Advanced Materials Research Vols. 518-523

Abstract: Composite roughness is an important parameter in river hydraulic calculations. In this paper, various typical methods for predicting composite roughness of river were summarized, including Einstein Method, Lotter Method, JIANG Method and Weighted Average Method, their theoretical rigors were discussed from both perspectives of minimum energy dissipation principle and analytical analysis, and their calculation precisions were verified by a large number of flume test data. Research shows that Einstein Method complies with the principle of minimum energy dissipation, also is the necessary and sufficient condition of resistance equation having unique solution, and its calculation precision is higher, therefore, Einstein Method is more suitable for composite resistance calculation of river with single cross section.

Abstract: It is an important means of hydrological data analysis for drawing hydrological data curve. The paper conducts a study on drawing method of stage-discharge curve in two aspects including BP neural network approximation and curve fitting, according to data extracted from a hydrologic station located in Suqian section of Beijing-Hangzhou Canal. Normalization of the input sample is processed in order to caculate conveniently and prevent partial neurons to supersaturate. Then, neuronal number is determined by method of heuristics. And the transfer function and training function are finalized on the premise of target error 0.0001.Error analysis is performed after simulation of BP network approximation. 2- and 3-order curve fitting is done based on principle of least squares of polynomial fitting, then followed by error analysis. Comparison of both methods comes to the conclusion that approximation of BP network for a given data is more accurate than that of curve fitting.

Abstract: There is a close relationship between surface water and groundwater in semi-arid and arid areas of China, and thus researching on the interactions of them is of importance for reasonable water resources development. This paper took Bulang River basin as case study, analysis and discussion were conducted to water chemistry and isotopes tests results of water samples. The results show that surface water in Bulang River basin mainly relies on precipitation recharge, partially on groundwater recharge, the hydrochemistry type of surface water is mainly Ca-HCO₃ with low salinity.

Abstract: Source of water is the beginning of rural drinking water projects, safe water source is the key to rural drinking water safety. Status of rural drinking water source in china and laws and regulations on rural water conservation were analyzed. The population of centralized water supply accounts for 51% of the total population in rural areas in 2008, centralized water supply 49%. Groundwater source accounts for 57% of the population of centralized water supply projects in rural areas in 2008, surface water sources 43%. China has a relatively sound legal system of drinking water source, including basic law, general law, administrative regulations, local regulations.The paper draws a conclusion that sources of drinking water in rural areas is mainly groundwater, water conservation is short of specific laws and regulations and not suitable for rural area,it is necessary to improve laws and regulations on rural water conservation, government must assume responsibility for rural water conservation, especially financial investment and public policy support.

Abstract: In order to guide geothermal well reinjecting in the geothermal aquifers.4 different reinjected modes were adopted, analyzed the capacity and lasted time, the water level moved and the absorbing water index changed in accumulative reinjecting. Test results show that under the condition of the intermittent nature, Lasted time is short, reinjecting capacity is limited, in "wash well-reinjecting" mode, the volume of reinjected water is increased with the time of washing well, lasted time is longer, the volume of reinjected is greater, the volume decreased gradually in pressurized reinjected mode, the capacity of system has a great effect on operating the way. The research results have theoretical and practical significances for geothermal reinjecting well in porous aquifer.

Abstract: A fuzzy matter-element evaluation modeling based on cooperative game weight (FME-CGW) is presented in this paper. Based on cooperative game theory, authors introduce a cooperative game weight which embodying an idea of competition and coordination among different weight methods. Based on the cooperative game weight, employing fuzzy matter-element theory and Hamming approach degree, the authors develop FME-CGW model. The derived model is applied to assess the groundwater resources carrying capacity in Guanzhong plain in Shaanxi province. The results are reasonable and satisfactory by comparing to other methods. The study of this practical example shows that the modeling presented in this paper is a new method with simple algorithm and strong practicability, which can be adopted to analysis various comprehensive evaluation issues.

Abstract: This paper aims to study the use of higher probability moments (PWMs) for flood frequency analysis. By estimating the parameters of GEV distribution and matching higher PWMs to annual maximum flow series in northern Shaanxi. The results show that higher PWMs describe the data reasonably better than lower PWMs in flood analysis. This method involves no more complication than lower PWMs that be commonly used, and is suitable for flood frequency analysis.

Abstract: In order to tackle the existing problems of silt-removing, a new stir-scour dredging technology, especially applied in the Yellow River irrigation areas, is introduced in the paper. Furthermore, numerical simulation and hydromechanics is respectively utilized to study the mixing and settling process of river sediment and to analyze flow characteristics, silt-removing process in the design condition, which shows that the new stir-scour dredging technology is ideal and easy practice especially for the Yellow River.

Abstract: In order to study the vary circumstance of underground water level of multi-level groundwater. This paper takes example for the Shenyang Eco-Tech Development Zone of Liaoning Province .Firstly, a conceptual model is built in this paper. Secondly, the groundwater system is numerically simulated and forecast with the internationally standard Visual Modflow. According the results of numerical simulation ，It is proved that between the underground water level’s calculating result and observation result has a higher fitting degree, and the results testify that the mathematical model established in this paper is reasonable. Conclusion the validated mathematical model can be used to simulation and forecast of the underground water level in the research area.

Abstract: Precipitation and seawater level are the two important factors to be considered in seawater intrusion simulation. However, these data are lacking in some regions of the world. Thus, limits the study on seawater intrusion. Considering the lack of availability of data on precipitation and seawater level, an atmosphere–ocean-groundwater modeling system was constructed in this paper. In the modeling system, the atmosphere model (MM5) and the ocean model (POM) is used to simulate the precipitation and seawater level, respectively while the SEAWAT model is used for groundwater model simulation. The system is used for seawater intrusion simulation case study in the Liaodong Bay coastal plain. The study shows that the atmosphere–ocean-groundwater modeling system provides a very reasonable result.