Lake Turkana,major Omo River developments,associated hydrological cycle change and consequent lake physical and ecological change

This study aimed to explore Lake Turkana's ecological reliance on hydrology and to determine the hydrological changes and consequences arising from the major hydropower and irrigation developments in the lake's basin. The major developments on Ethiopia's Omo River are especially significant as this river provides over 80% of the lake's annual freshwater influx and associated nutrients. The cascade of hydropower dams permanently dampens the natural hydrological cycles and lake level variability. The driving force of the flood influx to the lake is curtailed and the pattern of lake currents will adjust. Ultimately 80% of the river inflow to the lake will be regulated. Large volumes of water are required to initially fill the hydropower dam reservoirs. During 2015–16 when the huge Gibe III reservoir was filled, Lake Turkana's water level declined 2?m.The study has shown that large-scale irrigation schemes in the Lower Omo can potentially abstract 50% of the Omo River water, and that this would cause the lake level to shrink permanently to the detriment of the lake ecology. Possible lake level drops of over 15?m are demonstrated. The basin's natural capital is being replaced by large-scale plantation developments. The hydrological changes are drastic and the ecological consequences on Lake Turkana have not been fully understood. Without serious mitigation measures, Lake Turkana is a potential African Aral Sea disaster in the making, emulating what has happened to other great lakes such as Lake Chad.     

哈尼梯田灌区生态需水评价

针对云南省元阳县哈尼梯田灌区特点与实际情况,选用层次分析法和数据包络分析法,综合考虑自然、社会、水资源、生态环境等方面因素,建立生态需水评价模型,对灌区2000年和2005年的生态需水状况进行对比分析。结果表明,生物丰度指数、径流系数、植被覆盖指数、干旱指数4个指标为影响生态需水的重要指标,灌区2005年的生态需水状况比2000年有所改善,与灌区实际情况基本相符。     

竹塑复合材料在宁夏灌区末级渠系 衬砌中的应用研究

宁夏灌区末级渠系渠道衬砌率低,冻胀破坏和渗漏损失严重,灌区农业灌溉水利用系数仅为0.42。而且,灌区末级渠系的衬砌改造一直全部采用混凝土刚性材料进行防渗,存在的问题较多。为此,引进了技术先进、价格合理、适应性强的竹塑复合材料进行末级渠系衬砌,以改善灌区输水条件,延长衬砌工程使用寿命,实现水资源高效利用。本文从水力条件、节水效果、耕地占用、维修养护、施工速度等方面对传统混凝土渠道与竹塑复合材料衬砌渠道的特性进行了分析比较,并进行了相关综合经济效益评价。     

青铜峡灌区引黄用水与地下水位响应关系分析

分析青铜峡灌区引黄用水与地下水位响应关系,对于查明影响地下水位变化的关键因子并采取措施,缓解土壤盐碱化对农业生产的影响,维持灌区可持续发展及灌区生态健康和环境友好至关重要。本文通过分析灌区地下水位动态变化及与引黄用水的响应关系,得出青铜峡灌区年内地下水埋深与引黄水量存在着密切的负相关关系,说明灌区引黄水量变化是地下水位变化的主要原因之一。     

新时期汾河灌区可持续发展的思考

汾河灌区在山西省农业和社会经济发展中具有重要的地位,文中分析灌区水资源、骨干水利工程状况、末级渠系管理与建设、信息化发展以及生态环境方面存在的问题,结合水利现代化的要求提出相应对策,阐述了通过调蓄塘库群系统建设、节水改造和续建配套工程、末级渠系改造、灌区公用信息平台开发以及创新农户参与灌溉管理组织形式等途径可实现汾河灌区的可持续发展。     

Comparative Assessment of New Design Criteria for Irrigation Improvement in Egypt

The Egyptian Ministry of Water Resources and Irrigation (MWRI) has expressed concern about the current high cost of the Irrigation Improvement Project (IIP) implemented in the “old lands” of the lower reaches of the Nile River. Because the IIP is financed through fees paid by the direct beneficiaries of the project, i.e., irrigation water users, these same Egyptian agricultural producers are especially sensitive to the higher than expected costs that the project has incurred to date. The objective of the current study is to evaluate whether this cost reduction is associated with any deficiency in irrigation performance. This Monitoring and Evaluation (M&;E) study aims to answer questions such as: Does reducing pump capacity and increased pump operation affect the farmers negatively? And, does the use of electricity instead of diesel fuel affect the farmers positively? Six indicators were used to compare new design criteria in the W10 and the IIP1 irrigation system designs, water savings, irrigation cost, irrigation time, night irrigation, and land savings. The W10 project design achieved the minimum actual operating cost per unit of area and per unit of water compared to the IIP1 project design on both Meet Yazied and El-Mesk Canals. The total cost per unit of area in the W10 project design is lower than IIP1 by 19.33% and 24.92% on the Meet Yazied and El-Mesk Canals, respectively. The total cost per unit of water in the W10 design is also lower than IIP1 on the Meet Yazied and El-Mesk Canals. Average irrigation time for rice and cotton crops cultivated in the W10 area are higher than average irrigation time for these crops cultivated in the IIP1 area for all locations on the Mesqa (head, middle and tail), because of increased pump operation in the W10 area (16 to 20 h d^???1). The number of irrigation events at the head of the Sefsafa Canal in the W10 area is higher than on the Meet Yazied and El-Mesk Canals in the IIP1 areas because of the increased pump operation in the W10 area.     

浅谈发展节水灌溉，保持文峪河灌区的可持续发展

文峪河灌区水资源严重短缺，用水供需矛盾日益突出，经济效益呈逐年下降趋势。为此，发展节水灌溉，发挥水资源的最大效益，对于保持灌区经济的良性运行和可持续发展是必要的，也是势在必行的。     

潇河灌区渠系改造节水效益评析

潇河灌区经过近 5 0年的运行 ,渠系建筑物老化破损严重 ,灌溉水利用率极低。通过实施渠系改造工程 ,渠系水利用率由 0 .485提高到 0 .6 3,年节水量 70 4万m3,增加灌溉面积 8.6万亩次 ,节水效果明显 ,经济效益显著 ,保障了灌区的可持续发展     

桂中治旱乐滩水库引水灌区一期工程隧洞设计

乐滩水库引水灌区一期工程隧洞12座,总长为48.77 km,均为无压隧洞,针对隧洞从村屯附近穿越、长距离、低水头、大流量的特点,设计有针对性地提出了一些新观点。结合工程实际,从洞线选择、进出口布置、合理加大隧洞水深、减糙衬砌混凝土使用、TBM法施工应用等简述其设计要点。     

Improving water governance in Central Asia through application of data management tools

Contemporary water management decisions use many sources and forms of data. The paper discusses the implementation results of data management activities in the water sector carried out in five countries of the Central Asia region. Geoinformation systems, remote sensing tools and databases have been applied worldwide for improving water resources management with differing levels of success. Water management organisations, equipped with data management tools will have better capacities to adapt their decision-making in the changing availability and scarcity of water resources. Application of data management tools for improving collection, storage and processing of data and information are a first step towards improved water governance.