基于洪涝灾害控制目标的河网结构-调蓄能力情景模拟研究

Scenario Simulation of River Network Structure and Storage Capacity Based on Flood Control Objectives

采用SOBEK软件平台构建平原河网模型,模拟不同情景下河网结构变化对河网削减洪峰能力的影响,尝试找到能够有效调控洪峰的河面率范围和河网结构参数。研究表明,在不改变河面率的情境下,支流的交汇角度小,交汇点在干流上游时河网削减洪峰能力相对较大;在提高河面率的情境下:随河流弯曲度增大调蓄能力增大,当弯曲度为2.8时河流单位面积削减洪峰的能力达到峰值;随河面率增大河网削减洪峰能力增强,但单位河面积削峰效率存在峰值,模拟得出河面率为3%～5%时,单位河面积增量的削峰效率最强;增加支流面积比增大干流面积能更有效地改善河网的调蓄功能。

Using SOBEK model, a hydraulic model for river network plain is established, which is used to simulate storage capacity under differen! scenario by designing different sorts of river network structures, and the reasonable range of river channel area and river network structure parameters that might decrease the flood peak effectively are tried to be found. Resuh＇~ show that, with scenario of keeping the same ratio of river channel area, for a selected monitoring point in mainstream, tributary in upstream is more effective in decreasing flood peak compared with that in downstream, the more smaller of intersection angle of tributaries, the more stronger capacity in controlling flood. With scenario of increasing the river channel area, river storage and control capacity enhanced with the increasing of fiver curvature, a：ad the per-unit capacity of the river area reaches the peak value when fiver curvature is 2. 8. River storage and con：rol capacity enhanced with the increasing of river channel area but there is a peak value. When the ratio of fiver channel area is between 3% and 5% , the increasing of per fiver area unit has the best affection in decreasing peak flow. To increase tributary area might improve the fiver network storage and flood control capacity more effectively than to increase the mainstream area.