渭河下游河道输水能力与断面形态响应关系研究

Study on water conveying capability of channel and its response relationship to morphology of cross-sections in the Lower Wei River

渭河下游河道冲淤幅度大,各断面形态变化情况复杂,导致其平滩流量也剧烈变化。本文在分析沿程床沙组成、不同年代断面形态实测资料的基础上,概化不同河段不同年代河道的糙率、比降,探索提出了滩唇比降法计算断面的输水能力方法,所得结果与传统的水文站经验方法吻合较好,说明该方法是研究沿程不同河段输水能力的一种新的途径。对比分析得到渭河下游河道平滩面积与平滩流量具有指数关系的特点,深入分析了不同年代平滩流量与断面形态的影响关系变化规律。

Due to serious aggradation and degradation in channels, and due to complicated changes of cross-sections morphology, distinct changes of bank-full discharge occur in the Lower Wei River. Based on analysis of large amounts of field data, including the composition of bed materials and observed cross- sections morphology in past decades, generalized calculations were conducted for Manning＇ s roughness coefficients and longitudinal slopes of different reaches in different periods, a calculation method to determine the water conveying capability of the main channel by considering bench-slope along the Lower Wei River has been worked out. The results with this method agree well with observed data. Furthermore, the occurrence of bank-full discharge in several sections in different years is analyzed and the response relationship between cross-section morphology and water conveying capability is discussed.