嘉陵江西汉水流域水沙关系诊断与变异特征分析

Water-sediment of relationship diagnosis and variation characteristics analysis in Xihan River of Jialing River basin

径流、泥沙是影响河势稳定的主要因素,与河道冲淤变化密切相关,水沙关系分析是一项基础性研究工作。为了对西汉水流域水沙关系进行变异特征分析,本文在收集西汉水下游控制站镡家坝站径流量、输沙量、降水量的基础上,采用Mann-Whitney法、皮尔逊(Pearson)相关系数法、模比系数差积曲线法和时序累积值相关法对该流域水沙关系进行诊断及变异特征分析。结果表明:夏季径流量和输沙量的占比最高,秋季次之,春、冬两季贡献率最小,季节性的水沙变化表现出分布不均匀的特征,以夏、秋两季最为集中;水沙丰枯同步性较好;序列在1993年出现转折,转折后相关性弱于转折前;降水量对径流量、输沙量的影响在逐年降低,人类活动的影响逐年上升。本次研究,对掌握西汉水流域水文特性、区域水资源规划具有重要意义,为水资源合理利用提供数据支持。

Runoff and sediment are the main factors affecting the stability of river regime,which are closely related to the changes of erosion and deposition,the analysis of water-sediment relationship is a basic research work.In order to analyze the variation characteristics of the water-sediment relationship in the Xihan River basin,this paper,based on the collection of runoff,sediment transport and precipitation at Ganjiaba Station,a control station in the lower reaches of the Xihan River,uses Mann-Whitney method,Person correlation coefficient method,modulus ratio coefficient difference product curve method and time series cumulative value correlation method to diagnose the water-sediment relationship and analyze the variation characteristics.The results show that:The proportion of runoff and sediment transport in summer is the highest,followed by autumn,and the contribution rate in spring and winter is the lowest.Seasonal changes of water and sediment show the characteristics of uneven distribution,with summer and autumn being the most concentrated;The synchronization of water abundance and drought is good;The sequence turned in 1993,after which the correlation was weaker than before;The impact on runoff and sediment transport is decreasing year by year,while the impact of human activities is increasing year by year.This study is of great significance to master the hydrological characteristics of the Xihan River basin and regional water resources planning,and provides data support for the rational use of water resources.