The Tigris hydropower system operations: the need for an integrated approach

The Tigris hydropower system is analyzed through an integrated operational policy. The operation algorithm is formulated in terms of non-linear programming to maximize energy production while satisfying water demands in the basin. The system is optimized for different cases, and the effects of system modifications in terms of the reservoir volume of Ilisu Dam and the demand constraints are examined. In addition, the state of the Garzan subsystem is analyzed to explore plant utilization when optimizing the entire system operations. The results show the necessity of such an integrated operation plan to supply water demands in the basin.     

基于遥感影像的上荆江典型洲滩植被适宜区分布特征研究

江心洲滩是长江中游河漫滩重要组成部分,厘清洲滩上植被生长适宜区域的分布特征,以及这些区域所应满足的淹没频率临界条件,是生态护滩规划设计和三峡建库后洲滩植被变化预测的重要前提。本文选取上荆江关洲和突起洲分别作为卵石夹沙和沙质型洲滩的典型代表,基于Landsat遥感影像提取了1986—2002年的长时序洲滩淹水范围和植被信息,改进并利用水文特性与影像数据相结合的方法计算了滩面上不同位置的淹没频率和植被频率,分析了二者间的响应规律,确定了植被生长适宜区对应的淹没率条件。研究结果表明：两类洲滩上都存在低、高植被频率区像元相对集中,而中等植被频率区像元较为分散的规律,根据植被频率分布特征,可将滩面区域划分为高频次植被覆盖区、中频次植被覆盖区、过渡区和不适宜区,各区之间的植被频率临界值分别为80%、50%、20%;滩面不同位置的淹没频率是影响植被频率的主导因素,从长时期平均来看两类洲滩上的淹没频率-植被频率响应关系符合统一的Logistic曲线,根据该曲线可确定出各区域的临界淹没条件分别为年均18 d、43 d、92 d。在年均淹没天数大于92 d的区域内,随着淹没天数增加,植被频率迅速减少至10...     

Effects of river regulation on flooding of a riparian red gum forest on the River Murray,Australia

Forests of river red gum (Eucalyptus camaldulensis Dehnh.) occur along the River Murray in Australia. These forests are important for biota, recreation, grazing, and wood products. They occur in a sub-humid to semi-arid environment and require flooding for adequate growth and regeneration. The largest continous area is the Barmah (Victoria) and Millewa (New South Wales) forest near Echuca (Vic.). Information from maps showing the extent of inundation of Barmah Forest for particular floods was related to flow data upstream of the forest, and maps showing the distribution of vegetaton and forest site quality. Vegetation associations were shown to occur in characteristics flood frequency ranges, with red gum being the dominant species on all but the highest and lowest flood frequency sites. In general, higher red gum site quality was associated with higher frequency of flooding. The extent of flooding depended on the magnitude of peak flows in the river. Regulation of the river since the first filling of Hume Dam in 1934 has caused a reduction in the frequency of flows associated with partial flooding and an increase in the occurrence of small summer floods. Areas with a high flood frequency were most affected. It is possible that the forest may change to types associated with reduced duration of inundation in the long-term unless ameliorative action is taken.     

Evaluation of energy expenditure in adult spring Chinook salmon migrating upstream in the Columbia River Basin: an assessment based on sequential proximate analysis

The upstream migration of adult anadromous salmonids in the Columbia River Basin (CRB) has been dramatically altered and fish may be experiencing energetically costly delays at dams. To explore this notion, we estimated the energetic costs of migration and reproduction of Yakima River‐bound spring Chinook salmon Oncorhynchus tshawytscha using a sequential analysis of their proximate composition (i.e., percent water, fat, protein, and ash). Tissues (muscle, viscera, and gonad) were sampled from fish near the start of their migration (Bonneville Dam), at a mid point (Roza Dam, 510 km upstream from Bonneville Dam) and from fresh carcasses on the spawning grounds (about 100 km above Roza Dam). At Bonneville Dam, the energy reserves of these fish were remarkably high, primarily due to the high percentage of fat in the muscle (18–20%; energy content over 11 kJ g^?1). The median travel time for fish from Bonneville to Roza Dam was 27 d and ranged from 18 to 42 d. Fish lost from 6 to 17% of their energy density in muscle, depending on travel time. On average, fish taking a relatively long time for migration between dams used from 5 to 8% more energy from the muscle than faster fish. From the time they passed Bonneville Dam to death, these fish, depending on gender, used 95–99% of their muscle and 73–86% of their visceral lipid stores. Also, both sexes used about 32% of their muscular and very little of their visceral protein stores. However, we were unable to relate energy use and reproductive success to migration history. Our results suggest a possible influence of the CRB hydroelectric system on adult salmonid energetics. Published in 2006 by John Wiley & Sons, Ltd.     

Modelling Evaluation of Dam Removal in the Context of River Ecosystem Restoration

Applications of environmental models may provide imperative information to enable informed decision‐making of river management actions, which are often made in the face of high system complexity and uncertainty. We applied Hydrologic Engineering Centers River Analysis System(HEC‐RAS) and Curvilinear Hydrodynamics Three‐Dimensional (CH3D) models to aid in the decision‐making of the proposed removal of the Masten Dam, a small, ‘run‐of‐the‐river’ dam on the Loxahatchee River, a federally designated ‘Wild and Scenic River’ in south‐east coast of Florida (USA). Anthropogenic alteration of the system has led to changing hydroperiods and salinity regimes in the floodplain. Both models are calibrated against measured data taken at varying temporal and spatial scales. The HEC‐RAS modelling results show that removal of the Masten Dam would lower water levels in the upstream riverine reach, leading to reduced soil moisture or inundation in the floodplain. The CH3D modelling results indicate that dam removal would increase river salinity during the dry season in the tidal reach where salinity compliance for environmental flow regulation is measured. These environmental changes would exert additional stress on freshwater vegetation communities in the floodplain. Given the scarcity of water resources in the region, removal of the Masten Dam would not offer an effective restoration strategy. This study demonstrates not only the need for evaluation of dam removal on a case‐by‐case basis but also the usefulness of environmental models in providing the technical basis for such management decisions. Copyright © 2014 John Wiley & Sons, Ltd.     

Impacts and Implications of Major Changes Caused by the Three Gorges Dam in the Middle Reaches of the Yangtze River, China

The impoundment of the Three Gorges Dam (TGD) has disturbed the hydrological regime downstream and has directly affected the relationship between the Yangtze River and Dongting Lake. To trace the realistic and potential impacts, this paper examined the changes of the channel morphology and sedimentology caused by the TGD through a field survey on the channel cross-sections and then analyzed the impact on lake water level through BP neural networks. The possible impacts on inundation patterns in lake wetlands were studied based on the lake basin DEM. The results indicate that drastic sediment decline and severe channel erosion are putting considerable pressure on the river and lake. Changing river channels are evident in some monitoring cross-sections. Dongting Lake, for the first time, changed from trapping to supplying net sediment to the Yangtze River. During the water storage periods of the TGD, the water level decreased 2.03?m in 2006 and 2.11?m in 2009 at the outlet of the lake, with extreme decreases up to 3.30?m and 3.02?m, respectively. These changes have inevitably induced alterations in the inundation patterns of the lake wetlands, which in turn have disturbed the ecological function of lake wetlands as habitats for both migratory birds and aquatic fish. The serious droughts in Dongting Lake recent years were largely connected with the above changes. Therefore, proper attention should be paid to this occurrence.     

极端条件下堆石坝溃坝风险及应急预案

考虑洪水漫顶条件下的溃决模式,拟定汛限水位、校核洪水位与校核洪水流量、多年平均入库流量的极端组合方式,采用DB-IWHR模型计算堆石坝溃坝洪水过程;利用MIKE 21模拟洪水演进过程,取支流历史最大洪水过程并使其与干支流洪峰遭遇,评估洪水对下游的淹没风险.以涔天河大坝为例,根据库容、堆石材料参数等确定不同入库洪水组合方...     

Modelling inundation patterns and sediment dynamics in the extensive floodplain along the Tonle Sap River

The Tonle Sap River (TSR) serves as a natural medium for the reversal flow between Tonle Sap Lake (TSL) and the Mekong River to sustain productivity and biodiversity in the TSR floodplain and TSL. Understanding the hydrological connectivity and its dynamics in the TSR, including its floodplain, is therefore important to support activities that aim to maintain ecological services in the TSR–TSL system. Thus, the main objective of this study is to examine the hydrological connectivity of the TSR and its floodplain by a modelling approach that integrates inundation patterns and sediment dynamics. The Caesar–Lisflood model was applied to describe inundation, sediment erosion, transport, and deposition in the TSR for the period of 2003–2013. The inundation areas connected to the TSR ranged from 140 to 2,327 km², whereas the isolated inundation areas from the TSR ranged from 0.27 to 504 km². Sediment dynamics showed its influence on inundation patterns and hydrological connectivity and could alter the yearly inundation ratio (defined as a normalized inundation frequency with a value ranging from 0 to 1) up to 0.8. Our approach provides a quantitative way to determine key factors (e.g., total inundation areas, seasonality, and connectivity of inundation patterns) for further investigation of ecological processes in relation to the inundation patterns and sediment dynamics in the TSR and TSL.     

东江水库调节对其下游各级水库淹没的影响

河流梯级开发中，上游有龙头水库时，对下游调节作用较大。如湖南省东江水库系一大型多年调节水库，调节系数为１．３。考虑利用该库空闲库容容纳洪水，减少下泄流量，与区间洪水组合后，下游各梯级设计洪水在洪水标准低于３０年一遇时，其值比原设计小，相应回水降低，淹没损失减少，以东江下游乔口－遥田７个梯级为例，其中乔口，石面担，程江口，永兴，上堡等５梯级减少的淹没损失是原各梯级淹没损失的７８．７２％，经济效益显著     

Environmental impacts of hydroelectric projects on fish resources in China

China has embarked on a programme to vastly expand its hydroelectric generating capacity and this is certain to alter its freshwater and anadromous fish communities. To provide some insight into the direction and consequences of the likely changes, four (>250 000 kW) existing facilities were selected for review. The Gezhouba Dam, on the Changjiang River, commissioned in 1981, is a low-head run of the river facility. The Xinanjiang Dam (1959) is a high-head dam and the Fuchunjiang Dam (1968) is a low-head, run of the river dam, both sited on the Quiantang River. The Danjiangkou Dam (1968) is a high-head dam in the Han River, a tributary of the Changjiang River. Impacts on fish were classified as those caused directly by the structures, those resulting from changes in physical and chemical factors in their environment and those induced through biotic changes in their habitat. Migrations of anadromous and semi-migratory fish were blocked by the Gezhouba Dam, although some species adapted to the new environment by reproducing downstream. Below the Xinanjiang and Danjiangkou dams spawning was delayed 20–60 days by lower water temperatures. Reduced water velocities and less variable discharges caused spawning grounds below the dams to be abandoned. Marked changes in the hydrological regime caused the extinction of Macrura reevesii, a highly valued fish, in the Qiantang River. The fish communities in the Qiantang estuary were affected by the regulated discharge. Freshwater species fell from 96 to 85, whereas marine species increased from 15 to 80. Loss of habitat eliminated torrential habitat species from the areas inundated by Xinanjiang and Danjiangkou Reservoirs; lentic fish replaced lotic species and now dominate the reservoir fish communities. The expanded aquatic habitat was beneficial for fishery production. Catches from the two reservoirs continue to increase 20 years after impoundment, but are supported by extensive artificial propagation and stocking. There is no doubt that, when the expansion of China's hydroelectric facility network is complete, the fish communities in its rivers will be markedly changed.     

丰满大坝整体性研究综述

丰满大坝纵缝上部未设键槽,蓄水前又未灌浆;水平施工缝结合不好,坝体还有各种裂缝,对整体性有一定的影响。丰满大坝于1987年开始进行了全面的加固,整体性得到改善和加强。丰满电厂委托多家进行整体性研究分析,本文介绍各分析成果,并进行综合分析。     

黄河下游滩区淹没损失估算研究

通过典型调查取得滩区社会经济指标和洪水淹没损失指标,计算滩区耕地亩均产值和洪水淹没损失率,并根据预估的不同量级洪水淹没面积,估算不同量级洪水淹没损失,为制定黄河下游滩区补偿标准和执行补偿政策的决策提供依据。     

溪洛渡大坝骨料针片状含量控制研究与生产实践

针片状含量是混凝土骨料质量控制的重要指标,对混凝土的和易性及物理力学性能有较大影响。结合溪洛渡水电站大坝人工骨料加工系统的生产实践,从料源特性、设备选型等方面对影响骨料针片状颗粒产生的机理进行了探讨,提出了剔除预筛料源中部分粒形差的小颗粒和对中、细破碎后的产品进行二次整形处理的措施。采取上述措施后,骨料针片状含量达到小于10%的质量标准,同时骨料筛分效率得到提高。     

Utility of remotely operated underwater vehicle in flood inundation mapping for dam failure: A case study of Lake Tuscaloosa Dam

A remotely operated underwater vehicle (ROV) is a tethered underwater mobile device that can conduct a bathymetric survey cost-efficiently. Assessment of the utility of ROV-based bathymetric surveys in flood inundation mapping remains limited. This study aims to examine the utility of ROV-based bathymetric surveys in high-resolution flood inundation mapping for a hypothetical case study of the Lake Tuscaloosa Dam breach in the state of Alabama, USA. This study conducted the sensitivity test of flood inundation mapping to the river channel depth (ROV-based vs. digital elevation model [DEM]-based) and initial flow condition (e.g., wet vs. dry), via six different simulations of the parallelized diffusion hydrodynamic model (pDHM). This study found that the ROV-based pDHM runs had higher maximum water depths over the flood-inundated areas, ranging from +73% to +166% of the simulated depths of the DEM-based pDHM runs. However, the impact of initial streamflow condition on the maximum depths was limited. This study also found that the pDHM runs with a dry initial flow condition delayed the time to reach the maximum depth after the dam breach by 2 h relative to the pDHM runs with a wet initial streamflow condition. This study suggests that ROV-based bathymetry surveys improve flood inundation mapping by emphasizing the influence of river channel depth, initial streamflow conditions, and bathymetry, thereby bolstering community resilience to a potential human-made hazard such as dam failure.     

越南占化水电站施工总布置设计

占化水电站施工总布置,主要施工工厂集中于一岸布置,减少施工工厂设施投资;选用水库淹没赔偿地作为主要的弃渣场地,减少土地征用;采用拦渣坝措施,既利用冲沟堆渣,又不妨碍冲沟泄水;生产区和生活区合理相隔,体现人性化管理。文章简单介绍占化水电站施工总布置情况。     

小湾水电站水库淹没与移民初议

小湾水电站装机容量４２０万ｋＷ，水库总库容１５１．３亿ｍ３，可进行多年调节，是澜沧江中下游河段梯级开发的关键性工程。虽然有巨大的库容，但淹没损失相对来说还是比较小的。可行性阶段统计，水库淹没耕地３７１２ｈｍ２，占涉及县总耕地面积的１．１４％，迁移农业人口３．２３万人，占涉及县总农业人口的１．５８％。水库淹没处理和移民补偿投资只占工程建设静态投资的１０．７％。水库的建设不会对当地农业生产产生大的影响，移民难度不大；水库的投资不会对工程建设起制约作用。由于水库补偿资金的注入，对促进当地经济的发展和移民的生活改善，将起重要的作用。     

Water, Food, and Energy Security: An Elusive Search for Balance in Central Asia

The development and use of water resources in the Amu Darya Basin remain under debate in the face of increasing population and associated scarcities in water, food, and energy. The upstream riparian, the mountain nation of Tajikistan, wishes to develop its hydropower potential. Three downstream states wish to sustain or increase their economic benefits from water used for irrigation. Growing tensions among the riparian countries on the Vakhsh River, a tributary of Amu Darya, have halted development of Tajikistan’s proposed Rogun Dam. This paper examines the potential for mutually beneficial water development and allocation of water resources to sustain demands for water, food, and energy. Using long-term data on the Basin’s energy potential, water supplies, irrigated land, and crop water demands, this paper analyzes total economic welfare for a future 20-year time horizon. Two water supply scenarios for each of two policy choices are examined. Results show that a constrained economic optimization operation of the Dam has the potential to increase farm income for each riparian country, while producing considerable benefits in hydropower for Tajikistan. Political negotiation among the riparian states and much better data will be needed to discover and implement potential gains indicated by this study.     

The interplay of activists and dam developers: the case of Myanmar’s mega-dams

Scholars investigating activism against large dam developments in Asia usually focus on those campaigning, but not on those the campaigns are aimed at – the dam developers. Yet the developers’ perspective is crucial to comprehensively understand the dynamics of social and environmental activism in South-East Asia as well as its implications for the region’s energy landscape. This article analyzes the interplay of activists and Chinese dam developers in Myanmar via case studies of the Myitsone Dam and the Mong Ton Dam. The research is based on direct scholarly interaction with both activists and dam developers. It presents evidence of change from both sides: activists have professionalized in recent years; and Chinese dam developers now attempt to engage with civil society, albeit with limited success in the two cases studied. Yet, even with these changes, conflict over dam development persists, and the country may soon face severe limitations on development options for improving energy security. The case of Bhutan is also discussed to illustrate the potential of developing Myanmar’s hydropower resources.     

How would the Rogun Dam affect water and energy scarcity in Central Asia?

The construction of the Rogun Dam in the Amu Darya Basin to increase upstream energy generation creates potential trade-offs with existing downstream irrigation, due to the different timing of energy and irrigation water demands. The present analysis, based on a hydro-economic optimization model, shows that cooperative basin-wide maximization of benefits would lead to large increases in upstream hydropower production and only minor changes in downstream irrigation benefits. However, if upstream stations, including Rogun, are managed unilaterally to maximize energy production, hydropower benefits might more than double while irrigation benefits greatly decrease, thereby substantially reducing overall basin benefits.     

Application of WASP model to simulate water pollution control of Duriangkang Dam

Located in Batam City, Duriangkang Dam plays an essential role in providing clean water in the area, also being the first and largest estuary dam in Indonesia. However, with a total effective water volume of 107,000,000 m³, Duriangkang Dam is now heavily polluted because of enormous wastewater loads from both domestic and industrial sources that are directly discharged into the dam. The practice of fish farming has also contributed to its demise. Based on water samples collected during 2016 to 2018, the water condition for Duriangkang Dam is no longer classified as the 2nd class of raw water, based on Indonesian water standards. The present study utilizes the WASP model to evaluate and simulate possible solutions for controlling the Duriangkang Dam water pollution rate. The water quality indicators of dissolved oxygen (DO), total phosphorus (TP) and biochemical oxygen demand (BOD) concentrations are modelled. The calibration and verification results indicate the model exhibited an excellent fitting for DO, BOD and TP concentrations. Under several scenarios, it was determined that the best way to control the pollution rate within the dam is by implementing scenario 8, which include total control of the fish farms and domestic wastewater loads.