粤东地区近42 a降水序列时空变化特征分析

Analysis of Temporal and Spatial Variation Characteristics of Precipitation Series in Eastern Guangdong in Recent 42 Years

以70个雨量站点近42 a降水资料为基础,采用线性趋势、累积距平法、Mann-Kendall突变检验、滑动T突变检验、小波分析和时态GIS等方法,对粤东地区降水特性进行分析。结果表明:降水呈现丰枯交替变化过程,且总体均呈微弱的减少变化;年降水和汛期降水系列在2019年发生突变,并呈现出偏多向偏少变化,非汛期降水无明显的突变年;年降水、汛期降水和非汛期均处于偏枯期;年降水和汛期降水的主周期均为15 a,次周期为4 a、8 a和24 a,非汛期降水序列的主周期为16 a,次周期为3 a、5 a、7 a和28 a;不管是丰水还是枯水年,该地区降雨空间分布特征均为北多南少,即北部山地丘陵地带降雨多,沿海地带降雨少,没有明显随时间节点不同和丰枯变化而产生降水空间分布变化。

Based on the precipitation data of 70 rainfall stations in the past 42 years, the characteristics of precipitation in eastern Guangdong were analyzed using methods such as linear trend, cumulative anomaly method, Mann-Kendall mutation test, sliding T mutation test, wavelet analysis and temporal GIS. The results show that: the precipitation presents an alternating process of high and dry seasons, and the overall decrease changes slightly;the annual precipitation and the flood season precipitation series have abrupt changes in 2019, and show a change from more to less, and there is no obvious abrupt change in non-flood season precipitation. Annual precipitation, precipitation in flood season and non-flood season are all in the dry season;the main cycle of annual precipitation and precipitation in flood season are 15a, the sub-cycles are 4a, 8a and 24a, the main cycle of non-flood season precipitation sequence is 16a, the sub-cycle is 3a, 5a, 7a and 28a;whether it is a wet year or a dry year, the spatial distribution of rainfall in this area is more in the north and less in the south, that is, there is more rainfall in the northern mountainous and hilly areas, and less rainfall in the coastal areas, and there is no obvious difference with time nodes. changes in the spatial distribution of precipitation.