基于SPEI的1960—2018年赣江流域干旱特征

基于赣江流域39个气象站点逐月降水和气温数据,计算不同时间尺度标准化降水蒸散发指数(SPEI),采用Mann-Kendall突变检验、主成分分析(PCA)等方法,分析了赣江流域1960—2018年干旱时空变化特征.研究表明:不同时间尺度SPEI均有微弱升高的趋势,干旱形势有所缓解,SPEI能够较好地表征赣江流域旱涝情况.赣江流域中部的轻旱和特旱发生频率要高于其他地区,中旱主要高发地区主要分布在南部和西部区域,重旱主要集中在东部和北部.赣江流域干旱的空间分布具有较好的一致性,旱涝变化整体保持一致,南部与北部旱涝状态存在相反的纵向差异,且中部与南部、北部旱状况涝存在空间差异.

Drought characteristics in Ganjiang River Basin from 1960 to 2018 based on SPEI

Based on the monthly precipitation and temperature data of 39 meteorological stations in the Ganjiang River Basin from 1960 to 2018, the standardized precipitation evapotranspiration index (SPEI) was calculated at different time scales. Using run length theory, Mann Kendall mutation test, principal component analysis (PCA) etc., the spatial and temporal variations of drought in the Ganjiang River Basin during 59 years were analyzed. The results showed that the SPEI on different time scales presented a slight upward trend, and the drought situation had eased. The SPEI can better represent the drought and flood situation in the Ganjiang River Basin. The frequency of light and extreme droughts in the central part of the Ganjiang River Basin was higher than that of other regions. High incidence of moderate droughts was mainly distributed in the southern and western regions, and severe droughts were mainly concentrated in the eastern and northern regions. The first principal component was manifested as the spatial consistency of dry and wet changes in the basin, the second principal component was manifested as the spatial difference between north and south, and the third principal component was manifested as the difference between the central and north south.