Applied Mechanics and Materials Vols. 353-356

Abstract: In this study, the head loss, turbidity, particle size, and zeta potential were monitored from the effluent of the sand filtration system after backwashing located in Cheng-Ching Lake (CCL) Water Treatment Plant. Moreover, the non-purgeable dissolved organic matter (NPDOC) and excitation emission fluorescent matrix (EEFM) were measured for the collected water samples with or without the pretreatment process. Results indicate that the turbidity of the influent dropped to 0.06 NTU and remained stable after flowing through the sand filter during the 4-hr operation period. However, a continuous increase of the head loss and sand particle size for the sand filter was observed. This phenomenon was opposite with the absolute value of zeta potential. The water samples were collected from the effluent of the sand filter and were treated by a 0.2 μm membrane filter. Thus, higher NPDOC values of sample without pretreatment were observed in comparison with sample with treatment. Results indicate that the sand filter was able to remove NPDOC, and bacteria might proliferate among the sand filter in rapid filtration. Results from the EEFM analyses show that effluents without membrane filtration pretreatment contained a higher percentage of aromatic protein. Compared to the water samples without pretreatment, more humic-like substance was found in the effluent. This reveals that microbial products or bacteria were detached from the fillers after the backwashing process.

Abstract: Drop shafts, especially the vortex drop structure, are vertical conveyance conduits used in hydraulic engineering, water supply and drainage engineering, and so on. Because of complex flow properties and safety requirement, the system running security and reinforcement measure should be verified before it was built. In this paper, numerical and physical simulation methods were employed to verify mutually and analyze the hydraulic characteristics in a tangential vortex dropshaft. It is shown that the water carrying capacity of the dropshaft could be increased suitably and the safety freeboard of the conduit is the limiting factor. The air-water mixing at the junction may reduce the energy dissipation and reinforcement measure for the whole wall is necessary.

Abstract: Based on the understanding of the connotation of water security, firstly the connotation of rural water security is analyzed, and then the relationship between rural water security and new rural construction is discussed. Taking Hebei Province as an example, the main existing problems of rural water security in Hebei province is analyzed from the aspects of rural drinking water security, rural areas irrigation water security, rural drainage water security, finally puts forward some countermeasures for solving the problem of rural water security.

Abstract: Using the analytic hierarchy theory and method to evaluate the related project for optimal selection of water-saving irrigation in the area of Xiaoshan in Zhejiang province. Establish the analysis model of optimal irrigation level and get the total ordering of water saving irrigation mode. Ultimately choose the sprinkling irrigation as the optimal irrigation.

Abstract: Ant colony algorithm, as a new optimized design is introduced in the design of drainage systems. Compared this with manually algorithms on the basis of practical examples, it brightens a promising future in water supply and drainage design.

Abstract: This paper analyzed the water resources and its availability distribution regularities in Northern Shaanxi; and the change laws of water consumption and supply in 1980-2010; according to the relevant planning goal and various industry water standard, forecasted the Northern Shaanxi water demand in future. Result shows that 2020 and 2030 water demand respectively is 1.9×10⁹ m³ and 2.6×10⁹ m³ in Northern Shaanxi. So the 1.6×10⁹ m³ of available water resources at this stage can't meet the future requirements.

Abstract: To resolve the problem that underground pipe network is large, complex, and difficult to manage, the management model based on ArcGIS was used. This paper aimed to transform the traditional data types of underground pipe network to a new type based on ArcGIS and to make statistical analysis and thematic maps output to the attribute datas for all underground pipes mainly including water supply network and drainage network. Through the analysis of pipe network visualization model implementation to build the spatial data model of three-dimensional pipe network, the automatic model from 2D to 3D would be achieved, then the new ways to realize the 3D visualization of urban underground pipe network would be provided. Taking the underground pipe network of a city as an example, the management system based on ArcGIS was built. The system running results show that the system could achieve the digital management of underground pipe network for the city and improve the management efficiency of the entire system.

Abstract: Many cities suffered the frequent waterlogging , the paper analyed current situation of urban drainage,and discussed the problems of urban drainage and then it put forward the measures to improve the urban drainage ability.

Abstract: In study of a series of damages to water distribution systems caused by urban land subsidence, risk assessment modeling is necessary for risk management especially in Mega-cities. First of all, the Catastrophe Theory was employed to analyze the Catastrophe mechanism, and a function catastrophe simulation model was established accordingly to get the vulnerability index of water distribution system. Secondly, risk entropy model was used to analyze the risk of pipe network suffering the land subsidence with the disorder and uncertainty features according to risk theory. Finally, to get the risk index the water distribution system of Guangzhou city was taken to the risk assessment model utilizing the level of land subsidence identified by the dimensional analytical method. The results showed that the risk of land subsidence under the city water distribution system security upgrade is feasible to provide a risk assessment of the strategic decision-making model.

Abstract: Warning lines of surface water, which are important parts of the red line of water resources control and development, have theoretical significance and practical value to comprehensive utilization and scientific management of water resources. Based on the use control line of three red lines, this paper proposed the conception of procedural warning firstly, and gave warning management method of irrigation reservoirs. In the case of the Douyazi Reservoir in Jiaonan, procedural warning lines were given with warning period of non-flood, warning management which supported utilizing water resources reasonably and efficiently with technical basis.