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451.
Recent Changes in Stream Flashiness and Flooding,and Effects of Flood Management in North Carolina and Virginia 下载免费PDF全文
Beatriz Mogollón Emmanuel A. Frimpong Andrew B. Hoegh Paul L. Angermeier 《Journal of the American Water Resources Association》2016,52(3):561-577
The southeastern United States has undergone anthropogenic changes in landscape structure, with the potential to increase (e.g., urbanization) and decrease (e.g., reservoir construction) stream flashiness and flooding. Assessment of the outcome of such change can provide insight into the efficacy of current strategies and policies to manage water resources. We (1) examined trends in precipitation, floods, and stream flashiness and (2) assessed the relative influence of land cover and flow‐regulating features (e.g., best management practices and artificial water bodies) on stream flashiness from 1991 to 2013. We found mean annual precipitation decreased, which coincided with decreasing trends in floods. In contrast, stream flashiness, overall, showed an increasing trend during the period of study. However, upon closer examination, 20 watersheds showed stable stream flashiness, whereas 5 increased and 6 decreased in flashiness. Urban watersheds were among those that increased or decreased in flashiness. Watersheds that increased in stream flashiness gained more urban cover, lost more forested cover and had fewer best management practices installed than urban watersheds that decreased in stream flashiness. We found best management practices are more effective than artificial water bodies in regulating flashy floods. Flashiness index is a valuable and straightforward metric to characterize changes in streamflow and help to assess the efficacy of management interventions. 相似文献
452.
Bison and cattle grazing management,bare ground coverage,and links to suspended sediment concentrations in grassland streams 下载免费PDF全文
Bartosz P. Grudzinski Melinda D. Daniels Kyle Anibas David Spencer 《Journal of the American Water Resources Association》2016,52(1):16-30
This study quantified the impact of bison and cattle grazing management practices on bare ground coverage at the watershed, riparian, and forested riparian scales within the Flint Hills ecoregion in Kansas. We tested for correlations between bare ground coverage and fluvial suspended sediment concentrations during base‐flow and storm‐flow events. We used remotely sensed imagery combined with field surveys to classify ground cover and quantify the presence of bare ground. Base‐flow water samples were collected bi‐monthly during rain‐free periods and 24 h following precipitation events. Storm‐flow water samples were collected on the rising limb of the hydrograph, using single‐stage automatic samplers. Ungrazed treatments contained the lowest coverage of bare ground at the watershed, riparian, and forested riparian scales. Bison treatments contained the highest coverage of bare ground at the watershed scale, while high‐density cattle treatments contained the highest coverage of bare ground at the riparian and forested riparian scales. In bison and cattle‐grazed treatments, a majority of bare ground was located near fence lines, watershed boundaries, and third‐ and fourth‐order stream segments. Inorganic sediment concentrations at base flow were best predicted by riparian bare ground coverage, while storm‐flow sediment concentrations were best predicted by watershed scale bare ground coverage. 相似文献
453.
Benchmarking Optical/Thermal Satellite Imagery for Estimating Evapotranspiration and Soil Moisture in Decision Support Tools 下载免费PDF全文
Jan M.H. Hendrickx Richard G. Allen Al Brower Aaron R. Byrd Sung‐ho Hong Fred L. Ogden Nawa Raj Pradhan Clarence W. Robison David Toll Ricardo Trezza Todd G. Umstot John L. Wilson 《Journal of the American Water Resources Association》2016,52(1):89-119
Generally, one expects evapotranspiration (ET) maps derived from optical/thermal Landsat and MODIS satellite imagery to improve decision support tools and lead to superior decisions regarding water resources management. However, there is lack of supportive evidence to accept or reject this expectation. We “benchmark” three existing hydrologic decision support tools with the following benchmarks: annual ET for the ET Toolbox developed by the United States Bureau of Reclamation, predicted rainfall‐runoff hydrographs for the Gridded Surface/Subsurface Hydrologic Analysis model developed by the U.S. Army Corps of Engineers, and the average annual groundwater recharge for the Distributed Parameter Watershed Model used by Daniel B. Stephens & Associates. The conclusion of this benchmark study is that the use of NASA/USGS optical/thermal satellite imagery can considerably improve hydrologic decision support tools compared to their traditional implementations. The benefits of improved decision making, resulting from more accurate results of hydrologic support systems using optical/thermal satellite imagery, should substantially exceed the costs for acquiring such imagery and implementing the remote sensing algorithms. In fact, the value of reduced error in estimating average annual groundwater recharge in the San Gabriel Mountains, California alone, in terms of value of water, may be as large as $1 billion, more than sufficient to pay for one new Landsat satellite. 相似文献
454.
Emerging Tools for Continuous Nutrient Monitoring Networks: Sensors Advancing Science and Water Resources Protection 下载免费PDF全文
Brian A. Pellerin Beth A. Stauffer Dwane A. Young Daniel J. Sullivan Suzanne B. Bricker Mark R. Walbridge Gerard A. Clyde Jr. Denice M. Shaw 《Journal of the American Water Resources Association》2016,52(4):993-1008
Sensors and enabling technologies are becoming increasingly important tools for water quality monitoring and associated water resource management decisions. In particular, nutrient sensors are of interest because of the well‐known adverse effects of nutrient enrichment on coastal hypoxia, harmful algal blooms, and impacts to human health. Accurate and timely information on nutrient concentrations and loads is integral to strategies designed to minimize risk to humans and manage the underlying drivers of water quality impairment. Using nitrate sensors as the primary example, we highlight the types of applications in freshwater and coastal environments that are likely to benefit from continuous, real‐time nutrient data. The concurrent emergence of new tools to integrate, manage, and share large datasets is critical to the successful use of nutrient sensors and has made it possible for the field of continuous monitoring to rapidly move forward. We highlight several near‐term opportunities for federal agencies, as well as the broader scientific and management community, that will help accelerate sensor development, build and leverage sites within a national network, and develop open data standards and data management protocols that are key to realizing the benefits of a large‐scale, integrated monitoring network. Investing in these opportunities will provide new information to guide management and policies designed to protect and restore our nation's water resources. 相似文献
455.
Coupling of the Water Cycle with Patterns of Urban Growth in the Baltimore Metropolitan Region,United States 下载免费PDF全文
Aditi S. Bhaskar Claire Jantz Claire Welty Scott A. Drzyzga Andrew J. Miller 《Journal of the American Water Resources Association》2016,52(6):1509-1523
Regional municipal water plans typically do not recognize complex coupling patterns or that increased withdrawals in one location can result in changes in water availability in others. We investigated the interaction between urban growth and water availability in the Baltimore metropolitan region where urban growth has occurred beyond the reaches of municipal water systems into areas that rely on wells in low‐productivity Piedmont aquifers. We used the urban growth model SLEUTH and the hydrologic model ParFlow.CLM to evaluate this interaction with urban growth scenarios in 2007 and 2030. We found decreasing groundwater availability outside of the municipal water service area. Within the municipal service area we found zones of increasing storage resulting from increased urban growth, where reduced vegetation cover dominated the effect of urbanization on the hydrologic cycle. We also found areas of decreasing storage, where expanding impervious surfaces played a larger role. Although the magnitude of urban growth and change in water availability for the simulation period were generally small, there was considerable spatial heterogeneity of changes in subsurface storage. This suggests that there are locally concentrated areas of groundwater sensitivity to urban growth where water shortages could occur or where drying up of headwater streams would be more likely. The simulation approach presented here could be used to identify early warning indicators of future risk. 相似文献
456.
Kandace Kea Randel Dymond Warren Campbell 《Journal of the American Water Resources Association》2016,52(6):1433-1449
Several factors, such as municipality location and population, are thought to influence trends among stormwater utilities (SWUs); however, no analysis of the relationship between these factors and SWU characteristics has been performed. This article corroborates hypothesized relationships and identifies trends and patterns in the establishment, funding mechanism, and magnitude of SWUs by analyzing location, population density, home value, and year of establishment for a comprehensive national SWU database with data for 1,490 SWUs. The equivalent residential unit (ERU), a SWU that charges based on impervious area, was the most prevalent funding mechanism in all National Oceanic and Atmospheric Administration Climate Regions of the United States except the West and West‐North‐Central. The ERU was also found in larger cities with high population densities, whereas the Flat Fee, a SWU that charges a single rate for all properties, was found in smaller towns. Higher home values were correlated with higher monthly fees for 28% of the municipalities analyzed. The residential equivalence factor, a SWU that charges based on runoff produced, was popular in municipalities with higher home values, whereas the Flat Fee was popular in municipalities with lower home values. The number of SWUs established increased with Phase I municipal separate stormwater and sewer system (MS4) permit and Phase II small MS4 permit deadlines. Summary tables provide guidance to aid municipalities considering a SWU. 相似文献
457.
Institutional Constraints on Cost‐Effective Water Management: Selenium Contamination in Colorado's Lower Arkansas River Valley 下载免费PDF全文
Misti D. Sharp Dana L.K. Hoag Ryan T. Bailey Erica C. Romero Timothy K. Gates 《Journal of the American Water Resources Association》2016,52(6):1420-1432
Ground and surface water selenium (Se) contamination is problematic throughout the world, leading to harmful impacts on aquatic life, wildlife, livestock, and humans. A groundwater reactive transport model was applied to a regional‐scale irrigated groundwater system in the Lower Arkansas River Basin in southeastern Colorado to identify management practices that remediate Se contamination. The system has levels of surface water and groundwater Se concentrations exceeding the respective chronic standard and guidelines. We evaluate potential solutions by combining the transport model with an assessment of the cost to employ those practices. We use a framework common in economics and engineering fields alike, the Pareto frontier, to show the impact of four different best management practices on the tradeoffs between Se and cost objectives. We then extend that analysis to include institutional constraints that affect the economic feasibility associated with each practice. Results indicate that although water‐reducing strategies have the greatest impact on Se, they are the hardest for farmers to implement given constraints common to western water rights institutions. Therefore, our analysis shows that estimating economic and environmental tradeoffs, as is typically done with a Pareto frontier, will not provide an accurate picture of choices available to farmers where institutional constraints should also be considered. 相似文献
458.
Since the 1990s, the local level of governance has become increasingly important in addressing the challenge of sustainable development. In this article, we compare two approaches that seek to address sustainability locally, namely Local Agenda 21 and transition management. Discussing both approaches along six dimensions (history, aim, kind of change, governance understanding, process methodologies, and actors), we formulate general insights into the governance of sustainability in cities, towns, and neighbourhoods. This dialogue illustrates two related modes of thinking about sustainability governance. We touch upon the importance of an integrated perspective on sustainability transitions through which sustainability is made meaningful locally in collaborative processes. We suggest that the explicit orientation towards radical change is a precondition for governing sustainability in a way that addresses the root causes of societal challenges. Governing sustainability should address the tensions between aiming for radical change and working with status quo-oriented actors and governing settings. We conclude that governing sustainability should be about finding creative ways for opening spaces for participation, change, and experimentation, that is, for creating alternative ideas, practices, and social relations. These spaces for innovation encourage a reflexive stance on ways of working and one's own roles and attitudes, thereby preparing a fertile terrain for actors to engage in change from different perspectives. 相似文献
459.
Bruce K. Ferguson 《Journal of the American Water Resources Association》2016,52(5):1238-1250
Urban stormwater practices are individually diverse, but they are components of an overall urban watershed system. This study proposes a conceptual model of that system, including its component spatial areas, their arrangement along the flow route, and their associations with urban land uses and values. The model defines three spatial areas along the flow route which have evolved over time into their present forms: (1) the source area, which is arranged and furnished primarily or entirely for human use, accommodation, and comfort; (2) the perimeter area, where specialized stormwater facilities carry away source‐area runoff or buffer downstream areas from its impacts; and (3) the downstream area, which receives the discharges from the perimeter or directly from the source area. Each area presents a specific combination of stormwater features and human interactions, and excludes others. Considering stormwater flows and functions in the context of physical urban spaces brings into view the spaces’ urban structures and interacting agendas. This model allows practitioners to navigate conceptually through the system, and to focus appropriate objectives and structures on each project site. 相似文献
460.
Nazanin Shabani 《International Journal of Green Energy》2016,13(7):631-641
Mathematical programming models have been used to optimize the design and management of forest bioenergy supply chains. A deterministic mathematical model is beneficial for making optimum decisions; however, its applicability to real-world problems may be limited because it does not capture all the complexities, including uncertainties in the parameters, in the supply chain. In this paper, a combination of Monte Carlo Simulation and optimization model is used to evaluate the impact of uncertainty in biomass quality, availability and cost, and electricity prices on the supply chain of a forest biomass power plant. The optimization model is a deterministic mixed integer non-linear model with monthly time steps over a 1-year planning horizon. Variability in biomass quality, i.e. moisture content (MC) and higher heating value (HHV), based on the historical data of a real case study is studied in detail and fitted probability distributions are used in the model, while for electricity prices different scenarios are considered. The results show that the impact of variability in the MC on profit is higher than that of uncertainty in HHV. It is observed that the annual profit ranges between $13.3 million and $17.9 million in the presence of all possible uncertainties while its average is $15.5 million. Uncertainty in biomass availability and cost and electricity price results in the risks of having annual profit of less than $14 million and low monthly storage levels. 相似文献