Advanced Materials Research Vols. 1073-1076

Abstract: Rainfall is one of the main factors that drive soil erosion, leading to environmental problems such as increased frequency and severity of debris flows, and ecosystem damage. Rainfall erosivity represents the potential of rainfall to cause soil erosion, and is determined by a combination of rainfall intensity. The spatial and temporal distribution of rainfall erosivity was analyzed to get its relationship with the debris flows in the Bailong River Basin in China's Gansu Province. The mean annual amount of erosive rainfall accounts for 36.0-47.1% of annual precipitation. The annual mean rainfall erosivity amounts to 798.8 MJ mm ha^-1 h^-1 yr^-1 in the Bailong River Basin. A positive correlation between annual precipitation and annual rainfall erosivity was demonstrated at all 18 rainfall stations. However, further research is required to reveal the key factors that explain soil erosion and debris flows.

Abstract: In order to explore the effects of water-nitrogen coupling on dry matter and nutrient accumulation of flue-cured tobacco, 9 treatments with different lowest limits and nitrogen fertilizer amount were designed, and the distribution and accumulation of dry matter and nutrient (N, P and K) of flue-cured tobaccos under water-nitrogen coupling treatments were observed. Results showed that: (1) High irrigation amount could not certainly increase the dry matter accumulation of tobacco root, but which was beneficial to the dry matter accumulation of whole tobacco plant. (2) Dry weight proportion of flue-cured tobacco leaves was highest, which was above 55% among the treatments. (3) Higher water and nitrogen promoted the nutrient accumulation of flue-cured tobaccos, nutrient content of W3N3, W3N2 and W2N2 was higher compared to other treatments.

Abstract: In order to study the features of Mountainous watershed runoff and erosion in karst region, , on the basis of design of experiment of the the big pore, slope runoff and erosion, artificial rainfall runoff experiment is made, by establishing artificial rainfall, slope runoff test plot. Large quantities of data were obtained through the artificial rainfall test. According to the experimental data, under different rainfall intensity, rainfall, under the pad surface and rainfall process, regularity of slope runoff and sediment yield in karst area is studied to provide data validation for the development of slope runoff and sediment yield model in karst region.

Abstract: For many hydrologic analyses, planning or design problems, reliable rainfall estimates are necessary. For this reason, an accurate estimation of storm event properties is central to continuous simulation of rainfall. Rainfall is generally noted as single events or storms where the beginning and the end are defined by rainless of particular size duration called Minimum Inter-event Time (MIT). Starting from a critical study of the state of the art, this paper intends to investigate the definition of MIT for rainfall events shorter than an hour that, on an urban scale, are the most critical for designers, planners and operators of urban drainage system. All event characteristics such as depth and mean rain rate, are influenced by the choice of the value of MIT. This paper reviews the range of approaches used in literature and after this, based on a year of pluviograph records on an urban catchment, proposes a value of MIT according to catchment network entry time.

Abstract: In the region where Eastern Ningxia coalfield locates, with the fragile eco-environment and the relative short water resources, it is significant to make clear the influence of coal mining on the groundwater in this region. According to analyses of water-filling factors for the 21 mine fields in the 7 mining areas and 1 independent mine field of Eastern Ningxia coalfield. Firstly, this paper selects the formula in the regulations on the preserving of the coal pillar and coal mining under buildings, water, rail and main shafts (regulations for short) and the Standard on the Exploration of Hydrogeology and Engineering-Geology in the Mining Area (GB12719-91) (standard for short) to calculate the height of water-flow fractured zone in the first coal seam mining, and compares the analysis results of the above formula to the observation data of 3 working faces, and determine the estimated method on the height of water-flow fractured zone, and then use “three maps-two predictions” method to complete the criterion of aquifer water-enrichment and inbreak in safety of the first coal seam. Finally, analyzing the influence of coal mining on the direction of groundwater and recharge-runoff-discharge conditions, the final comprehensive division program on the risk of the groundwater inrush is presented. The research results served as the general guidelines for the mine operations.

Abstract: Based on the cascade reservoirs of Li Xianjiang basin, the study of cascade energy storage operation chart was carried out in this paper. Combining the commonly used discriminant method in joint dispatching of cascade reservoirs, the drawing method of energy storage scheduling figure was described detailedly, especially the calculation process of deriving the typical runoff that corresponds to the up and down basic scheduling lines. Considering the power generation reliability was enhanced when implementing the joint operation for cascade reservoirs, the maximum power generation model based on energy storage operation chart was proposed in this paper, and the progressive search method is used in the solving process of the model in a certain range of guaranteed output. In addition, result of the model was further optimized by using Progressive Optimal Algorithm, and comparing the optimized result with the conventional dispatching scheme under the unchanged guaranteed output, the power generation has increased 0.04 million kWh and assurance rate increased 9%.

Abstract: Shaizhudong spring is the largest karst spring in the central of north of the Weihe River, Shaanxi Province, China. A lot of studies have been done for investigating the recharge source of it. The most common understanding was that the leakage of Jinghe was the main recharge source for Shaizhudong Spring which is the concentrated discharge point of hidden karst system in the catchment area of Shaizhudong Spring. However, with the method of hydrogen and oxygen isotopes, and combining the condition of hydro-geochemistry and karst hydro-geology, we have different opinions on the recharge source of Shaizhudong Spring. This study shows the result that the recharge of Shaizhudong Spring is given priority by karst groundwater which is outside the southwest of the Shaizhudong Spring area.

Abstract: In arid and semi-arid areas, groundwater has been the main source of water supply for large cities and towns over several decades. With long-term withdrawals, a cone of depression in confined aquifer has formed over twenty years in Yinchuan area. The evolvement characteristics indicate that the cone of depression region is facing serious problems which are related not only to groundwater quantity but also to water deterioration. Water level decline is inevitable with well abstraction for confined aquifer owing to increasing water demand, and then phreatic water leakage recharge may accelerate deterioration with poor water quality. Therefore, the cone of depression plays an observable role in confined water protection as to groundwater sustainable utilization.

Abstract: Ecological compensation is being applied to deal with transboundary external effects caused by water resources conservation or exploitation in China. A concept of water resources co-conservation and sharing was applied to burden the upstream conservation cost and to share the benefit in the whole river basin. Xin’an River Basin, related to two provinces in East China, was taken as the study area. The current territorial scales of the co-conservation area and the benefit sharing area were determined. The total actual water conservation cost for Xin’an River Basin was estimated to be about 488 million CNY in 2006. By analyzing the transformation of protection costs and benefits between different districts and sections, benefits brought by water to different beneficiaries were also estimated. The conservation cost was distributed to the water users or governments in the whole sharing area according to the proportion of shared benefits.

Abstract: According to the low accuracy of velocity filed in current software, we develop a new system to analyze and visualize the 3D groundwater flow field. We employ the most advanced algorithm to deal with the data form groundwater simulation. The system could compute the flux across arbitrary face and the velocity of arbitrary point in the research domain. The system is debugged in Microsoft Visual Studio. The interactive interface is developed in .Net and the visualization tool is OpenGL. The application shows that the system is robust.