淮河中上游流域洪水主要类型及其时空分布特征

洪水过程相似性挖掘对流域雨洪资源利用、水库防洪调度以及河流生态修复等具有重要的现实意义。论文以淮河中上游流域16个水文站2006—2015年125场洪水过程数据为基础,采用洪水量、时间、变化率和形态等特征指标对完整洪水过程进行了全面刻画,以主成分分析和层次聚类等多元统计分析手段辨识了流域内代表性洪水类型,揭示了各洪水类型的时空分布特征。结果表明：① 淮河中上游流域主要有5类代表性洪水类型,分别为长历时且变化剧烈型、多峰长历时型、尖瘦短历时型、矮胖型以及常规型。② 从时间分布来看,2006—2015年间洪水类型数量呈现减少趋势,常规型洪水的比例逐渐增大;丰水年份(如2007年)、平水年份(如2006年)的洪水类型较多,而枯水年份(2011—2013年)洪水类型较少,以常规型和矮胖型洪水出现频率居多。③ 从空间分布来看,源头站点的洪水类型较多,中下游站点的洪水类型比较单一,主要从尖瘦型洪水过程逐渐转变为矮胖型,这与流域内水源涵养能力、工程调蓄能力以及降水多样性等有较大的关系。研究可为流域洪水信息挖掘和特征分析等提供参考借鉴,也可为淮河流域洪水的演变特征分析、水库防洪调控和雨洪资源利用等提供决策依据。

Characteristics of main flood event types and their temporal-spatial variations in the upper and middle reaches of the Huai River Basin

Flood similarity identification has important practical significance for floodwater utilization, flood control of reservoirs, and river ecological restoration. In this study, the observations of 125 flood events at the 16 hydrological stations in the middle and upper reaches of the Huai River Basin from 2006 to 2015 were collected, and the metrics of flood magnitude, timing, and rate of changes and patterns were adopted to characterize the entire flood events. Multivariate statistical analysis—principal component analysis and hierarchical clustering method—were adopted to identify the representative flood event types. Finally the temporal and spatial distributions of each flood event type were identified. The results show that: 1) there are five types of representative flood events in the upper and middle reaches of the Huai River Basin, including long duration and extreme variability type, multiple peaks and long duration type, thin and short duration type, fat and short duration type, and conventional type. 2) From the perspective of temporal distribution, the number of flood event types showed a decreasing trend during 2006-2015, and the proportion of conventional floods gradually increased. More flood event types were found in the high flow years ( e.g. 2007) and normal flow years ( e.g. 2006), and fewer types were in the low flow years (2011-2013) with high frequency of conventional and fat and short duration flood event types. 3) From the perspective of spatial distribution, many flood event types appeared at the source regions, and the flood event types at the middle reaches and downstream regions were relatively few. The flood event type of thin and short duration gradually changed to fat and short duration due to the increased water source conservation capacity, reservoirs' storage capacity, and precipitation diversity in the basin. The study provides some reference for flood information mining and characteristics analysis at the basin scale, and provides scientific foundations for decision makers in flood event analysis, reservoir flood control, and floodwater utilization in the Huai River Basin.