| Zoning of Chinese flood hazard risk |
| ZHANG Xingnan1,LUO Jian1,CHEN Lei1,LI Hong1 |
| (1.Hohai University,Nanjing 210098, China) |
Abstract:The definition of flood hazard includes two aspects:flood and hazard.In this paper,the flood risk is zoned by means of reason analysis in consideration of meteorology,runoff and topography.The distributions of tillable field and population are used as the economics index to zone the hazard risk caused by flood.The zoning maps of flood and flood hazard have been ratified by experts and provide the basis for macroscopic decision making in the planning of flood control.
Key words:flood;hazard;risk;zoning.
| A novel expert system for identifying unit hydrographs and its application |
| SHU Chang1,JIANG Tiebing1,LIANG Chaoying2 |
| (1.Huazhong University of Science and Technology,Wuhan 430074,China;2.Zhexi Water Power Station,Hunan,China) |
Abstract:According to the features of rainfall distribution varying with time and space,a novel expert system(ES) for idnetifying the unit hydrographs automatically varying with time is proposed in this paper to solve the problems arising from the simplification of unit hydrographs method.The relationships between the characteristics of rainfall and unit hydrographs in a river basin are studied and a real ES is established by using the advanced softwave system PowerBuilder.The application of the proposed method to the flood control decision support system(FCDSS) for Zishui river basin is presented.It is concludedthat the precision of flood forecasting is better than that of the conventional methods.
Key words:unit hydrograph;expert system;PowerBuilder;identification
| On the theromo characteristics of the rain zone of counter flow cooling tower |
| ZHAO Zhengguo1, SHI Jinling1, ZHOU Changhong1,TENG Xinjun1 |
| (1.China Institute of Water Resources and Hydropower Research, Beijing 100044) |
Abstract:Based on the data from heat water experiments for counter-flow and cross flow cooling tower in laboratory with different water flow rate,air flow rate and water falling height, the equivalent diameters of water drop under corresponding conditions are obtained. According to these water drop diameters and heat conduction formula, the thermo characteristics of rain zone in industrial cooling towers can be computed and illustrated by figures and formulas. Thus,the temperature differences in rain zone of cooling tower can be calculated.
Key words:cooling tower; counter flow;rain zone;thermo characteristics.
| Multi-objective oriented river embankment management information system |
| TAN Xuming1, MA Jianmin, LU Juan1 |
| (1.China Institute of Water Resources and Hydropower Research, Beijing 100044,China) |
Abstract£ºThe river embankment management information system for Jinma river section of Min river is established, based on the platform of Mapinfo of GIS system. Multi-objective is the guideline of the design and development of this system. The specialty of river dykes and the requirements for management are fully considered.
Key words£ºriver dykes; informatioon management system; GIS; mapinfo;multi-objective.
| Study on some characteristics of evaporation of sand dune and evapotranspiration of grassland in Mu Us desert |
| LI Pingfang1, LI Baoguo1 |
| (1.China Agricultural University, Beijing 100094,China) |
Abstract:The formation of dry surface layer and its effect on characteristics of evaporation of sand dune and the evapotranspiration of grassland in the Mu Us desert are discussed in this paper. The result shows that the amount of evaporation from sand dune is dependent on the thickness of dry surface layer and soil temperature and could be calculated with a model of dry surface layer.The measurement indicates that evapotranspiration of grassland is significantly greater than that of sand dune and the average evapotranspiration of grassland is 5mm/d (summer) in the Mu Us dessert.
Key words:Mu Us desert;dry surface layer;evaporation; evapotranspiration
| A new large weighing lysimeter and its application to agro-hydrological process studies |
| LIU Shiping1, YANG Jianfeng1, LI Baoqing1, LI Yunsheng1 |
| (1.Institute of Geography,CAS,Beijing 100101) |
Abstract:A large weighing lysimeter is installed at Yucheng Comprehensive Experimental Station for agro-hydrological studies.Features of the lysimeter include the following:1.Mass resolution equivalent to 0.016mm of water to accurately determine hourly evapotranspiration,groundwater evaporation and groundwater recharge simultaneously;2.A surface area of 3.14m2 and a soil profile depth of 5.0m to permit normal plant development,soil water extraction,soil water/groundwater exchanges and fluctuations of groundwater level;3.A special supply-drainage system to simulate field conditions of groundwater within the lysimeter,4.A soil mass of about 30Mg including both unsaturated and saturated loam.The soil mainly consists of mealy sand and light loam.The monitoring data indicate that during the growing period of winter wheat groundwater contributes16.6% of total evapotranspiration for water-table depth from 1.6m to 2.4m below ground surface.Excess irrigation reduces the amount of upward water flow from groundwater table and causes deep percolation to groundwater.
Key words:GSPAC system; weighing lysimeter; evapotranpiration; water exchanges; soil water; groundwater.
| Computational analysis of water hammer prevention devices for solid-liquid two-phase flow pipelines |
| HAN Wenliang, WANG Guangqian, HAN Jun |
(Tsinghua University,Beijing 100084) |
Abstract:According to the characteristics of solid-liquid two-phase flow,the equation of motion and the equation of continuity for hammer computation are deduced in this paper.The equations are applied to analyze the effect of different prevention deveces used to relieve water hammer pressure in pipeline transport with displacement pumps.It is concluded that the air vessel and pressure relief valve are better than other devices.
Key words:equation of motion; equation of continuity; air vessel; pressure relief valve.
| Visualization of flow structure around submerged spur dikes |
| PENG Jing1, Yoshihisa Kawahara2 |
| (1.China Institute of Water Resources and Hydropower Research,Beijing 100038;2.Public works Research Institute,Japan) |
Abstract:The dye injection and oil-film method together with electromagnetic velocimeter are applied to measure the flow field around spur dikes.The observed information shows that the flow is three dimensional and unsteady due to the fluctuating circulation zone and surface wave.The dye injection clearly visualizes the flow pattern of instantaneous 3-D flow while the photos of oil film well demonstrate the scale and location of the eddies.The flow characteristics that obtained by using flow visualization technology are highly consistent with the velocity distribution measured by electromagnetic velocimeter.
Key words:spur dike; turbulent flow; flow visualization.
| Action of fluid on aqueduct body during strong earthquake |
| LI Yuchun1, LOU Menglin1 |
| (1.State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University,Shanghai 200092,China) |
Abstract:The boundary element method is applied to simulate nonlinear sloshing of fluid,dynamic horizontal force and overturning moment actingon the aqueduct body during earthquake.The computational results of BEM(nonlinear)are compared with that of linearized theories.The numerical results reveal that a great horizontal force acting on the aqueduct body may occurred during strong earthquake.This action must be considered in seismic resistance design.
Key words:strong earthquake; fluid action; nonlinear slosh;aqueduct; boundary element method.
| Evaluation and calculation of irrigation quality in surge flow irrigation |
| WANG Wenyan1, WANG Zhirong1, FEI Liangjun1, WANG Quanjiu1, Zhang Jianfeng1 |
| (1.Xian University of Technology, Xian 710048) |
Abstract:Based on the field experimental data both for clean and muddy water under continuous irrigation and surge flow irrigation, the water uniformity, irrigation efficiency and water storage efficiency of surge flow irrigation are firstly evaluated in this paper. A new method for calculating the criteria of surge flow irrigation quality is suggested. This method enables the evaluation to be carried out without soil water data after irrigation, thus makingit possible to simulate the irrigation quality mathematically and optimize the irrigation technical element in surge flow irrigation.
Key words:muddy water; surge flow; irrigation water uniformity; irrigation efficiency; water storage efficiency.
| Research on submerged vanes for bank protection in river bend |
| WANG Wenye1,WANG Zhenduo1,YANG Jinliang1,ZHANG Xiaohui1 |
| (1.Jilin Water Resources research Institute, Changchun 130022,China) |
Abstract:This paper analyzes the essential features of bend flow, describes the relationship between submerged vanes characteristics and induced bed shear stresses, give the theory and design procedure of bank protection of river bend by using submerged wanes. The reasonability of the theory is verified by field tests.
Key words:features of bend flow; submerged vanes; bank protection;field tests.
| Amonochromatic wave transformation model taking into account the dispersion of phase velocity |
| LI Ruijie |
| (Ocean University of Qingdao, Qingdao 266003) |
Abstract:A new explicit formula is presented do approximate the nonlinear dispersion expression suggested by Hedges(1987), in which the phase dispersion effect is taking into account. The present explicit formula is in good agreement with the original empirical formula. Combining this formula with the mild slope equation, a monochromatic wave transformation model taking into account the dispersion of phase velocity is developed. The model is tested against the laboratory data. It is shown that the suggested mathematical model is in good agreement with experimental data.
Key words:dispersion of phase velocity; explicit non-linear dispersion relation; monochromatic wave; mild slope equation.
| Analysis of flow pattern in outlet conduit of pumping station |
| LU Linguang1,LIU Lijun1,LIU Jun1 |
| (1.Yangzhou University, Yangzhou 225009; 2.Jiangsu Consultin Centerof Water Conservancy Engineering, Nanjing 210000) |
Abstract:In order to improve the hydraulic design of outlet conduit, the basic flow patterns in outlet conduits including siphon, straight tube and inclined conduit are simulated by numerical computation of 3-D turbulent.It is found that the diffusion in horizontal direction is better than that along the vertical direction, since vortex is existed. The vortex influences the velocity distribution at the section. It is suggested that the diffusion in the horizontal direction of the conduit should be utilized to restrain the effect of the vortex.
Key words:pumping station; outlet conduit; flow pattern, analysis.
| Risk analysis of groundwater allowable withdrawal evaluation |
| SHU Longcang1,ZHU Yuansheng1,SUN Qingyi2,PENG Xuming2 |
| (1.Hydrology,Water Resources and Environmental Engineering College, Hohai Univ., Nanjing, 210098, China£»2.Water resources Bureau of Jining City, Jining, 272119,China) |
Abstract:Traditional evaluation method of groundwater allowable withdrawal is based on determination model. But, there are some uncertainties in groundwater allowable withdrawal evaluation, and ¡°risk¡± is closely related with ¡°uncertainties¡±¡£The evaluation of groundwater resources in Jining City, Shandong Province is chosen as case study. Based on the introduction of the concept of risk analysis and the methods for analyzing risk, risk analysis of groundwater allowable withdrawal evaluation results was carried out for Jining City. The results obtained from risk analysis accord closer with the practical situtation then traditional methods results. The study results indicate that risk analysis is a more practical, reasonable and reliable evaluation method of groundwater allowable withdrawal, which can minimize the loss with the groundwater pumping decisions.
Key words:groundwater; allowable withdrawal; uncertainties; Monte-Carlo; sensitivity analysis; risk analysis