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1.
Carroll, Rosemary W.H., Greg Pohll, David McGraw, Chris Garner, Anna Knust, Doug Boyle, Tim Minor, Scott Bassett, and Karl Pohlmann, 2010. Mason Valley Groundwater Model: Linking Surface Water and Groundwater in the Walker River Basin, Nevada. Journal of the American Water Resources Association (JAWRA) 46(3):554-573. DOI: 10.1111/j.1752-1688.2010.00434.x Abstract: An integrated surface water and groundwater model of Mason Valley, Nevada is constructed to replicate the movement of water throughout the different components of the demand side of water resources in the Walker River system. The Mason Valley groundwater surface water model (MVGSM) couples the river/drain network with agricultural demand areas and the groundwater system using MODFLOW, MODFLOW’s streamflow routing package, as well as a surface water linking algorithm developed for the project. The MVGSM is capable of simulating complex feedback mechanisms between the groundwater and surface water system that is not dependent on linearity among the related variables. The spatial scale captures important hydrologic components while the monthly stress periods allow for seasonal evaluation. A simulation spanning an 11-year record shows the methodology is robust under diverse climatic conditions. The basin-wide modeling approach predicts a river system generally gaining during the summer irrigation period but losing during winter months and extended periods of drought. River losses to the groundwater system approach 25% of the river’s annual budget. Reducing diversions to hydrologic response units will increase river flows exiting the model domain, but also has the potential to increase losses from the river to groundwater storage.  相似文献   

2.
Changes in the trends in the material composition of domestic and imported automobiles and the increasing cost of landfilling the non-recyclable portion of automobiles (automobile shredder residue or ASR) pose questions about the future of automobile recycling in the United States. In response to these challenges, new and innovative approaches to automobile recycling are being developed. This paper presents the findings of a recent study to examine the impacts of these changes on the life cycle energy consumption of automobiles and on the quantity of waste that must be disposed of. Given the recycle status quo, trends in material composition and the viability of recycling the non-metallic components of the typical automobile are of secondary importance when compared to the energy consumed during the life of the automobile. The energy savings resulting from small changes in the fuel efficiency of a vehicle overshadow potential energy losses associated with the adoption of new and possibly non-recyclable materials. Under status quo conditions, the life cycle energy consumed by the typical automobile is projected to decrease from 599 million Btus in 1992 to 565 million Btus in 2000. Energy consumed during the manufacture of the typical car will increase from about 120 to 140 million Btus between 1992 and 2000, while energy used during vehicle operation will decrease from 520 to 480 million Btus. This study projects that energy saved at the recycle step will increase from 41 million Btus in 1992 to 55 million Btus in 2000. This study also investigated the energy impacts of several potential changes to the recycle status quo, including the adoption of technologies to retrieve the heat value of ASR by incineration and the recycle of some or all thermoplastics in the typical automobile. The study estimates that under optimistic conditions —i.e., the recycling of all thermoplastics and the incineration with heat recovery of all remaining ASR —about 8 million Btus could be saved per automobile —i.e., an increase from about 55 to 63 million Btus. In the more realistic scenario —i.e., the recycling of easy-to-remove thermoplastic components (bumper covers and dash-boards) —the potential energy savings are about 1 million Btus per vehicle. It is estimated that the annual quantity of ASR in the United States could be reduced from about 5 billion pounds to as little as 1 billion pounds of ash if all ASR is incinerated. Alternatively, ASR quantity could be reduced to about 4 billion pounds if all thermoplastics in automobiles are recycled. However, in the case of recycling only thermoplastic bumper covers and dashboards, the quantity of ASR would be reduced by only 0.2 billion pounds. A significant reduction or increase in the size of the ASR waste stream will not in itself have a large impact on the solid waste stream in the United States.  相似文献   

3.
The water resources of the atolls of the Republic of Maldives are under continual threat from climatic and anthropogenic stresses, including land surface pollution, increasing population, drought, and sea‐level rise (SLR). These threats are particularly acute for groundwater resources due to the small land surface area and low elevation of each island. In this study, the groundwater resources, in terms of freshwater lens thickness, total volume of fresh groundwater, and safe yield are estimated for the 52 most populous islands of the Maldives for current conditions and for the year 2030, with the latter accounting for projected SLR and associated shoreline recession. An algebraic model, designed in previous studies to estimate the lens thickness of atoll islands, is expanded in this study to also estimate volume of groundwater. Results indicate that average current lens thickness, groundwater volume, and per capita safe yield are approximately 4.6 m, 1,300 million liters, and 300 l/day, and that these values will decrease by approximately 10, 11, and 34%, respectively, by the year 2030. Based on results, it is demonstrated that groundwater, in terms of quantity, is a viable source of water for the islands of the Maldives both now and in coming decades, particularly for islands with large surface area and low population. Study results can provide water resource managers and government officials with valuable data for consideration in water security measures.  相似文献   

4.
Water demands in the Aegean Islands have increased steadily over the last decade as a result of a building boom for new homes, hotels, and resorts. The increase in water demand has resulted in the disruption of past sustainable water management practices. At present, most freshwater needs are met through the use of the limited groundwater, desalinated seawater, and freshwater importation. Wastewater reclamation, not used extensively, can serve as an alternative source of water, for a variety of applications now served with desalinated and imported water. Three alternative processes: desalination, importation, and water reclamation are compared with respect to cost, energy requirements and long-term sustainability. Based on the comparisons made, water reclamation and reuse should be components of any long-term water resources management strategy.  相似文献   

5.
ABSTRACT: Typically, infrastructure agencies build massive water projects to serve expanding populations in emerging country cities, but collect and treat only a fraction of the resulting wastewater. This effluent often overwhelms existing sewerage systems and fouls waterways. Cleaning urban waterways requires large investments over long terms and the political will to make and sustain them. This challenge - difficult in advanced countries - becomes daunting with the scarce resources and weak institutions typical of emerging countries. This paper presents a framework to structure such a strategy, and applies it to Madras, India. It consists of three parts: (1) setting a vision through a participatory process; (2) macro investments mainly in wastewater treatment that use least-cost methods; and (3) micro investments in small projects that involve local people and galvanize public support. The macro investment, $350 million for Madras, appears very large, but averages out to $66 per capita, far below the $1,000-$2,000 typical of advanced country cities. Micro projects to be undertaken by Non-Governmental Organizations (NGOs) included an independent wastewater monitoring program, sanitary upgrading of slums along waterways banks, a cattle waste demonstration project, and an industrial pollution survey. Together, a macro/micro strategy promises the funding and political will to achieve a balanced vision of waterways quality.  相似文献   

6.
ABSTRACT. The Bureau of Reclamation was created to implement the Reclamation Act of 1902 and subsequent legislation to conserve and develop the water resources of the western states for maximum efficient use. This has been accomplished by the planning and construction of major multiple use projects which now supply water to approximately eight million acres of land which annually produce 52 million tons of food and fiber with a gross crop value of approximately $2 billion. Fifteen million people are served with municipal and industrial water supplies and hydroelectric power from Bureau projects now returns $160 million annually to the Treasury. Flood control, recreation, and fish and wildlife enhancement are other major benefits. The Bureau of Reclamation is now undertaking a Westwide Survey of water resources and of the needs of the future which is more far-reaching than anything heretofore accomplished. The information accumulated during this ten-year survey will determine whether there is a necessity for consideration of major interbasin transfer of water supply.  相似文献   

7.
A sharp decline in the water level in Jaipur city and its hinterland region in NW India has been observed during the last decades. Such a drop can be correlated with a widening gap between groundwater draft and recharge resulting from poor and erratic rainfall and over-exploitation of groundwater resources. The city has undergone uncontrolled urban expansion complete with a multifold rise in the population, which now stands at more than 3.3 million. Drying up of the surface water bodies has further led to a total dependence on groundwater resources to meet the rising domestic and industrial demand for water. There are about 1,000 bore wells drilled by Governmental agencies and an estimated 11,000 privately owned ones. The water is generally alkaline carbonate–bicarbonate type. We evaluated water quality for the period between 1993 and 2001 and observed notable deterioration that we attribute to inadequate recharge and a change in the potential water-bearing zones from alluvium to granite–gneiss bedrocks, caused by a drop in the water table. In addition, we also attribute the problem of high nitrate in groundwater in densely populated parts of Jaipur city to improper sewage disposal.  相似文献   

8.
Climate Change and River Ecosystems: Protection and Adaptation Options   总被引:3,自引:0,他引:3  
Rivers provide a special suite of goods and services valued highly by the public that are inextricably linked to their flow dynamics and the interaction of flow with the landscape. Yet most rivers are within watersheds that are stressed to some extent by human activities including development, dams, or extractive uses. Climate change will add to and magnify risks that are already present through its potential to alter rainfall, temperature, runoff patterns, and to disrupt biological communities and sever ecological linkages. We provide an overview of the predicted impacts based on published studies to date, discuss both reactive and proactive management responses, and outline six categories of management actions that will contribute substantially to the protection of valuable river assets. To be effective, management must be place-based focusing on local watershed scales that are most relevant to management scales. The first priority should be enhancing environmental monitoring of changes and river responses coupled with the development of local scenario-building exercises that take land use and water use into account. Protection of a greater number of rivers and riparian corridors is essential, as is conjunctive groundwater/surface water management. This will require collaborations among multiple partners in the respective river basins and wise land use planning to minimize additional development in watersheds with valued rivers. Ensuring environmental flows by purchasing or leasing water rights and/or altering reservoir release patterns will be needed for many rivers. Implementing restoration projects proactively can be used to protect existing resources so that expensive reactive restoration to repair damage associated with a changing climate is minimized. Special attention should be given to diversifying and replicating habitats of special importance and to monitoring populations at high risk or of special value so that management interventions can occur if the risks to habitats or species increase significantly over time.  相似文献   

9.
以新疆喀什噶尔河流域克孜河卡拉贝利水利枢纽工程为例,采用水均衡模型计算方法,从工程建成后区域荒漠河岸林草耗水量变化、荒漠河岸林草区地下水位变化情况、工程建成后洪水过程变化等方面分析工程建设对工程影响区荒漠河岸林草的影响。评价结果显示,工程建成后,与现状相比荒漠河岸林草植被的耗水量有所增加,区域平均地下水埋深仍能维持现状,在河岸林草生长和繁殖的6-9月,区域地下水位较现状略有上升,可满足大部分荒漠河岸林草植被的正常生长需求,水库对5年一遇标准以下洪水不调蓄,不会对荒漠河岸林草的繁衍存活产生明显不利影响。  相似文献   

10.
ABSTRACT: Outdoor recreation is a major, growing use of water resources in the United States. The economic effects of expenditures by visitors to three recreational river sites on local economies surrounding the sites were estimated using an input-output model (IMPL.AN). Expenditure data were from the Public Area Recreation Visitors Study (PARVS). Results indicate that visitor spending stimulates a considerable amount of economic activity and growth in local economies. Economic effects include increases in total gross output ranging from $2.6 million to $13.4 million, increases in total income ranging from $1.2 million to $5.6 million, and increases in employment ranging from 60 to 292 jobs.  相似文献   

11.
宁波为典型的丰水型缺水城市,调蓄开发地下水库,是丰水型缺水城市或干旱地区减少地表和地下径流弃水,提高水资源利用率,缓和水资源供需矛盾的重要管理方案.  相似文献   

12.
On the face of it, the 1990s have marked the transformation of the UK's waste management policy. A commitment to waste minimisation and recycling, within the terms of the internationally accepted waste hierarchy, have replaced an almost complacent defence of landfill. However, aside from the dramatic transformation of the vocabulary, the reality of local authority waste disposal has, with a few notable exceptions, been characterised more by continuity than revolution. This article suggests that the modesty of local authority recycling is best explained through an appreciation of what can be described as recycling practice. Recycling in the UK has taken a distinctive form comprising: environmentalism, entrepreneurialism and policy advocacy. The components of this practice explain both the successes and failures of local authority recycling. Despite its oppositional roots, the Conservative Government found 'recycling practice' conducive to their reliance upon a mix of aspirational targets and market-based instruments (MBIs). Advice circulated as guidance to local authorities emphasised viability as the principal criterion of scheme assessment and in such a way sustained the limited scale and ambitions of recycling practice.  相似文献   

13.
Assessment of river 'health' using biological methods, particularly those based on macro-invertebrates, is now commonplace in most developed countries. However, this is not the case in most developing countries, where physical and chemical methods are used to assess water quality, with very little use of biological assessment methods. This paper reports on a project that aimed to assess the possible introduction of biological assessment of river condition using the Australian River Assessment System (AUSRIVAS) into Indonesia. The paper addresses three components of the project: (1) science--does the bioassessment method work in this tropical region? (2) resources--are they adequate and if not what additional resources are needed? (3) politics--what needs to be done to convince the agencies (both central and provincial) to take up such a new philosophy and approach? A pilot study was run in the upper Brantas River, East Java. A total of 66 reference sites and 15 test sites were sampled and the macro-invertebrates collected were identified to family level. A rigorous quality-control protocol was introduced to ensure the data were reliable and reproducible. The macro-invertebrate data were used to develop a predictive model of the AUSRIVAS type for the upper Brantas River, and the model was then used to assess the 'health' of sites that were presumed to be damaged in this section of the river. A number of difficulties were experienced during the study, including: locating reference sites sufficiently unmodified by humans; lack of skills to identify animals collected; and a paucity of facilities required for aquatic macro-invertebrate identification (e.g. identification keys and good quality binocular microscopes). For resources, the major constraint to the introduction of a bioassessment capability in Indonesia is the lack of personnel trained in the bioassessment techniques. An 'on-the-job' training approach was adopted, largely because of the specialist nature of this work. Six Indonesians were trained and will now become the 'trainers' of further Indonesian scientists (we have called this process 'training-the-trainers'). For politics, it was hoped that the AUSRIVAS method would be suitable for introduction into the Indonesian national Clean River Program. A strategy was developed and implemented to ensure the method and its outputs were accepted technically by the Indonesian scientific community, and also by the resource managers and relevant government officials. Experience shows that if the latter do not see how the bioassessment information will be used for management purposes they will not accept the method even if it is scientifically sound.  相似文献   

14.
ABSTRACT: The economic feasibility of a large scale dual purpose (desalting water and power production) facility were evaluated. Although a site in the Tularosa basin of southern New Mexico was chosen as a case study for this analysis, it is believed that the approach and consequential results would be applicable to alternative sites in the Southwest. The basic project evaluated included: a) a ground water well field; b) a dual purpose, nuclear, desalination plant; c) a mineral recovery plant; and d) a reservoir for recreation and irrigation storage. Principle project outputs included electrical power, minerals, recreation, and water for either irrigated agricultural production or export to an adjoining river basin. Two alternative project designs were developed for detailed analysis. The first alternative encompassed all major project components. The results, in discounted net values used to assess the feasibility of the project, were essentially negative; that is, values were less than zero for full scale development. The net benefits ranged from $-986.57 million at a 5 percent discount rate, to $-1,137.528 million at a discount rate of 10 percent. In the second alternative, exportation of the desalted water from the Tularosa basin to two adjacent rivers was analyzed with somewhat better net benefits, ranging from $-382,527 million to $-478,612 million at the 5 and 10 percent discount rates.  相似文献   

15.
This study presents the results of a comparative life cycle assessment (LCA) on the energy requirements and greenhouse gas (GHG) emission implications of recycling construction and demolition (C&D) rubble and container glass in Cape Town, South Africa. Cape Town is a medium sized city in a developing country with a growing population and a rising middle class, two factors that are resulting in increased generation of solid waste. The City is constrained in terms of landfill space and competing demands for municipal resources.The LCA assessment was based on locally gathered data, supplemented with ecoinvent life cycle inventory data modified to the local context. The results indicated that recycling container glass instead of landfilling can achieve an energy savings of 27% and a GHG emissions savings of 37%, with a net savings still being achieved even if collection practices are varied. The C&D waste results, however, showed net savings only for certain recycling strategies. Recycling C&D waste can avoid up to 90% of the energy and GHG emissions of landfilling when processed and reused onsite but, due to great dependence on haulage distances, a net reduction of energy use and GHG emissions could not be confidently discerned for offsite recycling. It was also found that recycling glass achieves significantly greater savings of energy and emissions than recycling an equivalent mass of C&D waste.The study demonstrated that LCA provides an important tool to inform decisions on supporting recycling activities where resources are limited. It also confirmed other researchers’ observations that strict adherence to the waste management hierarchy will not always result in the best environmental outcome, and that more nuanced analysis is required. The study found that the desirability of recycling from an energy and climate perspective cannot be predicted on the basis of whether such recycling conserves a non-renewable material. However, recycling that replaces a virgin product from an energy-intensive production process appears to be more robustly beneficial than recycling that replaces a product with little embodied energy. Particular caution is needed when applying the waste management hierarchy to the latter situations.  相似文献   

16.
超滤膜技术在21世纪水处理领域的展望   总被引:2,自引:0,他引:2  
本文介绍了半死端超滤膜技术的典型设备和运行工艺及其优化。并且介绍了在世界范围内此项技术在地下水,地表水等常规水源处理以及海水和污水回用等非常规水源方面的应用。  相似文献   

17.
ABSTRACT: Most of us are aware, or feel we are aware, of the impacts of major water resources projects on our lives. “Dam-lovers” note the life-saving flood-risk reduction and recreational benefits of a proposed reservoir, while “dam-haters” bemoan the future drowning out of the wildlife habitat of its river valley, and the recreational disbenefits to stream (as opposed to lake) fishermen. Water supply projects can often be given such a revered status, assuming the “obvious” tenet that water, air, food, and shelter are basic requirements of decent living, that the economic viability of the project may not even be assessed. Water resources planners are supposed to impartially weigh the environmental and economic benefits, and especially now, the energy implications of all proposed water projects, but many times the partial views of political or public advocates may be hard to ignore. The assumptions used in the planning of four recent water projects in the Province of Alberta will be presented and some revisions suggested which materially affect their Benefit/Cost ratios. In one project that is still in the public hearing stage, the economic analysis will be revealed, indicating that the original B/C ratio of about 1.6:1 might be more realistically placed at 0.6:1. In another project just completed, the apparent lack of an economic or energy analysis that has resulted in a perpetual and unnecessary energy load on the province, will be described.  相似文献   

18.
在分析废旧塑料再生利用工艺过程的基础上,确定了废塑料综合利用工艺的产污节点,并通过物流平衡和水平衡计算,得出了总的产排污量,为环境保护措施提供重要依据,以实现保护环境和资源合理再生利用。  相似文献   

19.
The development of Australia's North-West Shelf gasfield is the largest single private venture yet undertaken in Australia, with expenditure of around A$3000 million. Gas will be exported (primarily to Japan), and there will be local sales, at present confined to the state of Western Australia. Annual revenue is estimated to be A$743 million (in 1977 prices) over the life of the project, with annual tax and royalties rising to A$330 million once loans are repaid. The net effect on Australia's balance of payments is positive in most years. The project's apparent feasibility has provided an impetus to further offshore exploration in the West, with A$400 million now committed.  相似文献   

20.
黑河是我国第二大内陆河,流域内湖泊、沼泽遍布,湿地资源丰富。多年来人们对黑河环境的重要性认识不足,导致植被退化、水位下降、土地盐渍化,影响湿地资源的永续利用,制约当地经济社会可持续发展。鉴于此,建立了黑河湿地国家级自然保护区,实施湿地保护与恢复和污染治理工程,增强退耕还林(草)、退地还湿、防沙治沙力度,探索和运用生态补偿机制。  相似文献   

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