清江流域水布垭水库二氧化碳大气廓线空间分布及其水环境效应

为了研究水库水体二氧化碳源汇变化时空分布格局及其影响因素,选择清江流域水布垭水库为典型示范案例,在2010年5月8日到9日开展了二氧化碳观测实验,获取了水库上空大气二氧化碳浓度垂直变化以及沿水库中心线二氧化碳浓度的变化特征。然后基于地理信息系统空间分析技术对观测点二氧化碳浓度数据进行空间插值计算,得到整个水库水体的空间分布特征,并与水环境因子空间分布情况进行比较分析。研究结果表明：水布垭水库上空大气二氧化碳浓度在05 m高度以下最高,然后向上依次降低,其空间分布从水库上游到坝前呈现增加的趋势。同时水库水体二氧化碳浓度变化受到表层水温、叶绿素浓度等水环境重要因素的影响,与水温和气温呈负相关关系,而与叶绿素呈正相关关系     

门楼水库总氮环境容量计算及其总量控制方案研究

文中分析了门楼水库的总氮污染状况,提出了门楼水库总氮环境容量的计算原则、设计水文条件和水质保护目标,为改善市区居民的饮用水质量,保障市民的身体健康,制定合理的污染控制方案,提供了科学的参考依据。     

长江三峡水库诱发地震问题的分析研究

三峡水库是长江干流上一个巨型水利工程,拟定坝高１８５ｍ,正常蓄水位１７５ｍ,防洪库容２２１．５０亿ｍ＾３。三峡工程涉及的地质问题很多,水库诱发地震是其中主要要研究的几个问题之一。本文按三峡库萄 地质条件,将三峡库区分为三个库段进行讨论并采用灰色系统理论聚类分析的方法,对其诱发地震的强度进行了预测,认为三峡水库诱发地震的最危险库段的庙河－奉节段,其强度可达５．０￣６．０级。     

PARAMETER UNCERTAINTY IN RAINFALL-RUNOFF MODELING FOR POLDER SYSTEM DESIGN1

ABSTRACT: An approach is developed for incorporating the uncertainty of parameters for estimating runoff in the design of polder systems in ungaged watersheds. Monte Carlo Simulation is used to derive a set of realizations of streamflow hydrographs for a given design rainstorm using the U. S. Soil Conservation Service (SCS) unit hydrograph model. The inverse of the SCS curve number, which is a function of the antecedent runoff condition in the SCS model, is the random input in the Monte Carlo Simulation. Monte Carlo realizations of streamfiow hydrographs are used to simulate the performance of a polder flood protection system. From this simulation the probability of occurrence of flood levels for a particular hydraulic design may be used to evaluate its effectiveness. This approach is demonstrated for the Pluit Polder flood protection system for the City of Jakarta, Indonesia. While the results of the application indicate that uncertainty in the antecedent runoff condition is important, the effects of uncertainty in rainfall data, in additional runoff parameters, such as time to peak, in the hydraulic design, and in the rainfall-runoff model selected should also be considered. Although, the SCS model is limited to agricultural conditions, the approach presented herein may be applied to other flood control systems if appropriate storm runoff models are selected.     

SEASONAL ARIMA INFLOW MODELS FOR RESERVOIR SIZING1

ABSTRACT: The reliable sizing of reservoirs is a very important task of hydraulic engineering. Although many reservoirs throughout the world have been designed using Rippl's mass curves with historical inflow volumes at the dam site, this technique is now considered outdated. In this paper, synthetic series of monthly inflows are used as an alternative to historical inflow records. These synthetic series are generated from stochastic SARIMA (Seasonal Autoregressive Integrated Moving Average) models. The analyzed data refer to the planned Almopeos Reservoir on the Almopeos River in Northern Greece with 19‐year monthly inflow series. The analysis of this study demonstrates the ability of SARIMA models, in conjunction with the adequate transformation, to forecast monthly inflows of one or more months ahead and generate synthetic series of monthly inflows that preserve the key statistics of the historical monthly inflows and their persistence Hurst coefficient K. The forecasted monthly inflows would be of help in evaluating the optimal real time reservoir operation policies and the generated synthetic series of monthly inflows can be used to provide a probabilistic framework for reservoir design and to cope with the situation where the design horizon of interest exceeds the length of the historical inflow record.     

RIVERWARE: A GENERALIZED TOOL FOR COMPLEX RESERVOIR SYSTEM MODELING1

ABSTRACT: Water management agencies seek the next generation of modeling tools for planning and operating river basins. Previous site‐specific models such as U.S. Bureau of Reclamation's (USBR) Colorado River Simulation System and Tennessee Valley Authority's (TVA) Daily Scheduling Model have become obsolete; however, new models are difficult and expensive to develop and maintain. Previous generalized river basin modeling tools are limited in their ability to represent diverse physical system and operating policy details for a wide range of applications. RiverWare(tm), a new generalized river basin modeling tool, provides a construction kit for developing and running detailed, site‐specific models without the need to develop or maintain the supporting software within the water management agency. It includes an extensible library of modeling algorithms, several solvers, and a rich “language” for the expression of operating policy. Its point‐and‐click graphical interface facilitates model construction and execution, and communication of policies, assumptions and results to others. Applications developed and used by the TVA and the USBR demonstrate that a wide range of operational and planning problems on widely varying basins can be solved using this tool.     

OPTIMAL CONTROL OF RESERVOIR RELEASES TO MINIMIZE SEDIMENTATION IN RIVERS AND RESERVOIRS1

ABSTRACT: An optimal control methodology and computational model are developed to evaluate multi‐reservoir release schedules that minimize sediment scour and deposition in rivers and reservoirs. The sedimentation problem is formulated within a discrete‐time optimal control framework in which reservoir releases represent control variables and reservoir bed elevations, storage levels, and river bed elevations represent state variables. Constraints imposed on reservoir storage levels and releases are accommodated using a penalty function method. The optimal control model consists of two interfaced components: a one‐dimensional finite‐difference simulation module used to evaluate flow hydraulics and sediment transport dynamics, and a successive approximation linear quadratic regulator (SALQR) optimization algorithm used to update reservoir release policies and solve the augmented control problem. Hypothetical two‐reservoir and five‐reservoir networks are used to demonstrate the methodology and its capabilities, which is a vital phase towards the development of a more robust optimal control model and application to an existing multiple‐reservoir river network.     

天目湖水质演变及富营养化状况研究

为了解长江中下游地区濒临城市的湖泊型水库富营养化情况并在此基础上提出治理对策,选择了具有代表性的旅游景区天目湖（沙河水库）为研究对象,在2006年对其水质情况进行了每月1次的周年调查, 2007年5月～2007年12月又进行了隔月1次的水质调查. 2006年调查结果表明,水体总氮（TN）和总磷（TP）的平均浓度分别为1.49 mg/L和0.06 mg/L,较2001～2002年分别增长了2.7倍和2.0倍;水体高锰酸盐指数的平均值为3.68 mg/L,比2001～2002年稍有增加;水体透明度（SD）的平均值为1.2 m,比2001～2002年下降了25 cm, 2006年藻类生物量平均值为46.39 mg/L.天目湖已经由2001～2002年的中-中富营养化状态转变为2006年的中富营养化状态.根据2006年水质调查结果以及沉积物、渔业生产、浮游生物、底栖生物等综合调查结果提出并实施了天目湖的治理方案,即必须采取措施控制农业面源、入湖河流、旅游业等外源性污染以及降低水土流失造成的入湖悬浮物质含量以提高水体透明度,从湖泊外源、内源以及湖泊生态系统的物质循环三者之间的关系着手制定天目湖治理方案. 2007年水体TN的平均浓度为1.25 mg/L;TP平均浓度为0.05 mg/L;藻类生物量平均值为22.56 mg/L. 2007年的再次调查结果表明这些措施的实施对水体营养盐含量以及浮游生物量的降低已初见成效.     

Effects of Flooding on Lead and Cadmium Speciation in Sediments from a Drinking Water Reservoir

Římov water reservoir on the river Malše is the main source of drinking water for the town of České Budějovice and for the majority of inhabitants in the South Bohemian region, Czech Republic. Changes in cadmium and lead contents in bottom sediments before and after an extensive flood on the river Malše in August, 2002 were therefore determined. A five-step sequential extraction procedure was used in order to obtain more detailed information about the influence of the flood on heavy metal retention. In order to determine the mobility of lead and cadmium, the mobility factor (MF) for these heavy metals was calculated. The mobility factor of cadmium showed a significant decrease in the upper parts of the sediment profiles after the flood (e.g., from 59.4% to 49.1%) caused by a release of cadmium especially from the exchangeable fraction. There were no significant changes in the lead mobility factor after the flood, but a decrease of lead concentration in the exchangeable fraction was observed. Presented results show that the flood led to a leaching of the heavy metals present in bottom sediments into the environment.     

Variation of Metals in Bed Sediments of Qaraaoun Reservoir, Lebanon

The Qaraaoun Reservoir (impoundment of the River Litani) is the only artificial surface water body in the country, Lebanon. Earlier study on the water quality of the Qaraaoun Reservoir identified three water quality zoning with a central distinct zone suitable for multipurpose water usage. The objective of this study was to extend the earlier work by considering the total metal content of reservoir bed sediments and hence to evaluate factors that control metal deposition or capture. Water samples were collected from 15 sampling sites and sediment samples were simultaneously collected from 9 sites. Water parameters analyzed were pH, Eh, DO and temperature. Sediment samples were dried and sieved and sediment < 75 μ m was retained for analysis. Sediments were subjected to a stepwise heating process with aqua regia to extract the metals, and their content in sediments determined by ICP-MS. The sediment data revealed higher metal contents where the river entered the reservoir which matched higher concentrations of water parameters at the influx site. Regression analysis of total metals in sediments with distance from the river Litani influx point to the dam revealed a log trend for Fe, Cr and Ni, whereas, the concentrations of Cu, Zn, Cd, Pb were better described by a polynomial regression. Three sediment zones were identified: entrance, oxidation (central) and reducing (near dam) zones. Sediment contents of Zn, Cu and Pb correlated with organic content, whereas sediment Cr and Ni were associated with iron. It was concluded that sediments act as a sink for metals and the deposition of metals is primarily related to sediment organic content and the level of dissolved oxygen in water.