摘要
利用西江流域122个气象台站1971—2015年汛期逐日降雨量资料,采用泰森多边形法计算西江22个子流域逐日面雨量,然后应用趋势分析、M-K突变检验、合成分析等方法,对西江全流域和子流域汛期年、旬平均暴雨面雨量、日数和强度时空分布特征及趋势变化和突变前后空间分布特征进行分析。结果表明:(1)常年平均暴雨面雨量、日数和强度呈东多(前)西(弱)少的分布,极大值在东部子流域,极小值在西部子流域;暴雨面雨量和日数前汛期多、后汛期少,强度汛初弱、汛中后期强,暴雨日东北部最早开始,西部最早结束,强暴雨区东部最早出现,西南部最迟结束。(2)旬平均暴雨面雨量和日数呈单峰型分布,峰值和次峰值出现在6月上中旬,强度呈波动增减分布,4月上旬最弱,6月中旬最强。(3)近45 a来西江流域暴雨面雨量、日数和强度呈上升趋势,其中强度上升趋势显著;暴雨面雨量、暴雨日数和强度在1992年出现一次明显的突变,突变后,中东部子流域为增加(或增强),西部、南部和北部的部分子流域为减少(或减弱)。
Using daily precipitation data at 122 meteorological stations from 1971 to 2015, the Tyson polygon method was used to calculate the daily rainfall in 22 sub-watersheds in the Xijiang river basin. The temporal-spatial distribution characteristics and its mutation characteris-tics of the ten-day average rainstorm areal rainfall, torrential rain days and the rainfall intensity were investigated by means of synthetic anal-ysis, trend analysis and Mann Kendall method. The results indicate that （1）the rainstorm areal rainfall, torrential rain days and the rainfall in-tensity in the Xijiang river basin showed a similar spatial distribution in the past 45 years, which was larger in the eastern Xijiang river basin than in the west. The maximum value was in the eastern part of sub-watersheds, and the minimum value was in the western sub-watersheds. The rainstorm areal rainfall and the torrential rain days were larger in pre-flood season than in late flood season, while the rainstorm intensity was stronger in mid-late flood season than in pre-flood season. The torrential rain days first appeared in the east-northern part of Xijiang riv-er basin, and first ended in west. The heavy rainstorm area first appeared in the eastern part of Xijiang river basin, and first ended in south-west. （2） The ten-day rainstorm areal rainfall and the torrential rain days showed a single peak distribution, with the peak and sub-peak in early to middle of June. However, the trend of rainstorm intensity showed a fluctuation, with the weakest in early April and the strongest in mid-June. （3） In the past 45 years, the rainstorm areal rainfall, torrential rain days and the rainfall intensity showed an increasing trend, espe-cially for the rainfall intensity. But a significant mutation occurred in 1992. After the mutation, the mid-eastern sub-watersheds were in-creased （or enhanced）, part of the western, southern and northern sub-watersheds were reduced （or weakened）.
出处
《暴雨灾害》
2018年第1期24-31,共8页
Torrential Rain and Disasters
基金
广西科学研究与技术开发计划项目(1598017-15)
国家自然科学基金(41575051)
广西自然科学基金(2016GXNSFAA380330)
广西气象局气象科研计划重点项目(桂气科201503)
关键词
西江流域
汛期
暴雨面雨量
时空分布
Xijiang river basin
flood season
the rainstorm areal rainfall
temporal and spatial distribution
