2016年长江中下游干流高水位成因及特点 Analysis of the Reason and Characteristics of the High Water Level in the Middle and Lower Reaches of Yangtze River in 2016

2016年7月长江流域发生中下游型区域性洪水，为1999年以来最大洪水。形成本次高洪水位的主要原因有流域前期来水偏丰、来水集中且干支流遭遇严重、下游顶托宣泄不畅、江湖关系改变以及河道冲淤造成的水位流量关系变化等因素。本文以长江干流螺山、汉口及大通站为例，对各站断面形态和水位流量关系变化进行了定量的分析，并与1996年洪水特征进行比较。 Regional flood occurred in the middle and lower reaches of Yangtze River in 2016 is the largest flood since 1999. The reasons for this flood include abundant precipitation in the first half year, flood of the tributary encountering with each other, downstream jacking, changed river-lake relation and stage-discharge relation caused by channel deposition and erosion and other human factors. Luohan, Hankou and Datong are taken as examples to analyze the change of cross section morphology and stage-discharge relation, and the results are compared with those of the flood in 1996.