喀什市能见度的变化趋势及未来预测

Change Trend and Prediction for Future of Visibility in Kashgar City

通过对喀什市能见度资料的整理和分析,运用趋势分析法、Mann-Kendall法、R/S分析法和等级分类法研究了1973—2012年喀什市能见度的年际、年代变化特征,并对其未来发展趋势进行了预测。结果表明,喀什市在1973—2012年能见度在持续降低,且年平均能见度和四季能见度在21世纪初达到最低;5种不同等级能见度发生日数中,2级能见度天气日数呈增加趋势,1级、3级能见度日数呈减少趋势,4级和5级能见度日数仅在20世纪70年代出现,之后发生日数为0;春季、秋季、冬季的能见度和2级、1级能见度日数都发生了明显的突变,年平均能见度、夏季能见度和3级能见度日数都没有明显的突变;2级能见度日数将来会持续增加,3级能见度日数会持续减少,四季能见度将会持续变差,1级能见度发生日将会由过去一段时间的持续减少转变为将来的持续增多。

Based on meteorological data of Kashgar city from 1 973 to 2010 and trend analysis,Mann-Ken-dall method and classification method,the interannual,seasonal and decadal changes of visibility of Kashgar city were analyzed,and the future trend was predicted by R/S analysis method in this paper.Results showed that the visibility of Kashgar city has consistently come down and the annual average visibility and four seasonal visibility reached the minimum in early 21 century;the days of second level visibility had sig-nificantly increased.The days of fourth and fifth level occurred in the 1 970s only and the days of first and third level visibility had significantly declined and the days of first and third level visibility only occurred in 1 970s;the days of second level visibility will increase consistently and the days of third level visibility will decrease consistently and the days of first level visibility will be transformed from consistent decrease to sustained increase;the visibility of four seasons will be worse in the following several years.