1961—2021年托里县汛期暴雨日数气候特征分析

Climatic Characteristics of Rainstorm Days in Flood Season in Toli County from 1961 to 2021

文章基于1961—2021年托里县国家气象站及2012—2021年6个区域气象站5—9月降水资料,采用线性趋势、M-K突变检验、Morlet小波分析等方法,分析了托里县汛期暴雨时空变化特征。结果表明:托里县国家气象站和区域气象站汛期暴雨日数均呈增加趋势,但增加趋势不显著。两类站点暴雨分布具有差异性,国家气象站暴雨日数月际变化与区域气象站暴雨日数主要出现在5—8月的分析结论基本一致,但与区域气象站峰值出现在8月不一致;旬变化也与区域气象站暴雨日数主要出现在7月上旬、8月中旬结论不一致;暴雨空间分布也具有明显的地域性,暴雨最多出现在西南部山区,最少在东北部山前平原,特别是高海拔山区更容易出现暴雨,说明托里县暴雨受地形影响明显,以突发性和局地性暴雨为主。区域气象站可以更加精细地监测到复杂地形下暴雨变化,对今后开展气象预报预警服务及布设区域观测站网有较大参考价值。

Based on the precipitation data from May to September of Tori national meteorological observing station during 1961-2021 and six regional meteorological observing stations during 2012-2021, the article analyzed the temporal and spatial variation characteristics of heavy rainfall in Tori County during flood season by using linear trend, M-K mutation test, Morlet wavelet analysis, etc. The results showed that the number of rainstorm days in Tori had an indistinctively increasing trend, and the rainstorm distributions of the two types of stations were different. The number of rainstorm days of national and regional meteorological observing stations mainly occurred from May to August, but only the peak of regional meteorological observing stations occurred in August. In terms of ten-day variation, the rainstorm days at regional meteorological stations mainly appeared in early July and mid-August, while that at national meteorological stations did not. The spatial distribution of rainstorm was obviously regional.Rainstorms occurred mostly in the southwestern mountainous area, especially in the high-altitude mountainous area, and occurred least in the northeastern piedmont plain. It indicated that the rainstorm in Tori was affected by the topography obviously, with sudden and localised rainstorm predominating. The regional meteorological observing stations could monitor the changes of rainstorm under complex terrain more precisely, which had important reference value for developing meteorological forecast and early warning services and building regional observing stations in the future.