Huai W.,Wuhan University |
Chen G.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Zeng Y.,Wuhan University
Journal of Hydroinformatics | Year: 2013
The apparent shear stress acting on the vertical interface between main channel and floodplain (with and without vegetation) in prismatic compound open channels was studied using artificial neural networks (ANNs). Apparent shear stress is commonly used to quantify the transverse momentum exchange between sub-areas of the cross section, and its influencing factors include channel geometry, boundary roughness conditions and hydraulic properties of flow. In particular, if vegetations exist, the eco-characteristics of vegetation can be crucial. To mathematically describe the effect of channel symmetry, we present a new expression of width ratio through which the symmetrical and asymmetrical cross section can be distinguished. The effect of vegetation is considered using degree of submersion and the porosity (volume ratio occupied by water). Dimensional analysis was conducted to determine the mathematical formula of apparent shear stress, and seven non-dimensional parameters were selected as the influencing factors. In total, 260 sets of data (including our new experimental series conducted in a compound channel with vegetated floodplain) were used for training and testing a three-layer, feed-forward neural network with Levenberg-Marquardt (LM) as the selected training algorithm. Also, the effects of main influencing factors on the apparent shear stress were investigated. © IWA Publishing 2013.
Ma W.,China Institute of Water Resources and Hydropower Research |
Pu C.-S.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Luo J.-C.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Chen X.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2013
Based on flow characteristics of medium and large-sized shallow lakes at home and abroad, the flow characteristics of outer lakes of the Dianchi Lake such as wind-driven current, wind surge flow, circumfluence, eddy current and flow in plants were analyzed and summarized. Wind is a major driving force of flow movement in the Dianchi Lake, the water amount filing into and discharging from the lake has relatively small impact on the flow pattern in it; accordingly the mixed circulation patterns are formed with wind-driven flow as main body and throughput flow as supplement. Integrated the wind flow characteristics with circulation features and differences in spatial distribution of hydrodynamic condition of outer lakes of the Dianchi Lake, the material basis, power source and formation mechanism of blue-green algae accumulation are put forward in the north bank of the lake, and some countermeasures and suggestions are proposed on slowing down the blue-green algae accumulation on the north bank in outer lakes of the Dianchi Lake and improving the water quality on the retention zone.
Ma P.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Lei Y.,Yunnan Agricultural University |
Mao C.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Gu S.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Yang S.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute
Advances in Science and Technology of Water Resources | Year: 2015
This paper analyzes the total water control targets in states (cites) in order to implement the general requirements of the most stringent water management system. Based on the current situation of water supply pattern in Yunnan Province, combined with the water project construction planning, a model for water resource system simulation is developed with water resources configuration management tool MIKE BASIN. Additionally, it is also presented the water allocation among various sectors and states (cites), and water-supply pattern among the various water projects in 2020 and 2030. To 2030 target year, through promoting construction of water-saving society, water projects, Water Diversion of the Central Yunnan and other projects, ecological and socio-economic water demand will be satisfied, in line with total water control and water efficiency control constraints. ©, 2015, Editorial Office of Journal of Hohai University (Nature Sciences). All right reserved.
Chen J.,Yunnan Water Conservancy and Hydroelectric Survey Design and Research Institute |
Wang W.,University of Sichuan
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015
Copula function is used to combine the correlation degree and relevance pattern of independent variable and dependent variable. A joint distribution function can be constructed, and its interrelated structure with the two variables is analysed. Then, expressions for the relation of the marginal distribution of dependent variable versus the joint distribution are formulated, and the unknown value of dependent variable is predicted through a combination with the known sample value of probability distribution of independent variable. Case study of annual runoff prediction shows that this Copula prediction method has a clear theoretical basis and it is stable and accurate. This method not just provides new ideas for hydrological prediction, but offers new insights into Copula function. ©, 2015, Tsinghua University Press. All right reserved.