Abstract:
In order to analyze the effectiveness of combined measures of habitat reverse reforming and ecological operation to controlling the Elodea canadensis disaster in the Wangfuzhou Reservoir area on Hanjiang River, this paper established a two-dimensional hydrodynamic model of the study interval based on the actual measurement, and proposed the concept of hydrodynamic improvement rate.We quantitatively analyzed the effect of habitat reforming in terms of typical section and flow field, and discussed the ecological flow and regulation scheme after habitat reforming.The results show that:(1)After the habitat reforming, the overall water depth of the characteristic points at cross-sections increased by 1.31 m, the flow velocity distribution was more uniform, and the numbers of still water points were significantly reduced.(2)The largest hydrodynamic improvement rate of the research interval after reforming was in dry water flow(44.55%),and the smallest was in flood flow(26.77%),and the periodic improvement rate was 35.59%.(3)The peak ecological flow after the habitat reforming could be reduced to 613.72 m3/s, which had an equivalent hydrodynamic improvement effect with the existing dispatching scheme of 1100 m3/s of short-term water discharge.Based on this, one time ecological dispatching can save 420 million m3 water volume of Danjiangkou Reservoir compared with the existing dispatching scheme, and the hydrodynamic improvement rate could reach17.2% under the same minimum flow rate.