江西省汛期降水集中度和集中期时空分布特征

利用1961—2021年汛期（4—6月）江西省83个气象站点的逐日降水序列资料，计算了江西省汛期候尺度降水集中度（PCD）和集中期（PCP），运用合成分析、趋势分析方法分析了江西省汛期降水的不均匀特征。结果表明：江西省PCD的变化区间为0.12—0.43，PCP的变化区间为5月第1候至6月第5候，说明江西省汛期降水较为均匀，但近年来降水有更集中的趋势。在空间分布上，赣南南部和赣北东部降水较为集中，降水集中期自南向北逐渐推迟，主要出现在6月中下旬。从变化趋势来看，PCP在赣南南部和赣中东部为偏早趋势，赣中北部和赣北地区有偏晚的趋势，PCD的趋势并不明显。多雨年PCD大值区主要在赣中地区，最大降水出现在6月；少雨年PCD大值区在赣北中南部和赣南东部地区，最大降水出现在5月。

Spatial and temporal characteristics of precipitation in flood season in Jiangxi province based on precipitation concentration degree and concentration period

Based on the daily precipitation data of 83 stations in the flood season ( April-June ) from 1961 to 2021 in Jiangxi province, the pentad scale precipitation concentration period (PCP) and concentration degree (PCD) in the flood season were calculated. The spatio temporal characteristics of precipitation in the flood season were discussed by composite analysis, trend analysis and Mann Kendall mutation test. The results showed that the PCD in Jiangxi varied from 0.12-0.43, and the PCP from 7-17, indicating that the precipitation in Jiangxi was relatively uniform in flood season, but presented a more concentrated trend in recent years. The precipitation in southern and eastern Jiangxi was concentrated, and the precipitation concentration period was gradually delayed from south to north, mainly in the middle and late June. PCP in southern and eastern Jiangxi exhibited early trends, northern and northern Jiangxi presented late trends, and the trend of PCD was not obvious. The areas of large PCD values in rainy years were mainly concentrated in central Jiangxi, and the maximum precipitation occurred in June. The areas of large PCD values in the less rainy years were in the central and southern part of northern Jiangxi and the eastern part of southern Jiangxi, and the maximum precipitation occurred in May.