Application of Comprehensive Fall Index Method in Water Level-Flow Relation of Main Cross Sections in Middle Reaches of the Yangtze River

摘要

The Yangtze River, the longest river in China, is also a famous river in the world. Most regions within its drainage basin are of moderate climate, abundant rainfall, rich resources and dense population, in the meantime, the Yangtze River basin is also a region in which floods frequently happens. In order to launch studies on flood control impact in the middle reaches of the Yangtze River better, this paper selected stage-discharge data of the main fracture surfaces of three control stations-Shashi, Luoshan and Hankou located on middle reaches of the Yangtze River during flood period (from May to September) during 1981～2010, based on analysis of influencing factors on water level-flow relations in three hydrologic sections, it adopted comprehensive fall index method to process these data, by which it obtained the achievement of water level-flow relation curves in these stations, and used principle of least squares to conduct curve fitting and then made a reasonable analysis. Results show that polynomial curves fitting can eliminate the influence of calculated water level-flow relation line to the least, and it has better effect in practical application.