Home About us Contact
|
Home About us Contact | ||
|
|
||
Water Diversion (water + diversion)
Selected AbstractsGroundwater,surface water interactions in a large semi-arid floodplain: implications for salinity managementHYDROLOGICAL PROCESSES, Issue 16 2005Sébastien Lamontagne Abstract Flow regulation and water diversion for irrigation have considerably impacted the exchange of surface water between the Murray River and its floodplains. However, the way in which river regulation has impacted groundwater,surface water interactions is not completely understood, especially in regards to the salinization and accompanying vegetation dieback currently occurring in many of the floodplains. Groundwater,surface water interactions were studied over a 2 year period in the riparian area of a large floodplain (Hattah,Kulkyne, Victoria) using a combination of piezometric surface monitoring and environmental tracers (Cl,, ,2H, and ,18O). Despite being located in a local and regional groundwater discharge zone, the Murray River is a losing stream under low flow conditions at Hattah,Kulkyne. The discharge zone for local groundwater, regional groundwater and bank recharge is in the floodplain within ,1 km of the river and is probably driven by high rates of transpiration by the riparian Eucalyptus camaldulensis woodland. Environmental tracers data suggest that the origin of groundwater is principally bank recharge in the riparian zone and a combination of diffuse rainfall recharge and localized floodwater recharge elsewhere in the floodplain. Although the Murray River was losing under low flows, bank discharge occurred during some flood recession periods. The way in which the water table responded to changes in river level was a function of the type of stream bank present, with point bars providing a better connection to the alluvial aquifer than the more common clay-lined banks. Understanding the spatial variability in the hydraulic connection with the river channel and in vertical recharge following inundations will be critical to design effective salinity remediation strategies for large semi-arid floodplains. Copyright © 2005 John Wiley & Sons, Ltd. [source] Urban and industrial water use in the Krishna Basin, India,IRRIGATION AND DRAINAGE, Issue 4 2009Daniel J. Van Rooijen Bassin Krishna; utilisation urbaine de l'eau; utilisation industrielle de l'eau; modélisation Abstract Regional urbanization and industrial development require water that may put additional pressure on available water resources and threaten water quality in developing countries. In this study we use a combination of census statistics, case studies, and a simple model of demand growth to assess current and future urban and industrial water demand in the Krishna Basin in southern India. Water use in this "closed" basin is dominated by irrigation (61.9 billion cubic metres (BCM) yr,1) compared to a modest domestic and industrial water use (1.6 and 3.2 BCM yr,1). Total water diversion for non-irrigation purposes is estimated at 7,8% of available surface water in the basin in an average year. Thermal power plants use the majority of water used by industries (86% or 2.7 BCM yr,1), though only 6.8% of this is consumed via evaporation. Simple modelling of urban and industrial growth suggests that non-agricultural water demand will range from 10 to 20 BCM by 2030. This is 14,28% of basin water available surface water for an average year and 17,34% for a year with 75% dependable flow. Although water use in the Krishna Basin will continue to be dominated by agriculture, water stress, and the fraction of water supplies at risk of becoming polluted by urban and industrial activity, will become more severe in urbanized regions in dry years. Copyright © 2008 John Wiley & Sons, Ltd. L'urbanisation régionale et le développement industriel demandent de l'eau, ce qui peut augmenter la pression sur les ressources en eau disponibles dans les pays en développement. Dans cette étude nous utilisons une combinaison de données de recensement, des études de cas et un modèle simple de croissance de la demande pour évaluer la demande en eau urbaine et industrielle actuelle et future dans le bassin Krishna en Inde du sud. Les usages de l'eau dans ce bassin « fermé » sont dominés par l'irrigation (61.9 milliards de m3/an) alors que les usages domestiques et industriels sont modestes (1.6 et 3.2 milliards de m3/an). L'eau utilisée en dehors de l'irrigation est estimée à 7 ,8% de l'eau de surface disponible dans le bassin en année moyenne. Les centrales thermiques utilisent la plus grosse partie de l'eau allouée aux industries (86% ou 2.7 milliards de m3/an) bien que seulement 6.8% de cette quantité soit consommé par évaporation. Une modélisation simple de la croissance urbaine et industrielle suggère que la demande non-agricole d'eau variera de 10 à 20 milliards de m3/an d'ici à 2030. C'est 14,28% de l'eau de surface disponible du bassin en année moyenne et 17,34% de l'écoulement garanti à 75%. Bien que l'utilisation de l'eau dans le bassin Krishna continue à être dominée par l'agriculture, la tension sur l'eau peut devenir plus sévère en année sèche dans les régions urbanisées avec en outre le risque d'une pollution par l'activité urbaine et industrielle. Copyright © 2008 John Wiley & Sons, Ltd. [source] Institutional arrangements for managing the great lakes of the world: Results of a workshop on implementing the watershed approachLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2001Lisa Borre Abstract The conceptual framework for lake management has evolved at an accelerating rate in recent years to include the basic principles of a watershed approach: (i) citizen and stakeholder involvement is important throughout the planning and management process; (ii) the geographic focus for management activities includes the lake and its entire watershed; and (iii) mechanisms need to be in place to promote cooperation among different government jurisdictions and organizations in the watershed. Creating effective institutional arrangements for implementing this watershed approach in lake regions is perhaps the most challenging and important issue facing the world's lakes. LakeNet organized a workshop at the 8th International Conference on the Conservation and Management of Lakes in May 1999. This article is a synthesis of the results of the workshop and the eight case reports prepared by the workshop participants published in this special issue. Seven major threats to lakes were identified: (i) accelerated eutrophication; (ii) invasive species; (iii) toxic contamination; (iv) overfishing; (v) water diversion, (vi) acidification; and (vii) climate change. Institutions and institutional arrangements for addressing these issues and for implementing a watershed approach are just beginning to emerge on lakes around the world. All of the institutions described in the case reports were established or formalized during the 1980s and 1990s. The legal mechanisms creating these institutions range from cooperative agreements among jurisdictions for purposes of policy and planning to national laws and international treaties with full regulatory powers. The knowledge base, political will and financial resources for these activities were very small in comparison with the complexity of the task at hand. [source] Climatic influences and anthropogenic stressors: an integrated framework for streamflow management in Mediterranean-climate California, U.S.A.FRESHWATER BIOLOGY, Issue 2010THEODORE E. GRANTHAM Summary 1. In Mediterranean and other water-stressed climates, water management is critical to the conservation of freshwater ecosystems. To secure and maintain water allocations for the environment, integrated water management approaches are needed that consider ecosystem flow requirements, patterns of human water demands and the temporal and spatial dynamics of water availability. 2. Human settlements in Mediterranean climates have constructed water storage and conveyance projects at a scale and level of complexity far exceeding those in other, less seasonal climates. As a result, multiple ecological stressors associated with natural periods of flooding and drying are compounded by anthropogenic impacts resulting from water infrastructure development. 3. Despite substantial investments in freshwater ecosystem conservation, particularly in California, U.S.A., success has been limited because the scales at which river management and restoration are implemented are often discordant with the temporal and spatial scales at which ecosystem processes operate. Often, there is also strong social and political resistance to restricting water allocation to existing consumptive uses for environmental protection purposes. Furthermore, institutions rarely have the capacity to develop and implement integrated management programmes needed for freshwater ecosystem conservation. 4. We propose an integrated framework for streamflow management that explicitly considers the temporal and spatial dynamics of water supply and needs of both human and natural systems. This approach makes it possible to assess the effects of alternative management strategies to human water security and ecosystem conditions and facilitates integrated decision-making by water management institutions. 5. We illustrate the framework by applying a GIS-based hydrologic model in a Mediterranean-climate watershed in Sonoma County, California, U.S.A. The model is designed to assess the hydrologic impacts of multiple water users distributed throughout a stream network. We analyse the effects of vineyard water management on environmental flows to (i) evaluate streamflow impacts from small storage ponds designed to meet human water demands and reduce summer diversions, (ii) prioritise the placement of storage ponds to meet human water needs while optimising environmental flow benefits and (iii) examine the environmental and social consequences of flow management policies designed to regulate the timing of diversions to protect ecosystem functions. 6. Thematic implications: spatially explicit models that represent anthropogenic stressors (e.g. water diversions) and environmental flow needs are required to address persistent and growing threats to freshwater biodiversity. A coupled human,natural system approach to water management is particularly useful in Mediterranean climates, characterised by severe competition for water resources and high spatial and temporal variability in flow regimes. However, lessons learned from our analyses are applicable to other highly seasonal systems and those that are expected to have increased precipitation variability resulting from climate change. [source] Ecological impacts of dams, water diversions and river management on floodplain wetlands in AustraliaAUSTRAL ECOLOGY, Issue 2 2000R.T. KINGSFORD Abstract Australian floodplain wetlands are sites of high biodiversity that depend on flows from rivers. Darns, diversions and river management have reduced flooding to these wetlands, altering their ecology, and causing the death or poor health of aquatic biota. Four floodplain wetlands (Barmah-Millewa Forest and Moira Marshes, Chowilla floodplain, Macquarie Marshes, Gwydir wetlands) illustrate these effects with successional changes in aquatic vegetation, reduced vegetation health, declining numbers of water-birds and nesting, and declining native fish and invertebrate populations. These effects are likely to be widespread as Australia has at least 446 large dams (>10 m crest height) storing 8.8 × 107 ML (106 L) of water, much of which is diverted upstream of floodplain wetlands. More than 50% of floodplain wetlands on developed rivers may no longer flood. Of all of the river basins in Australia, the Murray-Darling Basin is most affected with dams which can store 103% of annual runoff and 87% of divertible water extracted (1983,84 data). Some floodplain wetlands are now permanent storages. This has changed their biota from one tolerant of a variable flooding regime, to one that withstands permanent flooding. Plans exist to build dams to divert water from many rivers, mainly for irrigation. These plans seldom adequately model subsequent ecological and hydrological impacts to floodplain wetlands. To avoid further loss of wetlands, an improved understanding of the interaction between river flows and floodplain ecology, and investigations into ecological impacts of management practices, is essential. [source] Ecological impacts of dams, water diversions and river management on floodplain wetlands in AustraliaAUSTRAL ECOLOGY, Issue 2 2000R.T. Kingsford Abstract Australian floodplain wetlands are sites of high biodiversity that depend on flows from rivers. Dams, diversions and river management have reduced flooding to these wetlands, altering their ecology, and causing the death or poor health of aquatic biota. Four floodplain wetlands (Barmah-Millewa Forest and Moira Marshes, Chowilla floodplain, Macquarie Marshes, Gwydir wetlands) illustrate these effects with successional changes in aquatic vegetation, reduced vegetation health, declining numbers of water-birds and nesting, and declining native fish and invertebrate populations. These effects are likely to be widespread as Australia has at least 446 large dams (>10 m crest height) storing 8.8 × 107 ML (106 L) of water, much of which is diverted upstream of floodplain wetlands. More than 50% of floodplain wetlands on developed rivers may no longer flood. Of all of the river basins in Australia, the Murray-Darling Basin is most affected with dams which can store 103% of annual runoff and 87% of divertible water extracted (1983,84 data). Some floodplain wetlands are now permanent storages. This has changed their biota from one tolerant of a variable flooding regime, to one that withstands permanent flooding. Plans exist to build dams to divert water from many rivers, mainly for irrigation. These plans seldom adequately model subsequent ecological and hydrological impacts to floodplain wetlands. To avoid further loss of wetlands, an improved understanding of the interaction between river flows and floodplain ecology, and investigations into ecological impacts of management practices, is essential. [source] | |||||||||||||