近10年长江中游重点险工段近岸河床冲淤演变特点分析

Evolution Characteristics of Near-bank Riverbed Erosion and Deposition in Vulnerable Sections of Middle Yangtze River over the Past Decade

险工段是河道岸坡易崩段,是长江防洪体系的薄弱环节,险工段近岸河床演变直接关乎沿江堤防稳定和防洪安全。根据近10 a来长江中游重点险工段观测成果,研究了险工段近岸河床冲淤演变特点及水沙条件、整治工程、土体组成等对险工段河床演变的影响。结果表明,整治工程实施对保障险工段近岸河床稳定具有显著作用,岸坡趋于稳定是长江中游重点险工段演变的总体规律。受局部河势调整影响,仍有1/3左右的险工段近岸河床存在冲刷趋陡的现象,需加强观测并采取相应守护措施。研究成果对研判长江中游重点险工段岸坡稳定发展趋势、优化险工段观测位置布设具有重要意义。

Vulnerable riverbank slopes are prone to collapses and thus represents weak links of the Yangtze River flood control system.The evolution of vulnerable riverbank slopes directly impact levee stability and flood control safety.Based on a decade of observations of vulnerable sections of the middle reach of Yangtze River,we investigate the evolution patterns of vulnerable riverbank slopes and explore how water and sediment conditions,regulatory projects,and soil composition influence riverbed dynamics.Findings reveal that river regulation projects notably influence the stability of the near-bank riverbed,with a tendency towards bank slope stabilization being a prevailing trend.However,approximately one-third of the vulnerable sections exhibit a continued erosion steepening,attributed to local river regime adjustments.Vigilant monitoring and corresponding protective measures are thus imperative.These research outcomes hold significant implications for analyzing and projecting the development trend of key riverbank sections in the middle reach of Yangtze River and optimizing observation site layouts for these critical sections.