2012—2023年喀什地区暖季分级短时强降水时空分布特征

Analysis of Temporal and Spatial Distribution Characteristicsof Classified Short-term Heavy Rainfall in Kashgar Region

摘要:

利用2012—2023年4—9月喀什地区178个气象站逐时降水资料，采用统计方法分析了喀什地区不同量级短时强降水时空分布特征。结果表明：喀什地区短时强降水频次的空间分布总体呈北部＞南部＞东部、浅山区＞平原地区的特征。地形与短时强降水关系密切，短时强降水主要发生在山前迎风坡、峡谷、地形陡升区、喇叭口地形、绿洲与戈壁沙漠交界区域等复杂地形附近。短时强降水发生频次年际变化大，2016—2018年短时强降水高发，2017年出现频次最多（155次），2012年最少；各量级短时强降水频次年变化特征与总频次大致相同，频次最大值均出现在2017年。月、旬发生频次变化均呈单峰型，7—8月为短时强降水高发期，其中7月中旬累计频次达最高（140次），雨强最大值出现在8月上旬（87.9 mm/h）。日变化呈双峰型，傍晚前后至前半夜发生频次最高、后半夜至早晨的次之、上午至中午时段的最低；19时至夜间01时为不同量级短时强降水的高发时段。

Abstract:

Based on hourly precipitation data from 178 meteorological stations in Kashgar Region from April to October in 2012-2023,the temporal and spatial distribution characteristics of short-term heavy rainfall of different grades are statistically analyzed. The results shows that:the frequency of short-term heavy rainfall in Kashgar region distributed in the pattern of north > south>east,shallow mountain area more then plain area.The terrain is closely related to short-term heavy rainfall.The short-term heavy rainfall mainly occurred near the complex terrain, such as the windward slope in front of the mountain, the valley, the steep terrain, the horn estuary terrain, and the junction area between oasis and Gobi desert..The inter-annual variation of short-term heavy rainfall is very different.2016-2018 is the year with the highest frequency of short-time heavy rainfall, with the highest frequency in 2017 (155 times) and the lowest frequency in 2012 (10 times). The annual variation characteristics of short-time heavy rainfall frequency of different grades are roughly the same as the total frequency, and the maximum frequency all appeared in 2017. The frequency changes of monthly and ten-day periods are unimodal. The high-frequency period of short-term heavy rainfall occurred from July to August, and the cumulative frequency reached the highest (140 times) in mid-July, while the maximum of extreme rainfall intensity appeared in early August (87.9 mm/h). The diurnal variation shows a bimodal pattern, with the highest frequency from around evening to midnight, followed by from midnight to morning, and the lowest from morning to noon: from 19:00 to 1:00 PM were the high frequency periods of short-time heavy rainfall of different magnitudes.