以降低洪水位为目标的河道疏浚规模与效果研究

疏浚作为一种清淤工程措施在河道治理、水库库容恢复、航道和港池维护、河湖污染物移除等方面得到广泛应用.由于担心疏浚后发生回淤,疏浚效果不能长期维持,疏浚很少作为一种工程措施在河道防洪治理得到应用.然而,在流域来沙大幅减少的背景下,对河道实施一定规模的疏浚以扩大行洪能力,不仅是可能的,而且不会发生严重回淤,疏浚效果可以长期...

Study on scale and effect of river dredging aiming at reducing flood level

As an engineering measure,dredging has been widely used in river regulation,reservoir capacity restoration,channel and harbor basin maintenance,river and lake pollutant removal,and so on. Due to the worry of siltation after dredging,the dredging effect cannot be maintained for a long time,and dredging is rarely applied as a measure in river flood control. However,under the background of significant reduction of sediment inflow in the basin,it is not only possible to implement a certain scale of dredging to enhance the flood-conveying capacity, but also there will be no serious siltation, and the dredging effect can be retained for a long time. In this paper,the scientific and technical problems such as how to demonstrate the effect of dredging on improving flood control capacity and how to determine reasonable dredging scale are studied. The single factor relationships for main hydraulic and cross section factors with discharge or flow depth are established, which greatly simplifies the calculation formula and improves the ability of solving practical problems. The calculation formulas of reducing flood level and increasing flood-conveying capacity by dredging are deduced, and the technical method of determining the reasonable dredging scale of river channel is put forward. Based on the basic data from Songhua River and Huaihe River, a case study is designed to demonstrate the effect of dredging on reducing flood level and determine the reasonable dredging scale. The research results could provide a theoretical basis for evaluating the effect of dredging on improving flood control capacity and dredging design.