太湖水网地区河网调蓄能力分析

平原地区一般河网密度高,河道比降小,水流流泄不畅,极易造成内涝灾害.但由于河流众多,水面面积大,河网的调蓄能力也相当可观.以太湖流域1991年特大洪涝灾害为例,采用河道非恒定流的计算方法,分析太湖河网的调蓄水量.经计算表明,太湖流域的河网调蓄水量约为太湖调蓄水量的50%,对缓解太湖洪涝灾害起着重大的作用

ANALYSIS OF THE STORAGE CAPACITY OF RIVER NETWORK IN TAIHU WATERSHED

In the plain area, because of the channel density is large and the slope of riverbed is small, the channel flow is slow and the waterlogging often occurs. But the channel density and the water area is large, the storage capacity of river network is large. In this paper, a model for the storage of river network calculated by the mathematical model of unsteady flow in open channels is established as an example for the flooding and waterlogging in Taihu in 1991. In the model, we simplify the Taihu river networkas 419 rivers, 267 net nodes and 13 lakes. After simulating all net node water levels with the Taihu rivers network calculation model, storage of all the simplified rivers is calculated. Because the simplified rivers can't exactly express all the rivers capacity of flow and the capacity of storage in Taihu,two concepts, the land width and the coefficient of river width, are introduced in to river network simulation. Calculated by the model, the storage of the river network in Taihu watershed is about 50% of the Taihu Lake. It is important to reduce damage of the flooding and waterlogging in Taihu watershed.