摘要
汉江流域是水土流失与洪涝灾害严重的地区。侵蚀性降雨是剧烈土壤水蚀的原动力,是洪涝灾害的直接致灾因子,因此对汉江流域侵蚀性降雨特征的研究具有重要的实践意义。利用汉江流域及其附近地区47个站点逐日降雨观测资料,采用常规统计学方法计算研究区逐年年降雨量、侵蚀性降雨量以及暴雨量平均值,进而得到降雨特征值逐年距平百分率及变异系数(Cv),分析了这3个将于特征值之间的相互关系,揭示了汉江流域降雨的时间变化特征。借助于地理信息系统技术,将汉江流域逐年降雨特征值在ARCGIS里采用Kriging方法进行空间插值,得到年均降雨特征值的空间分布,分析了研究区3个降雨特征值的空间分布特征。研究结果表明:1951-2012年汉江流域多年平均降雨量为886 mm,日降雨量≥12 mm的侵蚀性降雨量为614.1 mm,日降雨量≥50 mm的暴雨量为167.6 mm。研究期间内,3个降雨指标均在波动中下降,但下降趋势不显著,没有表现出显著的干湿趋势;年侵蚀性降雨量和年降雨量变化具有显著的一致性,但侵蚀性降雨的变化幅度大于降雨量的变化幅度;年暴雨量的变化特征与年降雨量的变化特征亦相似,但年暴雨量的波动幅度较年侵蚀性降雨量、年降雨量更大。1951-2012年汉江流域年均降雨量、侵蚀性降雨量及年暴雨量在空间上均从东南向西北递减,降雨的异常程度很高。研究结果可增进对汉江流域降雨变化规律的认识,为汉江上游植被生态恢复及中下游的防洪减灾提供参考意见。
Flood disaster and soil erosion are the most important environmental concerns in the Han River basin. Both problems are closely related to rainfall, especially erosive rainfall（≥12 mm/d）. Erosive rainfall is the driving force of severe soil erosion and is the direct cause of flood disaster. Thus the study of erosive rainfall patterns in the Han River basin has important practical significance. Daily rainfall data during the period of 1951-2012 were used to investigate the spatio-temporal variations in annual rainfall, annual erosive rainfall and annual rainstorm in the Han River basin. The data were from 47 meteorological stations in or near the study area. Conventional statistical methods were used to analysis relationships between the three rainfall indices（annual rainfall,annual erosive rainfall and annual rainstorm）. The mean annual value, anomaly percentage of every year, and variation coefficient of the three rainfall indices were calculated. Then the temporal variation of rainfall was revealed. Spatial distribution of the three rainfall indices about the 47 meteorological stations were derived by the Kriging weighting interpolation method in a GIS platform with the help of Geographic Information System（GIS） technology. The results showed that the mean annual precipitation is 886 mm, mean annual erosive rainfall（≥12 mm） is 614.1 mm, and mean annual storm rainfall（≥50 mm） is 167.6 mm in the Han River basin during the study period. The annual rainfall, erosive rainfall and rainstorm decreased over the past six decades, but the tendency is not significant. There is no significant wet-dry trend displayed. The fluctuation range of the annual rainstorm amount is more than that of the annual rainfall amount. All the three rainfall indices decreased gradually from southeast direction to northwest direction.The results can improve the understanding of the rainfall variation law in the Han River basin. It can provide a reference for the vegetation ecological construction in the upper reaches
出处
《生态环境学报》
CSCD
北大核心
2013年第9期1544-1549,共6页
Ecology and Environmental Sciences
基金
国家"十一五"科技支撑项目(2006BAC10B020)
福建省教育厅资助科技项目(JA13194)
中国博士后科学基金项目(2013M542390)
关键词
汉江流域
侵蚀性降雨
暴雨
时空变化
the Han River basin
erosive precipitation
rainstorm
spatial-temporal variation
