Time filter

Source Type

Zhang W.,Wuhan University | Zhang W.,Security Innovation | Liu P.,Wuhan University | Liu P.,Security Innovation | And 11 more authors.
Water Resources Management | Year: 2015

Operations of multi-reservoir systems are nonlinear and high-dimensional problems, which are difficult to find the optimal or near-optimal solution owing to the heavy computation burden. This study focuses on flood control operation of multi-reservoir systems considering time-lags caused by Muskingum flood routing of river channels. An optimal model is established to jointly minimize the flood peak on the downstream flood control station for the multi-reservoir systems. A hybrid algorithm, Progressive Optimality Algorithm and Successive Approximation (POA-SA), is improved to solve the multi-reservoir operation model by modifying the POA. The POA-SA uses the DPSA to reduce the spatial dimensionality due to the multiple reservoirs, and adopts an improved POA to alleviate the temporal dimensionality caused by the time-lags of the Muskingum flood routing. Linear programming is then implemented to verify the solution of the POA-SA method with a linear approximation of the discharge capacity curve. The multi-reservoir systems of China’s Xijiang River is selected for a case study. Results show that the flood peak of Wuzhou station can be averagely decreased by 6730 m3/s (12.8 %) for the 100-year return period floods, indicating that the proposed method is efficient to operate the multi-reservoir systems and resolve the time-lags issues. © 2015 Springer Science+Business Media Dordrecht Source

Wei S.,Hefei University of Technology | Wei S.,Chongqing Jiaotong University | Zhang Q.,Hefei University of Technology | Liu J.,Hefei University of Technology | And 2 more authors.
Advanced Materials Research | Year: 2012

The general soft soil widely exists in coastal, riverside and lakeside areas. Large area along the Yangtze River in Anhui Province is also the distribution of soft soil. The existence of soft soil has some degree effect on the project construction. According to the laboratory tests, the basic properties of the soft soil in these areas were researched. Based on test results, and compared with the soft soil of other areas, results show that the soft soil of Anhui along the Yangtze River has its own special nature. It include that, compared with other areas soft soil, the soil void ratio and compression coefficient are a little smaller; the consolidation coefficient, permeability coefficient and shear strength parameters are a little bigger; the silt content is above normal. The results and further understanding of soft soil basic nature may have certain guiding significance to construction projects along the Yangtze River region. © (2012) Trans Tech Publications, Switzerland. Source

Qin G.,University of Sichuan | Li H.,University of Sichuan | Zhou Z.,Guangxi Water and Power Design Institute | Song K.,University of Sichuan | Zhang L.,Florida Gulf Coast University
Advances in Meteorology | Year: 2015

Hydrological time series data (1988-2008) of the Hei River, the main water source to Zoige wetland in the Eastern Tibetan Plateau, were investigated. Results showed that the runoff distribution of Hei River varies with the relative change in amplitude (Cm = 15.9) and the absolute change in amplitude (Δ Q = 37.1 m3/s) during the year. There was a significant decreasing trend since 1988 with annual runoff of 20.0 m3/s (1988-1994), 19.0 m3/s (1995-2000), and 15.2 m3/s (2001-2008). There were double peaks in runoff during the water year: the highest peak in the period of 1988-2000 occurred in July while in the period of 2001-2008 it occurred in October. Shifting peak flow means less water quantity in wetland during growing season. Nearest neighbor bootstrapping regressive method was used to predict daily runoff of the Hei River. Model results show that it was fitted with 94.23% of R 2 for daily time series, which can provide a basis for the development and utilization of regional water resources. © 2015 Guanghua Qin et al. Source

Zhang Y.,Wuhan University | Xiao C.,Changjiang Water Resource Protection Institute | Ye M.,Changjiang Water Resource Protection Institute | Tang J.,Guangxi Water and Power Design Institute
Advances in Intelligent and Soft Computing | Year: 2011

This study develops and applies a distributed urban runoff pollution model to the north Moshui lake area of Wuhan for evaluating its non-point source pollution. Based on the research of the urban land utilization and land surface features using GIS, the characteristics of runoff flow, solid suspend (SS) and chemical oxygen demand (COD) on the inlets have been analyzed according the model, the initial pollution loads and the total pollution loads are computed in this study. The results show that the peak of pollutant concentrations are lagged with the peak of rainfall; and the pollutants in initial rainwater are the key part of all pollutants, which often account for 90% proportion. © 2011 Springer-Verlag Berlin Heidelberg. Source

Feng J.-J.,University of Sichuan | Li R.,University of Sichuan | Tang C.-Y.,Guangxi Water and Power Design Institute | Yong X.-D.,University of Sichuan
Shuikexue Jinzhan/Advances in Water Science | Year: 2012

During its transportation over long distances, supersaturated Total Dissolved Gas (TDG) may lead to gas bubble disease or even heightened fish mortality. Because the sediment concentration is always high in spill flow in China, studying the releasing law of supersaturated TDG in sandy water is of great theoretical and practical value. In the experiment described in this paper, we designed three kinds of experimental conditions, including a static water column, stir-induced turbulent water and an open channel flow. For each experimental condition, the TDG release processes were monitored both in fresh water and sandy water. The dissipation coefficients were calculated and compared under different sedimentation levels. The results indicate that both sediment and turbulence intensity can increase the release speed of TDG. The higher the sediment concentration level and turbulence intensity are, the greater the dissipation coefficients are. This study can provide important guidance for determining dissipation coefficients in a TDG simulation model, and can serve as a reference in exploring mitigation measures of supersaturated TDG. Source

Discover hidden collaborations