Study Of Eco-environmental Water Requirements In The Yellow River Delta

In recent years, along with the human developing in society and economy, the water resources excess exploitation and use as well as the pollution produced by humanity dumped pollutants had brought a series of eco-environment questions such as the river course to block the flow, the wetland shrinking, deterioration of the water quality, the soil erosion seriously, the biodiversity reduction and so on. How to solve such problems, the regional eco-system to give appropriate water demand and ensure the healthy development of eco-systems have been become an important issue. Therefore, this paper took the Yellow River delta as an example, it has conducted the research to the region eco-environment water demand, and established the Yellow River delta eco-environment water demand model, finally calculated the different levels of ecological water demand that maintains the ecological balance of the required. The main contents of this study are shown as follows:1. Summarized the existing eco-environmental water requirements and presented the concept system and connotation that suits the eco-environmental water requirements of the estuary region. The eco-environment water requirements is not a fixed value, but always changes in a reasonable threshold value sector, therefore it is divided into three different ranks that are the minimum eco-environmental water requirements, and suitable for eco-environmental water requirements and the maximum eco- environmental water requirements respectively.2 Based on the analysis of eco-environmental water requirements characteristic foundation, the ecological environment water demand frame and the step was proposed, and the Yellow River delta eco-environmental water requirements model is constructed. This model contains three parts that are the rivers eco-environmental water demand, the wetland eco-environmental water requirements and the estuary eco-environmental water requirements. 3 Separately calculated the water requirement of the individual, and in accordance with the principles of the leading priorities functions Yellow River delta smallest ecological environment water requirements for 88.4×108m3, being suitable ecological environment water requirements for 187.41×108m3,largest ecological environment water requirements for 393.08×108m3.4 Analyzed the relations between the ecological environment requirements and the current ecology water used present situation, the ecology water of the Yellow River delta could merely satisfy the smallest ecological environment water demand, And at suitable ecological water requirement of water and maximum standards are shown under the water shortage situation. The proportion of different function ecological environment water demand is analyzed; the vegetation and sediment water requirement are a larger proportion in this total requirement. But the river course evaporation, the leakage water demand and the wild biological habitat water demand accounts for the total quantity proportion relatively small. The estuary eco-environmental water demand function is mainly reflected in the functional balance of sediment erosion and deposition. Therefore, adopts the effective current of water to flush the silt measure or to enhance fluent alluvium ability, will effectively reduce the Yellow River delta ecology water demand.Based on above studies, the Yellow River delta eco-environmental water demand computation model has been established, and calculated water demand under the different rank, this research results can be used to regulate the water resource of the estuary and downstream reach of the Yellow River.