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Zhang H.,Changan University | Wang Y.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Jiang X.,Yellow River Institute of Hydraulic Research
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2011

The difficulty in quantifying the ecological target is a general scheduling problem in the field of reservoir ecological regulation, and the micro-ecological requirements for the macro-control of river are often hard to satisfy. In the paper, a flow restoration method is adopted to obtain the flow process that is needed for the restoration of river eco-hydrological system health, and by this method a model is developed for the integrated scheduling of cascade reservoirs on the Yellow River mainstream. Through controlling the flows at the Yellow River eco-sections, water allocation schemes under different ecological requirements in the present conditions are obtained by applying this model. The calculations show that the eco-flow control greatly increases the design probability of water supply in the lower reaches of Yellow River, while causing small changes in water stress index, power generation and ecological damage rate. In the future 2020, however, the eco-flow control only brings about some increases in water stress index and ecological damage rate, but nearly no improvement on water supply or power generation. Thus, we conclude that the indicators' responses to reservoir ecological regulation in the Yellow River basin was not significant at present, while after 2020 the regulation will play an important role in the ecological protection to this basin and nearly no role in the power generation of cascade reservoirs. In the future, ecological regulation may become a crucial technique in relieving the pressure of increasing ecological damage rate and a possible measure for protecting the ecosystems. To meet the ecological water demand along the Yellow River mainstream, however, greater difficulties remain, unless drawing water resources from other river basins. © Copyright. Source


Wu H.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Huang Q.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Xi S.,Sun Yat Sen University
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015

This paper applies a variable fuzzy set method based on entropy weight to construction of a framework of classified real-time flood forecasting using the concepts of clustering and classification. Fuzzy clustering was used to classify historical floods based on the flood antecedent impact factors and time-varying rainfall information. In the present study, this conceptual hydrological model was calibrated for each type of flood. In application, a fuzzy diagnosis model was used to identify the types of floods in future by using the flood information obtained. Results show that the classified framework gives a fast and accurate diagnosis of the type of flood and significantly improves the accuracy of flood forecasting. © Copyright. Source


Chen T.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Chen T.,Shanxi Company of Real Estate Service | Xie J.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Zhang G.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | He W.,China Communications Construction Company Ltd.
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2012

This paper purposes a dynamic parameter estimation method of Muskingum routing model for real-time flood forecasting based on BP artificial neural network to overcome the low accuracy problem of averaging and grading method in parameter calibration. In this new method, first flood characteristics are analyzed to obtain BP inputs and then an optimization algorithm is used for calibration of model parameters, i.e. BP outputs that are used for neutral network training. Application of this calibrated BP model to real-time flood forecast shows that the model is simple and more accurate. © right. Source


Zhang X.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Zhang X.,Shaanxi Provincial Academy of Environmental Science | Yu G.Q.,Key Laboratory for Geo hazards in Loess Area of Ministry of Land and Resources | Li Z.B.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | And 2 more authors.
Water Resources Management | Year: 2014

The relationships between precipitation, vegetation and erosion are important yet unresolved issues in the field of earth surface processes. Vegetation plays an important role in controlling soil erosion. Through field simulated rainfall experiments, we analyzed the characteristics, regulation of, and correlation among the slope rainfall-infiltration-runoff, erosion and sediment under different vegetation types. The results showed that the forest effectively improved soil structure, had stronger runoff and sediment regulation and was influenced less by rainfall intensity than those under other vegetative conditions. In addition, the efficiency and pattern of the regulation of runoff and sediment varied with vegetation types as did the mechanism of action. The soil and water conservation function of forest was water storage and sediment reduction by plant root systems to reduce erosion power, increase infiltration, decrease runoff and reduce flow speed. The function of grassland was direct sediment interception based on surface vegetation canopy for runoff and sediment regulation. The root contribution to runoff and sediment reduction was relatively greater than the shoot contribution under forest conditions, whereas, the effect of shoots and roots on soil loss was almost equivalent under grassland conditions. The different spatial structures of vegetation affected runoff and sediment regulation in different ways, and plant root systems were crucial for soil and water conservation. The cumulative sediment yield of the slopes increased as a statistically significant power function of cumulative runoff. The coefficient and curve shape of function were dependent on vegetation type, soil properties, rainfall intensity and surface roughness. The process of slope runoff and sediment was divided into development, active and stable stages. These stages correlated with each other to constitute a complete rainfall-runoff and erosion-sediment process, which exhibited their own features at each stage. This study furthers understanding of the relationships between vegetation, soil erosion and precipitation. © 2014 Springer Science+Business Media Dordrecht. Source


Wan F.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Yuan W.,Zhengzhou University | Huang Q.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT | Chang J.,Key Laboratory of Northwest Water Resources and Environment Ecology of MOE at XAUT
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2010

Optimal operation of a complex cascade reservoirs system, mathematically high dimensional, often encounters dimension disaster and is trapped into a local optimum. This paper suggests a method of particle swarm optimization that is solved by the immune evolutionary algorithm. The algorithm combines the abilities of global searching of immune evolution with local searching of particle swarm, and hence avoids dependence on initial population and local trapping. A test case shows this new algorithm superior to progressive optimization. Source

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