Applied Mechanics and Materials Vols. 641-642

Abstract: The flow field variation and the riverbed deformation of Chengde reaches of Luanhe river before and after the construction of the embankment and dam engineering were studied by the river model test. The results showed that the dike layout was reasonable, the designed erosion control measures can resist the local scour, and the dam reduced the scouring. So the maximum erosion depth near the left and right dike was decreased by 3.0m and the average depth reduction was 0.9m. Under the dam project conditions, the deep scour pit at the dike toe with the maximum scouring depth of 4.0 - 5.0m was shaped. Such erosion control measures as the fuseplugspillway form is suggested to reduce the erosion significantly.

Abstract: A trial was conducted to investigate water sensitivity index (WSI) and water production function (WPF) of processing tomato subjected to water deficits in an arid environment. The WSI at various growth stages of processing tomato were maintained and a periodical WPF was established based on Blank model. The maximum WSI of processing tomato was marked at flowering with 0.7108 while the minimum was maintained at seedling with-0.0854. In addition, WSI was extremely lower at full fruiting compared to at flowering but notably higher than at seedling. Therefore, processing tomato was extremely sensitive to water deficit at flowering and high levels of soil moisture contents should be maintained while was not sensitive to water deficit at seedling and high levels of water deficits could be controlled without causing yield reduction.

Abstract: As for the level of tail-water often rose when the situation of tailrace river changing during the process of construction of hydroelectric power station, one-dimensional mathematical model is used through two procedures to solve this problem. In the first, the sensitivity of three key parameters including roughness, cross-section spacing Δs, starting regulation level and section in the mathematical model were discussed. The results indicate that: (1) Positive relationship between ΔY/Y and n, shows the greater flow rate, the more sensitive of water depth changes to roughness coefficient; (2) The cross-section spacing Δs affect the large flow more obvious than the smaller; (3) The effect of the middle and lower reaches of river are bigger than the upstream. Research results provided guidance of model parameters selection.

Abstract: According to datas of Sanmenxia Reservoir and physical model test of Xiaolangdi Reservoir during later sediment retaining period, the paper study evolvement of high beach and deep channel of reservoir in the sediment-laden rivers. The results show that: 1The evolution of high beach and deep channel is as follows, firstly, beach and channel increase synchronously , and then scour happens in channel. Channel scour and scour amount is crucial to form high beach and deep channel. 2It is found that tributaries were equivalent to the horizontal extension of mainstream riverbed. The deposition process of tributary is closely related to many factors of natural topographic condition, deposition morphology of mainstream at the confluence area of mainstream and tributary and so on. The cross-section of tributary kept uplift horizontally, and sand bar has formed in some tributary estuary. 3Rainfall erosion formed in flood period is beneficial to forming hyper-concentrated flow, to a certain extent; it can recover channel storage capacity, and play an important role on utilizing long-term comprehensive benefits. Studying evolvement of high beach and deep channel can supply some technical supports for regulating operational mode of Xiaolangdi Reservoir during later sediment retaining period and prolonging service life.

Abstract: Based on the water balance and solute mass conservation, a simple two-layer incomplete mixing model by Tong et al. (2009) is used to study adsorptive solute of Cr (VI) loss from soil into surface runoff with nonlinear Temkin adsorption. Laboratory experimental data are used to verify the model with nonlinear Temkin isotherm adsorption equation. Study results suggest that model simulations with Temkin isotherm equation agree well with the observed data, which means that the model is valid. The sensitivity of the model parameters were analyzed, which shows that the mixing parameters γ and α are more sensitive to the soil solute of Cr (VI) loss to surface runoff while the parameter B₁ and A₁ of adsorption equation is less sensitive. The solute of Cr (VI) loss to surface runoff is decreasing with increasing θ₀, while soil bulk density is vice verse. The study results will provide references to prevent soil solute of Cr (VI) pollution to surface water system.

Abstract: Optimization irrigation schedule can effectively improved the water use efficiency and the crop yield, and it uses the ISAREG model to study the optimization irrigation schedule of winter wheat based on the actual field test data in Hetao Irrigation District. The results showed that: the problems of irrigation quota and irrigation time are unsuitable through analyzed the actual irrigation schedule by calibrated and verified parameters; the optimization irrigation schedule of winter wheat is obtained on the basis of combines design different irrigation quota and irrigation time for the water requirement characteristics.

Abstract: The radial sand ridges located in the southern Yellow Sea off the Jiangsu coast, are unique sand ridges. They are characterized by radical current field and radical arrangement. The formation and maintenance mechanism of the radial sand ridges have always been a focus of attention of scholars for a long time. The formation is related to the unique convergent-divergent tidal currents. In this paper, a numerical model is constructed to answer the two following questions. Firstly, can the radial sand ridges be formed with radical tidal current field Secondly, can this be simulated by a numerical model The radial tidal current can shape the radial sand ridges. Numerical simulations show that the radial sand ridges can be formed on present radical tidal current field and the formation and evolution of the radial sand ridges can be simulated by a numerical model.

Abstract: The upper Yangtze river rare and endemic national nature reserve was set up to protect the rare and endemic fish. Affected by the cascade development of the downstream reach of the jinsha river, fish habitat in the national nature reserve have been changed significantly, which will affect the reproduction and growth of the fishes.The Coreius heterodon spawning grounds were located in the Main stream of the natural reserve, andits spawning season needs certain overflowing process to lay eggs. This article used the water level and flow data from 1956 to 2012 in the Zhu Tuo stationto analysis the eco-hydrologicaldemand for Coreius heterodon breeding. and this result can provide the reference for the ecological operation of cascade reservoirs in the downstreamof jinsha river.

Abstract: The series hydraulic softwares of HEC-RAS is a set of softwares volumes with strong functions and broad uses in overseas. They play an important part in river hydraulic analysis、hydrology simulation、flood forcasting、river renovation and reservoir managition and programmings.The paper introduces the composition and the function of HEC-RAS model, a one-dimensional steady and unsteady flow models were established.Using this model, the designing water surface is analogized, its operation pattern is discussed, water surface profile of some water supply works are simulated.The result indicates that the application of HEC-RAS is simple and convenient,its applicability is good.

Abstract: Based on the investigation and indoor experiment, the flow structure and properties of erosion or deposition associated with permeable spur dike were researched. According to the new demands about engineering structure in mountain rivers regulation, the potential action of permeable spur dike in mountain river training was analyzed. The results can be showed that, as the permeable structure, the influence of permeable spur dike to main flow and flood level is less than the solid one, and the local scour depth is less too, so the permeable spur dike has larger safety. In the back of permeable spur dike, it can form a slow flow field, instead of a circumfluence field, and the deposition volume is less than solid one, so the steady slow flow field can benefit to the small aquatic animal lives. The pervious rate can be adjusted to complete training goals when the project faces to different training demands. And the material of spur dike is not limited, it can use the local materials to build, which can reduce the construction cost. The permeable spur dike have a good applicability in the control of mountain river, it can meet the requirements of flood prevention, ecology, environment, cost saving and so on, it have a greatly application prospect.