Optimal Water Resources Management: Case of Lower Litani River, Lebanon

The pressures of human population and patterns of development frequently jeopardize the integrity of river systems worldwide. An integrated approach to water resources management is essential, particularly in developing countries. This study presents the results of the water resources optimization conducted for the Lower Litani River Basin in Lebanon. The overall aim of the project is to develop, test, and critically evaluate an innovative approach to water resources management in the Mediterranean region. The method explores the ways in which multiple environmental, economic, and social benefits can be achieved through integrated management of water resources. The Water Resources Model was utilized to assess the efficiency of the baseline model scenario and for the optimization process of the different scenarios of the Litani Lower Basin. Strengths, weaknesses, opportunities and threats analysis was applied in order to derive the objectives and constraints. Results revealed that the potential retained scenarios aim at decreasing water consumption and demand, losses, and return flow. These scenarios mainly include the shift to drip irrigation, awareness campaigns, and losses control in domestic supply pipes. Other retained scenarios having a higher shortfall rely on the use of the Channel concrete lining to decrease losses and return flow, in addition to the awareness campaigns in both domestic and irrigation sectors, and less consumptive/more efficient irrigation methods such as sprinkler and drip irrigation at variable application percentages. Hence, most of the interventions or measures proposed are generally not costly and can be implemented.     

Incorporating Eco-environmental Water Requirements in Integrated Evaluation of Water Quality and Quantity—A Study for the Yellow River

River water has dual functions; it can be withdrawn for agricultural, industrial, and domestic uses and provides eco-environmental water (EEW) for riverine systems. A concept of intensity of ecological function of river water (IEFRW) has been put forward, and an integrated water quantity and quality evaluation method in combination with eco-environmental water requirements has been developed for a river. Based on the monthly data of water quality and quantity as well as the withdrawals during 1997 to 1999, an integrated evaluation of water resources has been conducted for the Yellow River. The results indicated that actual IEFRW can directly reflect the health state of riverine ecosystems. The actual increments of water resources availabilities caused by providing EEW for the riverine systems were lower than the eco-environmental water requirements of the riverine ecosystem, leading to the intermittent interruption of river flow and other eco-environmental problems of the Yellow River.     

Impacts of Climate Change on Water Resources Availability and Agricultural Water Demand in the West Bank

Global climate change is predicted as a result of increased concentrations of greenhouse gasses in the atmosphere. It is predicted that climate change will result in increasing temperature by 2 to 6°C and a possible reduction of precipitation of up to 16% in the Mediterranean basin. In this study, the West Bank is taken as a case study from the Mediterranean basin to evaluate the effects of such climate change on water resources availability and agricultural water demands. Due to the uncertainty in climate change impacts on temperature and precipitation, a number of scenarios for these impacts were assumed within the range of predicted changes. For temperature, three scenarios of 2, 4 and 6°C increase were assumed. For precipitation, two scenarios of no change and 16% precipitation reduction were assumed. Based on these scenarios, monthly evapotranspiration and monthly precipitation excess depths were estimated at seven weather stations distributed over the different climatic and geographical areas of the West Bank. GIS spatial analyses showed that the increase in temperature predicted by climate change could potentially increase agricultural water demands by up to 17% and could also result in reducing annual groundwater recharge by up to 21% of existing values. However, the effects of reduced precipitation resulting from climate change are more enormous as a 16% reduction in precipitation could result in reducing annual groundwater recharge in the West Bank by about 30% of existing value. When this effect is combined with a 6°C increase in temperature, the reduction in groundwater recharge could reach 50%.     

大型渠道混凝土衬砌振捣滑模成型机的工作机理及设计

针对南水北调引水渠工程建设对渠道衬砌采用机械化的需求,通过分析渠道混凝土密实衬砌成型机理,开发出了一种大型渠道混凝土衬砌振捣滑模成型机。设备主要有行走装置、升降装置、布料装置、振捣装置、滑模成型装置、电控系统等部分组成。可一次完成渠道混凝土布料、振捣密实、提浆、挤压成型等工作,自动完成对斜坡、坡脚、坡肩的衬砌。设备具有自动控制、自动平衡、自动监测功能,自动化程度高。和国外先进设备相比,本设备结构简单,性价比高,适应性强,整机技术居国际领先水平,很好的满足了南水北调工程建设的要求。     

南水北调中线总干渠新乡潞王坟段膨胀岩渗透性研究

为了解南水北调中线一期工程总干渠试验段膨胀岩的基本特性,开展了膨胀岩的现场渗透试验.对比分析采用Guelph渗透仪和双套环对黏土岩和泥灰岩测得渗透系数.结果表明,泥灰岩渗透系数范围在10-4～10-6 cm/s 之间,黏土岩渗透系数范围在10-5～10-6 cm/s之间,测试结果基本反映了岩体渗透性能.     

上海市北大型给水管网模型的建立

上海市自来水市北有限公司根据管网管理需要建立管段数约20万的大型管网模型系统.系统介绍了建立模型所需数据的收集与整理,以及模型建立工程.模型经过校核和调试,目前已在管网规划、现状评估、预案模拟等多项工作中得到应用.以市北闸北水厂停役为例具体讲述了模型的应用.     

三峡机组招标文件的特点剖析

三峡工程左岸电站14台单机容量700MW水轮发电机组实行国际招标，招标文件突出了三峡机组的特殊运行要求；体现了当前该领域的先进水平；突出了三峡机组招标采购的特定的时空特点；在商务、融资、技术转让、国内外企业合作方面作出了明确的表达。     

三峡工程导流底孔设计研究

三峡工程导流底孔跨缝布置于泄洪坝段共２２个，主要承担三期施工导流任务并在三期围堰挡水发电期间，与泄洪深孔联合泄洪。导流底孔运用３年后封堵，并回填。导流底孔布置上受因素多，运用条件变化大，孔口作用水头高结构受力复杂。因此对导流底孔的水力设计，结构设计，防泥沙磨损措施和     

三峡工程二期围堰平抛垫底施工

三峡二期围堰是在葛洲坝水库中施工的，水深大，流速低，决定采用预平抛垫底措施，以减少围堰进占水深和堤头滑坍。对河床高程低于４０ｍ的深槽部位，采用沙砾料，石渣及块石抛垫底，设计总投抛量约９８．８万ｍ＾３，为了施工和通航互不干挠分左，右区，一区施工，另一区通航。     

临时船闸及升船机 基岩开挖 喷混凝土施工

三峡工程临时船闸及升船机全长４．６ｋｍ，并列布置，下游共用引道。在△↓８４ｍ由平均宽２３ｍ的中隔墩岩体分开。基岩为前震旦纪粗粒闪云斜长花岗岩。总开挖量１４５６万ｍ６３，承裂爆破长３８．２２万ｍ＾２，边坡喷护面积２１．２万。升船机△↓９５ｍ平 用水平预裂法开挖；中隔墩开挖采用深孔大孔距小低抗线孔间微差爆破，两侧保护层开挖采用爆破。