洪泛区林地的开发对鱼类栖息地面积的影响模拟

洪泛区的开发利用,必然会导致洪泛区林地糙率的改变。河漫滩也是河流洪泛区的一部分。洪泛区糙率的减小,会使河水流速增大,从而减小鱼类可用栖息地面积。因此,在洪水发生时,为了给鱼类提供避险场所,保护有效栖息地面积,需研究洪泛区林地的开发对鱼类的影响。利用River 2D软件模拟在一定频率的洪水条件下,不同的河漫滩糙率对应的鱼类栖息地加权可用面积(WUA),分析了糙率的改变对河流鱼类栖息地的影响。结果表明:随着河漫滩糙率的降低,加权可用面积(WUA)逐渐减小,河漫滩范围内WUA的变化幅度比较大,河漫滩的特性对鱼类栖息地面积的影响很大。洪泛区植被的砍伐,会使鱼类栖息地面积减小。因此,应防止洪泛区的过度开发,保护河流生态环境。

SIMULATION FOR THE IMPACT OF FLOODPLAIN WOODLAND DEVELOPMENT TO FISH HABITAT AREA

The development and utilization of the flooding area will inevitably lead to the change of the roughness of the forest in the flooding area. The floodplain is also a part of river flooding area. The decrease of the roughness of the flooding area will increase the flow rate of the river, and then reduce the usable area of the fish. Therefore, in order to provide safe place for fish avoiding risk and to protect the effective habitat area, it is necessary to study the impact of the development of the floodplain on fish.In this paper, River2D software is used to simulate the fish habitat weighted usable area (WUA) corresponding to different floodplain roughness under a certain frequency flood condition, and to analyze the effect of changing roughness on river fish habitat. The results show that with lower floodplain roughness, weighted usable area (WUA) decreases gradually, amplitude of changes about WUA in floodplain range is relatively large, and the characteristics of floodplain significantly affect fish habitat area. The felling of vegetation in flooding area will reduce the area of fish habitat, so it should prevent the excessive development of flood and protect the ecological environment of the river.