黄河下游河道形态变化及应对策略——“黄河下游滩区生态再造与治理研究”之一

Channel Morphology Evolution and Corresponding Coping Strategy in the Lower Yellow River——“Study on Ecological Reconstruction and Management of the Floodplains in the Lower Yellow River”(Ⅰ)

在对黄河下游河道形态演变过程以及"一级悬河""二级悬河"成因进行分析的基础上,针对宽河固堤、窄河固堤、防护堤等治理思路,认为泥沙处理是黄河下游治理的关键所在,下游滩区仍需长期发挥滞洪、沉沙作用,窄河固堤、防护堤等方案将会加剧"二级悬河"的不利态势,不利于黄河长治久安。为实现滩区"洪水分级设防,泥沙分区落淤,滩槽水沙自由交换",保障黄河下游长期防洪安全,构建黄河下游沿黄城市生态空间,推动滩区群众快速脱贫致富,实现治河与惠民双赢,在充分吸纳黄河下游河道治理成果的基础上,经论证提出了黄河下游生态治理新思路,即对滩区进行功能区划,分为生态移民安置区、高效农业区以及资源开发利用区等,利用泥沙放淤、挖河疏浚等手段,将由黄河大堤向主槽的滩地依次分区改造为"高滩""二滩"和"嫩滩",各类滩地设定不同的设防标准。

Based on the foundation of the channel form evolution process in the lower Yellow River and the analysis on the cause of formationof first-level and secondary-level suspended rivers, aiming at the issues of wide river dike fixation, narrow river dike fixation and protective embankment, the sediment dispose is the key to manage the downstream of the Yellow River. The beach area in downstream of the Yellow River still need to detent the flood and desilting for a long period. Narrow river dike fixation and protective embankment could cause the worse situation of the secondary-level suspended river which jeopardizes the safety of the Yellow River. In order to achieve the objectives of flood control and design by grades, sedimentation in separated areas and the water and sediments can be freely exchanged between beach and channel in the floodplain area, guarantee the flood control safety in the downstream of the Yellow River, build the ecological space of the cities along the river, promote the development of floodplain area and achieve the success both in river management and the people＇s benefits, on the base of absorption of the results from the management of the river, a new method of the ecological management in downstream was proposed, which was to divide the floodplain area into different functions, such as resettlement area for the ecological immigrant, effective agriculture area and resources development and utilization area, with the methods of sediment elimination and dredging the river, to improve the main channel into high beach, second beach and tender beach with diverse flood control standards.