Dahuangpu Depression Detention Basin Flood Control, Flood Resources, Economic Development And Ecological Repair And Reasonable Mode To Explore

In the past decades, sustainable development in detention areas has been ignored except some measures in safety constructions. Because of unsuitable development and redoubled population, utilization of detention areas falls into a dilemma. In case of flood detention, it will cause great damages and increase government's burden in relief and compensation; inversely, the key protected areas will be in danger. Thus, sustainable economic development pattern should be studied for the detention areas, by which the relative damage could be smaller and economy could be prone to recovery after flooding. Meanwhile, the development in detention areas should be coherent to the eco-environment instead of degradation in surroundings. In the semi-humid North China, detention areas can also be used to shift flood as water resources. The Dahuangpuwa detention area in Haihe river basin was selected as an objective for investigation, in which flood defence, floodwater utilization, economic development and environment protection issues are considered comprehensively.Dahuangpuwa detention area is an ideal water storage and wetlands recovery place because of its less infiltration. Due to the uncertainty of flood and especially severe water shortage in Haihe River basin, if only relying on river flow, it is difficult to guarantee the water resources for the economic development and wetlands rehabilitation. The Beijing Sewage Canal along the west of the detention area is actually one steady water resource, but the situation that the polluted water being used directly should be transformed.Taking the observed discharge curve of the 1975' flood and 1984'flood as typical case, the flood characters before and after reservoir construction in Dahuangpuwa detention area have been analyzed by a flood simulation model. The result shows that the flood defense standard will be improved from 5-year to 50-yearafter reservoir construction. Furthermore; about 10 million m3 floodwater can be used as water resources annually in average. Based on the flood simulation model; the introduced water quality assessment model and flood damage assessment model can be used to analyze the interactive water quality relationship between flood and reservoir; as well as the flood damage of detention area.Three scenarios are designed in this dissertation: continuing traditional pattern; utilizing floodwater as resource and taking sustainable development mode. By comparison with three scenarios in terms of flood protection; flood resource usage; economy development and environment protection aspects; the sustainable development scenario is proved to be the optimum scenario. In this case; the flood damage in detention area will be relatively lower; some natural and man-made wetlands can be rehabilitated by using floodwater and polluted water from the Beijing Sewage Canal; and then the primary retreated water can be used for agriculture irrigation and fish cultivation; the environment will be protected in a sustainable way; and the people living in this area will also be greatly improved by developing the proper industries based on the reservoir. In this study it is concluded that the sustainable development scenario; which synthetically considering flood defence; flood resource utilization and environment protection aspects; presents an ideal development mode for nature and human coherence development in the Dahuangpuwa detention area.