively.The order of factors were as wind speed>vapor pressure>poor daily temperature>temperature>the lowest temperature.Wind speed had a dominant influence on the occurrence of dust weather.To sum up,the occurrence of sand and dust weather in southern Xinxiang mainly depends on wind speed,dry and wet conditions of underlying surface,air temperature and the frequency of cold air activities.The research results can provide scientific basis for rational expansion of oasis and utilization of sandy soil resources in southern Xinxiang.