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861.
Assessing national sustainable development strategies: Strengthening the links to operational policy
At the Earth Summit in Rio de Janeiro in 1992, it was agreed that all countries should develop a national sustainable develop‐ment strategy (NSDS) as a key component of implementing the goals of Agenda 21. Progress has been limited. Few countries have established a formal strategy, and many of the strategies that exist have been only partially implemented. This article proposes an approach that addresses the need to improve existing strategic planning mechanisms. The approach is based on a periodic assessment of existing systems, to evaluate the extent to which they incorporate NSDS principles, and identify areas to be strengthened. The article describes an assessment methodology, presents examples of its use, and discusses ways in which current approaches to NSDS may be complemented by continual review and improvement of existing planning processes. 相似文献
862.
Basharat A. Pitafi James A. Roumasset 《Journal of the American Water Resources Association》2006,42(6):1441-1450
Abstract: Conserving the watershed can help to preserve ground water recharge. Preventing overuse of available water through pricing reforms can also substantially increase the value of an aquifer. Inasmuch as users are accustomed to low prices, efficiency pricing may be politically infeasible, and watershed conservation may be considered as an alternative. We estimate and compare welfare gains from pricing reform and watershed conservation for a water management district in Oahu that obtains its water supply from the Pearl Harbor aquifer. We find that pricing reform is welfare superior to watershed conservation unless the latter is able to prevent very large recharge losses. Watershed conservation that yields net gains in combination with pricing reform may cause net losses without the pricing reform. If adoption of watershed conservation delays the implementation of pricing reform, the benefits of the latter are significantly reduced. 相似文献
863.
864.
Francisco Olivera Milver Valenzuela R. Srinivasan Janghwoan Choi Hiudae Cho Srikanth Koka Ashish Agrawal 《Journal of the American Water Resources Association》2006,42(2):295-309
This paper presents ArcGIS‐SWAT, a geodata model and geographic information system (GIS) interface for the Soil and Water Assessment Tool (SWAT). The ArcGIS‐SWAT data model is a system of geodatabases that store SWAT geographic, numeric, and text input data and results in an organized fashion. Thus, it is proposed that a single and comprehensive geodatabase be used as the repository of a SWAT simulation. The ArcGIS‐SWAT interface uses programming objects that conform to the Component Object Model (COM) design standard, which facilitate the use of functionality of other Windows‐based applications within ArcGIS‐SWAT. In particular, the use of MS Excel and MATLAB functionality for data analysis and visualization of results is demonstrated. Likewise, it is proposed to conduct hydrologic model integration through the sharing of information with a not‐model‐specific hub data model where information common to different models can be stored and from which it can be retrieved. As an example, it is demonstrated how the Hydrologic Modeling System (HMS) ‐ a computer application for flood analysis ‐ can use information originally developed by ArcGIS‐SWAT for SWAT. The application of ArcGIS‐SWAT to the Seco Creek watershed in Texas is presented. 相似文献
865.
Chao‐Hsien Liaw Yao‐Lung Tsai Mow‐Soung Cheng 《Journal of the American Water Resources Association》2006,42(2):311-322
The Keelung River Basin in northern Taiwan lies immediately upstream of the Taipei metropolitan area. The Shijr area is in the lower basin and is subject to frequent flooding. This work applies micromanagement and source control, including widely distributed infiltration and detention/ retention runoff retarding measures, in the Wudu watershed above Shijr. A method is also developed that combines a genetic algorithm and a rainfall runoff model to optimize the spatial distribution of runoff retarding facilities. Downstream of Wudu in the Shijr area, five dredging schemes are considered. If 10‐year flood flows cannot be confined in the channel, then a levee embankment that corresponds to the respective runoff retarding scheme will be required. The minimum total cost is considered in the rule to select from the regional flood mitigation alternatives. The results of this study reveal that runoff retarding facilities installed in the upper and middle parts of the watershed are most effective in reducing the flood peak. Moreover, as the cost of acquiring land for the levee embankment increases, installing runoff retarding measures in the upper portion of the watershed becomes more economical. 相似文献
866.
ABSTRACT: Flash flooding is the rapid flooding of low lying areas caused by the stormwater of intense rainfall associated with thunderstorms. Flash flooding occurs in many urban areas with relatively flat terrain and can result in severe property damage as well as the loss of lives. In this paper, an integrated one‐dimensional (1‐D) and two‐dimensional (2‐D) hydraulic simulation model has been established to simulate stormwater flooding processes in urban areas. With rainfall input, the model simulates 2‐D overland flow and 1‐D flow in underground stormwater pipes and drainage channels. Drainage channels are treated as special flow paths and arranged along one or more sides of a 2‐D computational grid. By using irregular computation grids, the model simulates unsteady flooding and drying processes over urban areas with complex drainage systems. The model results can provide spatial flood risk information (e.g., water depth, inundation time and flow velocity during flooding). The model was applied to the City of Beaumont, Texas, and validated with the recorded rainfall and runoff data from Tropical Storm Allison with good agreement. 相似文献
867.
Aaron C. Kite‐Powell Anna K. Harding 《Journal of the American Water Resources Association》2006,42(4):975-987
ABSTRACT: Approximately 4.5 million people in the United States who rely on well water are exposed to nitrate‐N concentrations exceeding the 10 mg/l standard. In this study in the Southern Willamette Valley in Oregon we reassessed nitrate‐N in rural wells sampled in 2000–2001, compared nitrate‐N concentrations among geological units, and surveyed residents about their perceptions of well water quality. Nitrate‐N concentrations were again sampled in 2002 and found to have increased significantly from the previous period. With rapid population growth in the area, the potential health risk in drinking well water that exceeds 10 mg/l nitrate‐N warrants continued public education. Nitrate‐N concentrations were found to be higher in the Holocene alluvium of the Willamette River and the Pleistocene sand and gravel post‐Missoula Flood deposits. Researchers conducting future studies may choose to stratify and monitor wells by geologic unit and by other parameters that estimate input of nutrients to the environment. Opinions differed between agricultural landowners and nonagricultural landowners with regard to the impact that agricultural fertilizers may have on water quality. Participants were supportive of a range of regulatory actions that might be used by homeowners or landowners to address ground water contamination. Given that the area is now designated a Groundwater Management Area, understanding local stakeholders’perceptions is critical and strategic and has the potential to help public agencies manage potential conflicts of opinion among stakeholders, build consensus, and help guide the approach to restoring ground water quality. 相似文献
868.
Jing Wu Shaw L. Yu Rui Zou 《Journal of the American Water Resources Association》2006,42(5):1193-1204
ABSTRACT: Watershed management strategies generally involve controlling nonpoint source pollution by implementing various best management practices (BMPs). Currently, stormwater management programs in most states use a performance‐based approach to implement onsite BMPs. This approach fails to link the onsite BMP performance directly to receiving water quality benefits, and it does not take into account the combined treatment effects of all the stormwater management practices within a watershed. To address these issues, this paper proposes a water quality‐based BMP planning approach for effective nonpoint source pollution control at a watershed scale. A coupled modeling system consisting of a watershed model (HSPF) and a receiving water quality model (CE‐QUAL‐W2) was developed to establish the linkage between BMP performance and receiving water quality targets. A Monte Carlo simulation approach was utilized to develop alternative BMP strategies at a watershed level. The developed methodology was applied to the Swift Creek Reservoir watershed in Virginia, and the results show that the proposed approach allows for the development of BMP strategies that lead to full compliance with water quality requirements. 相似文献
869.
Timothy L. Carter Todd C. Rasmussen 《Journal of the American Water Resources Association》2006,42(5):1261-1274
ABSTRACT: Control of stormwater runoff from impervious surfaces is an important national goal because of disruptions to downstream ecosystems, water users, and property owners caused by increased flows and degraded quality. One method for reducing stormwater is the use of vegetated (green) roofs, which efficiently detain and retain stormwater when compared to conventional (black) roofs. A paired green roof‐black roof test plot was constructed at the University of Georgia and monitored between November 2003 and November 2004 for the green roof's effectiveness in reducing stormwater flows. Stormwater mitigation performance was monitored for 31 precipitation events, which ranged in depth from 0.28 to 8.43 cm. Green roof precipitation retention decreased with precipitation depth; ranging from just under 90 percent for small storms (< 2.54 cm) to slightly less than 50 percent for larger storms (> 7.62 cm). Runoff from the green roof was delayed; average runoff lag times increased from 17.0 minutes for the black roof to 34.9 minutes for the green roof, an average increase of 17.9 minutes. Precipitation and runoff data were used to estimate the green roof curve number, CN = 86. This information can be used in hydrologic models for developing stormwater mitigation programs. 相似文献
870.
William Heasom Robert G. Traver Andrea Welker 《Journal of the American Water Resources Association》2006,42(5):1329-1347
ABSTRACT: The goal of this research was to develop a methodology for modeling a bioinfiltration best management practice (BMP) built in a dormitory area on the campus of Villanova University in Pennsylvania. The objectives were to quantify the behavior of the BMP through the different seasons and rainfall events; better understand the physical processes governing the system's behavior; and develop design criteria. The BMP was constructed in 2001 by excavating within an existing traffic island, backfilling with a sand/soil mixture, and planting with salt tolerant grasses and shrubs native to the Atlantic shore. It receives runoff from the asphalt (0.26 hectare) and turf (0.27 hectare) surfaces of the watershed. Monitoring supported by the hydrologic model shows that the facility infiltrates a significant fraction of the annual precipitation, substantially reducing the delivery of nonpoint source pollution and erosive surges downstream. A hydrologic model was developed using HEC‐HMS to represent the site and the BMP using Green‐Ampt and kinematic wave methods. Instruments allow comparison of the modeled and measured water budget parameters. The model, incorporating seasonally variable parameters, predicts the volumes infiltrated and bypassed by the BMP, confirming the applicability of the selected methods for the analysis of bioinfiltration BMPs. 相似文献