Abstract: The unsaturated seepage mechanism in a rock fracture is discussed. It shows that the macroscale(fracture scale) unsaturated seepage can be considered as many microscale(local aperture scale) saturated seepage. Then the critical seepage characteristics are studied by means of renormalization group(RG) theory while the percolation happens. The results show that the critical saturation does exist and there is not any seepage flow.if is less than the critical saturation. Finally, the unsaturated hydraulic conductivity is also discussed.
Abstract: The equations with coupled boundary condition on the interface, which govern the process of pressured pore water infiltration and pore gas flow in unsaturated soils, are established in this paper based on the equilibrium analysis for pore water and pore gas separately. The experiments on the water infiltration in dry sands in one-dimensional channel show the influence of pore gas flowing on the water infiltration process. The numerical solution of the process and comparison of the results between the numerical simulation and the experiment are also proposed.
Abstract: In the karst groundwater exploration study of the Mouthspring Cambrian-Ordovician (∈-O) carbonate aquifer system which is situated on the southwest of Datong of Shanxi Province, environmental sulphur isotopes were used for identifying the origin of karst groundwater, recognizing the environment of karst groundwater with three kinds characterized by its circulation, discharge and recharge, distinguishing the sub-systems of karst groundwater with its mutual relationships. The difference of enrichment of 34 S in species with different valences, the fractionation of sulphur isotopes mainly the isotopic variations of sulphur compounds including δ34S(SO42-) and δ34S(HS-) were used for this purpose. The Mouthspring ∈-O aquifer system is different from two neighbouring ∈-O aquifer systems, the Deityhead and the Threefloor, using the relationships of their sulphur isotopes, δ18O(SO42-) and 14C. Large variations of δ34S(SO42-), δ34S(SO42-) and δ18O(SO42-) were found in karst groundwater, however, the anomalous values were occurred in the Z1 spring of Deithead ∈-O aquifer system.
Abstract: There are some uncertainties in groundwater resources evaluation model, which affect the reliability of groundwater evaluation results. The evaluation results are basic to guide reasonable development of groundwater resource, its reliability is very important in groundwater management. So, a groundwater source field was chosen as a case study. Based on the brief introduction of hydrogeological conditions in the study area, the reliability of groundwater resources evaluation results was quantitatively analyzed.
Abstract: For the study on the behavior of bubbly jets in static environment, it was mainly used the integral model in the past. And there was a little information on the structure of this kind flow. A two-equation turbulence model for two-phase flows is proposed in this paper. In order to understand the law of bubbly jet and give the contrast base between the experimental data and numerical calculation, the experimental data of Sun and Facth is arranged by a set of reference scale found by auther.
Abstract: A two-phase turbulence model and hybrid finite analytic method (HFAM) are used to predict the behavior of bubbly jet in static environment. It has more strong prediction ability than integral method relatively. The agreement between the calculated results and experimental ones show that the turbulence model and HFAM are effective and proper.
Abstract: The situation of water environment and the coordinate degree between water environment and socio-economy in Miyun reservoir area was analyzed.The study shows that the water quantity drifting into the reservoir is decreasing, the water quality in the reservoir is worsening, and there is an acute contradiction between water protection and the sustainable development of socio-economy in the reservoir area. Some suggestions for coordinating the water protection and the sustainable development of socio-economy in Miyun reservoir area were finally presented.
Abstract: Predictive water demand for high, meddle, and low levler during the planning perid 2000-2030 in Taiyuan city are presented. On this basis of the observed hydrological records the sequential generation of preciptation, runoff and groundwater recharge are conducted. By using the developed integral simulation model of water supply system the water supply risk during the planning period is analyzed quantitatively year by year. The operational probability and the expect water price of diverting water from Wuanjiazhe reservoir on Yellow river are estimated.
Abstract: It is planed that the water price which is much lower than Supplying cost now will be rised to cost or meager profit level by 2000. It means the price of irrigation water will rise from 0.03￥/m3 to 0.2￥/m3-0.3￥/m3, that of tap water used for industries will be rised from about 0.5￥/m3-1.5￥/m3 to 3.0￥/m3-4.0￥/m3, and that of tap water used for living will be rised from 0.3￥/m3-1.0￥/m3 to 1.0￥/m3-2.5￥/m3. This strong price rising will decrease violently in the water demand in North China. The total water demand will decrease about 25%-50%, i.e., 132×108m3-250×108m3, which is more than the total amount transferred across Yellow River by the"Medium line" and the "East line" "Water Transfer Projects From Yangtze River to North China".
Abstract: With GIS, the relative maps, the phots, the tables, the documents and the data are integrated into a water resources information system which possesses the ability of friendly interfaces and convenient index. Based on this, the special distribution of the precipitation stations, and the relationship between the precipitation and the terrain in the basin are analysed. Last, the water resources exploring area along the river in Caidam Basin is presented.
Abstract: The DPIV (Digital Particle Image Velocimetry) is a kind of method to obtain velocity fields quickly. But the accuracy of this method is not high. Although the improved methods improve the accuracy greatly, but they lost the advantage of fast processing of DPIV. In this paper, a new method is presented which has the both advantages of fast processing and high accuracy. This new method is based on the DPIV technique which was presented by Willert, and absorts the idea of iteration in Huang's improved method. So the method maintains the advantage of fast processing of DPIV and improves the accuracy to certain extent. It fits for measurements of velocities in constant and tidal flow.
Abstract: Assuming that the population model of flood stochastic process is known, the precison of design flood-control storage calculated by the traditional and the flood simulative method is preliminarily compared. The criterion of the precison evaluation is unbiasness and efficiency of design flood-control storge. In the traditional methods, two design flood hydrgraph enlarging methods are considered, one is same-frequency method, the other is same-multiple method. The Monte-Carlo results shows that the precision of design flood-control storage calculted by the flood simulation method is better than the traditional methods and the same-frequency method is better than the same-multiple method if the form of flood simulation model is correct.
Abstract: Based on Galerkin finite element method, a new upwinding finite element numerical model suitable for modeling wind-driven current in shallow lakes is derived by introducing streamline-upwinding method and the selective lumping coefficient matrix scheme. Moreover it is applied to Taihu Lake, and the morphological characteristic of wind-driven current is discussed.
Abstract: Based on the relationship survied between the level, the area, and the storage of Poyang Lake of 1954, 1957, 1961, 1965, 1967, 1976, and 1984, the shape parameters and its variabilities of Poyang Lake were analyzed, and the variabilties of the yearly maximum level were estimated to reveal the variabilities of water regime. The effects of the innings on the flood levels were researched by using the crossing storage routings of the typical years in order to estabilish the relationship between the effect of the flood level inning effects and the embanked areas reflecting the variabilities of flood innings with the innings. The areas restoring embanked areas to natural state were determined based on the relationship between the benefit of restoring embanked areas to natural state and the states of closing levee levels for large-and middle-size closing levees.
Abstract: The results of serial model tests on hydraulic characteristics and optimal configurations of stilling basin with flaring gate piers (FGP) are presented in this paper. The study reveals that the FGP stilling basin can markedly enhance energy dissipation comparing with the conventional stilling basin. The formuls for calculations of drag coefficients Δζ', hydraulic jump deep tailwater ht, jump length L'j, size of FGP as well as dissipaition rate are also provided.
Abstract: The rainfall characteristics of flood period in Yi-Shu-Si river basin and its possible influence on the river basin is analyzed since the 1950s. The results show that the large flood or the lager flood will occurr when precipitation of the flood period is more than 120% of the normal one.
Abstract: In this article, the principle of precipitation measurement using digital weather radar was introduced briefly, the error in the measuring process and its causing factors were analyzed, and then the methods or steps to reduce the error to lower level were discussed. Finally, having the introduction of operational radar nets in United Kingdom, American, and in the middle stream of Yangtze River, and the experiment project using the Fu Yang digital radar in Anhui Province, the future application of radar in hydrology, especially in precipitation measuring and monitoring, was discussed and prospected.
Abstract: The connotation of crop water use efficiency (WUE) was analysed in detail in this paper. The research history and development of WUE both at home and abroad was reviewed. On the basis of elaborating the concept system of WUE, the calculating models for WUE at different levels were made clear so as to further the study of WUE, which could provide the scientific basis for the high efficiency of agricultural water use and agricultural sustainable development.
Abstract: A survey of Neural Intelligent Information Processing System, based on the combination of neural networks(NN)、fuzzy system(FS) and evolution computing(EC),is introduced. Its application to hydrology and water resources is discussed.