小流域产流产沙动力学模型

按自然水系划分单元,每一单元又被概化为“一本打开的书”概化后的单元又区分为几个微地貌区。各单元水沙过程演算至流域出口迭加得流域产流产沙过程。此法一方面解决了降雨,侵蚀和下垫面的不均匀性,另一方面又解决了水沙的演算问题。坡面和沟道水流用运动波方程描述并用四点隐式差分格式求其数值解。根据水流作功和能量平衡原理推导出各微地貌区上的土侵蚀量计算公式,建立起具有物理过程基础的小流域产流产沙模型。     

A Simple Conceptual Model of Sediment Yield

The sediment graphs (time distribution of sediment yield) are very essential if the sediment transports the pollutants that are toxic at high concentrations, requiring determination of peak, rather than average sediment flow rate. In this paper, an effort has been made to develop a simple conceptual model of sediment yield based on Soil Conservation Service Curve Number (SCS-CN) method, instantaneous unit sediment graph (IUSG) method, and Power law and the performance is tested using real field data of Chaukhutia watershed of Ramganga river catchment (area = 452.25 km²). The proposed model is found to provide realistic estimates of temporal variation of sediment yield as well as total sediment yield during a storm event. The model is found to be most sensitive to parameter β followed by k, \upalpha\upalpha, A, and n_s. A comparison is made with the existing IUSG based models of Kumar and Rastogi (J Hydrol 95:155–163, 1987) and Raghuwanshi et al. (J Hydraul Eng ASCE 120(4):495–503, 1994) for developing sediment graphs.     

A Model for Optimal Allocation of Water to Competing Demands

The present study develops a simple interactive integrated water allocation model (IWAM), which can assist the planners and decision makers in optimal allocation of limited water from a storage reservoir to different user sectors, considering socio-economic, environmental and technical aspects. IWAM comprises three modules—a reservoir operation module (ROM), an economic analysis module (EAM) and a water allocation module (WAM). The model can optimize the water allocation with any of two different objectives or two objectives together. The two individual objectives included in the model are the maximization of satisfaction and the maximization of net economic benefit by the demand sectors. Weighting technique (WT) or simultaneous compromise constraint (SICCON) technique is used to convert the multi-objective decision-making problem into a single objective function. The single objective functions are optimized using linear programming. The model applicability is demonstrated for various cases with a hypothetical example.     

半湿润流域蓄满超渗空间组合模型研究

半湿润流域蓄满产流与超渗产流兼有,如何区分两种不同性质的产流过程一直是水文预报的难题。基于主导性水文过程的概念,结合遥感技术与地理信息技术,采用水文学界应用广泛的CN值和地形指数指标,划分蓄满产流主导区与超渗产流主导区,提出了蓄满超渗空间组合模型。以东湾流域为例,验证了蓄满产流模型、超渗产流模型及蓄满超渗空间组合模型的模拟效果。结果表明:单一产流模型参数失真,蓄满超渗空间组合模型参数接近实际;蓄满产流与超渗产流主导区划分越精确,参数越合乎实际;蓄满超渗空间组合模型精度较高,验证期结果稳定。     

水库水沙优化调度

摘 要:针对水沙优化调度多目标、高维和难以求解的特点,利用约束法将多目标模型转化为单目标模型,并采用全局搜索能力和收敛性较强的鲶鱼效应粒子群算法求解水沙优化调度模型.该算法利用鲶鱼效应对种群多样性的动态调节和驱赶作用,克服了粒子群容易陷入局部最优的缺点.实例验证表明,优化结果给出了较为满意的水库发电与泥沙淤积的非劣解集及水库非劣运用过程,算法具有有效性和通用性.     

城市黑臭水体底泥处理技术的比选研究

城市黑臭水体底泥的治理是水污染防治的重要环节。笔者在广泛调研国内外底泥处理技术现状的基础上,从底泥中重金属的去除、底泥脱水、余水处理3个方面,研究了黑臭水体底泥处理可采用的技术方案,探讨了各类处理技术的优缺点,提出了选择最佳处理方案需要综合考虑的影响因素。     

Optimal Design of Concrete Canal Section for Minimizing Costs of Water Loss,Lining and Earthworks

Canal section design with minimum cost, which can be considered as an objective function, involves minimization of total costs per unit length of the canal, including direct costs of per cubic meter earthworks and per meter canal lining and indirect costs of water losses through canal seepage and evaporation. Since the costs (both direct and indirect) are associated with the canal geometry and dimensions, it is possible to lower them by optimization of the mentioned objective function. For this purpose, some constraints were subjected and considered to solve the problem. Flow discharge, as the main constraint, was considered in addition to the minimum permissible velocity and Froude’s number, as subsidiary constraints. MATLAB programming software was used to demonstrate and run the optimization algorithm. The results finally were illustrated in forms of dimensionless graphs, which simplify the optimum design of canal dimensions with minimum cost per meter length. Comparing the results with other similar studies, however show the importance and role of earthworks and lining costs, as well as including the subsidiary constraints in the optimization process.     

Similarity-Based Optimal Operation of Water and Sediment in a Sediment-Laden Reservoir

Reservoir sedimentation is a severe problem because it leads to the loss of reservoir storage capacity. Therefore, the sustainable management of water and sediment constitutes a critical measure in reservoir operation. In this research, a model of similarity-based operation method of water and sediment which can improve the efficiency of reservoir operation strategies is presented. Two parts comprise this method: a similarity-based forecasting model for the sediment process at the dam, and a new operation mode of water and sediment based on the sediment process at the dam. The similarity-based forecasting model is built on the total flow model of water and sediment, which requires less data. Using the similarity among flood cases, the parameters of the model are calibrated by group, and are dynamically selected, an approach which enforces the suitability of parameters and improves the forecasting accuracy. In terms of the sediment process at the dam, the proposed optimal operation model of water and sediment improves the sediment-venting efficiency and saves the water resource.     

Utility of Ten-Day Climate Model Ensemble Simulations for Water Resources Applications in Korean Watersheds

We demonstrate the use of a quantitative measure of the effectiveness of using climate model simulations of surface precipitation and temperature for water resources applications involving extremes of watershed average precipitation and temperature, and watershed discharge. This diagnostic measure is considered in association with the use of climate information to condition ensemble seasonal predictions of watershed variables. Seven watersheds in the Korean peninsula constitute the application sites. The climate model effectiveness is expressed by a utility index E_P that measures the ability of the climate model simulations of an indicator variable (i.e., nodal precipitation or temperature) to discriminate observed distributions of the highs and lows of a watershed target variable (i.e., mean areal precipitation and temperature as well as outlet discharge). Monte Carlo simulations provide estimates of the significance of the E_p values. For apparently the first time, ten-member ensemble simulations of daily surface precipitation and temperature from the Korean Meteorological Agency climate model are used to evaluate the climate-model utility index E_P for a temporal interval of 10 days for each application watershed. The results show that, in spite of the high uncertainty of climate simulations, there are several Korean watersheds that can benefit from the use of climate model simulations of high temporal resolution for planning and management studies that involve precipitation, temperature and discharge. In particular, seasonal ensemble prediction of watershed variables stands to gain from conditioning on high-temporal resolution climate forecasts.     

皇甫川流域产流产沙数学模型及水沙变化原因分析

该模型是从泥沙运动力学的基本理论出发，结合水文学，气象，土壤学和地理地貌学的原理建立起来的。并着重解决了在大流域计算中的流域的地理，地貌的差异性和降雨在时空分布上的不均匀性问题。     

基于地块间水沙运移的黄土丘陵沟壑区小流域侵蚀产沙模型

根据黄土丘陵沟壑区的侵蚀产沙规律，在晋西羊道沟小流域建立了坡面、沟坡和沟道侵蚀产沙子模型；在GIS的支持下计算出小流域地块间水沙汇流网络，并引入到小流域侵蚀产沙模型中，使小流域侵蚀产沙成为有机结合；模型对羊道沟22次侵蚀性降雨的侵蚀模数具有78．4％的预报精度，对羊道沟1956－1970的年侵蚀模数具有76．1％的预报精度；模型并通过了晋西汾河上游两个小流域的可移植性检验。     

大规模供水系统优化调度的建模方法

根据给水系统的网络特性 ,并结合我国实际情况 ,对优化调度控制方法进行了系统的分析 ,针对隐式模型 ,提出了分级优化方法 ,特别是根据含调速泵供水系统的特点 ,提出了优化调度策略 ,并进行了实际城市的应用 ,证明了其实用性。     

A Decision Model for Identifying and Solving Problems in an Urban Water Supply System

Water Resources Management - Water supply systems in urban areas may become deficient due to increasing demand, which accompanies population growth but is further jeopardized by equipment aging and...     

The Optimal Reuse of Reclaimed Water: A Mathematical Model Analysis

As recycling effluent from municipal sewage plants is technically a feasible way, this paper presents a mathematical model to analyze the extent to which effluent should be reclaimed for industrial use and examine the factor affecting reuse of reclaimed water. The resulting data shows that the low price of fresh water leads to reduced use of reclaimed water and impedes the investment of the effluent purification plant. A mandated regulation on the substitution rate of reclaimed water is suggested to impose on the industry. Theoretically, the optimal substitution rate as well as the water quality is determined by maximizing the total social welfare that results from the construction of conveyance channels and effluent purification plants. A case example is employed to derive the optimal substitution rate and water quality of reclaimed water. Through the numerical analysis, an effluent plant for treating 20,000 kl/day effluent with the substitution rate of 21.24 % is selected as the optimal solution.     

泥沙模型试验浑水系统的研制及应用

介绍了多沙河流游荡性河段整治工程措施试验研究课题中浑水系统的研制过程。通过试验证明该套浑水系统具有水力搅拌、宽水槽、不落淤、经济合理等特点 ,该套浑水系统可推广应用到其它浑水模型试验中。     

A Double-Layer Dynamic Differential Game Model for the Optimal Trading Quantity of Water and Price Setting in Water Rights Transactions

Water Resources Management - The increase in water demand due to industrial development and agricultural expansion and the need for ecosystem improvement call for the efficient, equitable and...     

无坝引水防沙措施述评

对有关无坝引水防沙方面的文献资料进行分析总结,从引水口位置的确定、引水角度、引水闸底高程、分流比、引水防沙设施、排沙设施等方面阐述如何尽量减少泥沙淤积,以期为工程实践提供参考.     

Modeling of Sediment Yield Prediction Using M5 Model Tree Algorithm and Wavelet Regression

The forecast of the sediment yield generated within a watershed is an important input in the water resources planning and management. The methods for the estimation of sediment yield based on the properties of flow and sediment have limitations attributed to the simplification of important parameters and boundary conditions. Under such circumstances, soft computing approaches have proven to be an efficient tool in modelling the sediment yield. The focus of present study is to deal with the development of decision tree based M5 Model Tree and wavelet regression models for modeling sediment yield in Nagwa watershed in India. A comparison is also performed with the artificial neural network (ANN) model for streamflow forecasting. The root mean square errors (RMSE), Nash-Sutcliff efficiency index (N-S Index), and correlation coefficient (R) statistics are used for the statistical criteria. A comparative evaluation of the performance of M5 Model Tree and wavelet regression versus ANN clearly shows that M5 Model Tree and wavelet regression can prove more useful than ANN models in estimation of sediment yield. Further, M5 model tree offers explicit expressions for use by design engineers.     

Finite Element Method and GIS Based Distributed Model for Soil Erosion and Sediment Yield in a Watershed

The objective of this study is to develop a soil erosion and sediment yield model based on the kinematic wave approximation using the finite element method, remote sensing and geographical information system (GIS) for calculating the soil erosion and sediment yield in a watershed. Detachment of soil particles by overland flow occurs when the shear stress at the surface overcomes the gravitational forces and cohesive forces on the particles. Deposition occurs when the sediment load is greater than the transport capacity. Beasley et al.’s (Trans ASAE 23:938–944, 1980) transport equations for laminar and turbulent flow conditions are used to calculate the transport capacity. The model is capable of handling distributed information about land use, slope, soil and Manning’s roughness. The model is applied to the Catsop watershed in the Netherlands and the Harsul watershed in India. Remotely sensed data has been used to extract land use/land cover map of the Harsul watershed, and other thematic maps are generated using the GIS. The simulated results for both calibration and validation events are compared with the observed data for the watersheds and found to be reasonable. Statistical evaluation of model performance has been carried out. Further, a sensitivity analysis has also been carried out to study the effect of variation in model parameter values on computed volume of sediment, peak sediment and the time to peak sediment. Sensitivity analysis has also been carried out for grid size variation and time step variation of the Catsop watershed. The proposed model is useful in predicting the hydrographs and sedigraphs in the agricultural watersheds.     

Factors Controlling the Suspended Sediment Yield During Rainfall Events of Dry and Wet Weather Conditions in A Tropical Urban Catchment

Water Resources Management - The catchments of the Klang and Ampang Rivers are two sub-catchments that drain into the main Klang River, Selangor, Malaysia. Due to the development and siltation...