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Hydrological Connectivity Between Headwater Streams and Downstream Waters: How Science Can Inform Policy1 总被引:1,自引:0,他引:1
Tracie‐Lynn Nadeau Mark Cable Rains 《Journal of the American Water Resources Association》2007,43(1):118-133
Abstract: In January 2001, the U.S. Supreme Court ruled that the U.S. Army Corps of Engineers exceeded its statutory authority by asserting Clean Water Act (CWA) jurisdiction over non‐navigable, isolated, intrastate waters based solely on their use by migratory birds. The Supreme Court’s majority opinion addressed broader issues of CWA jurisdiction by implying that the CWA intended some “connection” to navigability and that isolated waters need a “significant nexus” to navigable waters to be jurisdictional. Subsequent to this decision (SWANCC), there have been many lawsuits challenging CWA jurisdiction, many of which are focused on headwater, intermittent, and ephemeral streams. To inform the legal and policy debate surrounding this issue, we present information on the geographic distribution of headwater streams and intermittent and ephemeral streams throughout the U.S., summarize major findings from the scientific literature in considering hydrological connectivity between headwater streams and downstream waters, and relate the scientific information presented to policy issues surrounding the scope of waters protected under the CWA. Headwater streams comprise approximately 53% (2,900,000 km) of the total stream length in the U.S., excluding Alaska, and intermittent and ephemeral streams comprise approximately 59% (3,200,000 km) of the total stream length and approximately 50% (1,460,000 km) of the headwater stream length in the U.S., excluding Alaska. Hillslopes, headwater streams, and downstream waters are best described as individual elements of integrated hydrological systems. Hydrological connectivity allows for the exchange of mass, momentum, energy, and organisms longitudinally, laterally, vertically, and temporally between headwater streams and downstream waters. Via hydrological connectivity, headwater, intermittent and ephemeral streams cumulatively contribute to the functional integrity of downstream waters; hydrologically and ecologically, they are a part of the tributary system. As this debate continues, scientific input from multiple fields will be important for policymaking at the federal, state, and local levels and to inform water resource management regardless of the level at which those decisions are being made. Strengthening the interface between science, policy, and public participation is critical if we are going to achieve effective water resource management. 相似文献
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The Canadian Forest Fire Danger Rating System (CFFDRS) is used daily across Canada for evaluating forest fire danger. Fuel-type information is one of the inputs required by the models used in the CFFDRS. In this project, three fuel-type maps with a 25 m resolution were produced for a pilot study area located in Alberta using land cover only; land cover and biomass; and, land cover, biomass and leaf area index data derived from satellite imagery. The relationships between inputs and fuel types were determined mainly by the opinions of forest fire scientists and incorporated into a computer program using fuzzy set methodology. Not all the CFFDRS fuel types could be distinguished using these inputs; three of the coniferous types had to be grouped into one common fuel type. Overall accuracy was between 74 and 83% based on ground-truth comparisons. The most accurate map resulted from land cover and biomass data. Detailed accuracy assessment indicated that the overall accuracy increased up to 86% if ambiguous fuel type identification was considered. No combination of inputs was able to define a fuel type with absolute certainty, which is a reflection of differing expert opinions and the small number of inputs used to produce the maps. 相似文献
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Ken M. Fritz Elisabeth Hagenbuch Ellen D'Amico Molly Reif Parker J. Wigington Jr. Scott G. Leibowitz Randy L. Comeleo Joseph L. Ebersole Tracie‐Lynn Nadeau 《Journal of the American Water Resources Association》2013,49(4):867-882
Supreme Court cases have questioned if jurisdiction under the Clean Water Act extends to water bodies such as streams without year‐round flow. Headwater streams are central to this issue because many periodically dry, and because little is known about their influence on navigable waters. An accurate account of the extent and flow permanence of headwater streams is critical to estimating downstream contributions. We compared the extent and permanence of headwater streams from two field surveys with values from databases and maps. The first used data from 29 headwater streams in nine U.S. forests, whereas the second had data from 178 headwater streams in Oregon. Synthetic networks developed from the nine‐forest survey indicated that 33 to 93% of the channel lacked year‐round flow. Seven of the nine forests were predicted to have >200% more channel length than portrayed in the high‐resolution National Hydrography Dataset (NHD). The NHD and topographic map classifications of permanence agreed with ~50% of the field determinations across ~300 headwater sites. Classification agreement with the field determinations generally increased with increasing resolution. However, the flow classification on soil maps only agreed with ~30% of the field determination despite depicting greater channel extent than other maps. Maps that include streams regardless of permanence and size will aid regulatory decisions and are fundamental to improving water quality monitoring and models. 相似文献
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Estimation of urban sensible heat flux using a dense wireless network of observations 总被引:1,自引:0,他引:1
Daniel F. Nadeau W. Brutsaert M. B. Parlange E. Bou-Zeid G. Barrenetxea O. Couach M.-O. Boldi J. S. Selker M. Vetterli 《Environmental Fluid Mechanics》2009,9(6):635-653
The determination of the sensible heat flux over urban terrain is challenging due to irregular surface geometry and surface
types. To address this, in 2006–07, a major field campaign (LUCE) took place at the école Polytechnique Fédérale de Lausanne
campus, a moderately occupied urban site. A distributed network of 92 wireless weather stations was combined with routine
atmospheric profiling, offering high temporal and spatial resolution meteorological measurements. The objective of this study
is to estimate the sensible heat flux over the built environment under convective conditions. Calculations were based on Monin–Obukhov
similarity for temperature in the surface layer. The results illustrate a good agreement between the sensible heat flux inferred
from the thermal roughness length approach and independent calibrated measurements from a scintillometer located inside the
urban canopy. It also shows that using only one well-selected station can provide a good estimate of the sensible heat flux
over the campus for convective conditions. Overall, this study illustrates how an extensive network of meteorological measurements
can be a useful tool to estimate the sensible heat flux in complex urban environments. 相似文献
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John M Peckenham James A Nadeau Aria Amirbahman Richard S Behr 《Waste management & research》2008,26(2):163-172
Concerns over elevated nitrate (NO3-) levels found in groundwater near former biosolid stockpiling locations resulted in the Maine Department of Environmental Protection (MDEP) imposing stricter regulations governing the stockpiling of biosolids in October 2002. The goals of this study were to measure the amount and speciation of nitrogen (N) and trace metals leaving stockpiled biosolids and travelling through the soil column. The biosolids were placed on plastic-lined cells to collect all leachate. Ammonium (NH4+), ranging from 2000 to 4900 mg L(-1), was the dominant N species (90% of total N) in the leachate from the Class B lime-stabilized biosolids in the lined cell experiment. Nitrate (NO3-) and nitrite (NO2-) concentrations were negligible, remaining below 0.25 and 0.1 mg L(-1), respectively. Dissolved organic carbon (DOC) concentrations as high as 8900 mg L(-1) and chemical oxygen demand (COD) as high as 37 000 mg L(-1) were measured in the leachate leaving the lined cell. Fifteen zero-tension pan lysimeters (ZTP-lysimeter) were installed in a 90 m2 plot at depth intervals of 30, 60, and 100 cm. Leachate passing through the soil column underlying the biosolids stockpile was collected in the ZTP-lysimeters. The average ZTP-lysimeter NH4+ concentrations ranged from 1400 mg L(-1) at 60 cm depth to 145 mg L(-1) at 90 cm depth. The average ZTP-lysimeter DOC concentrations ranged from 2000 mg L(-1) at 60 cm to 525 mg L(-1) at 90 cm. Trace metal determinations of the leachate collected from the lined cell and ZTP-lysimeters showed arsenic loading rates exceeded the state limits of 0.5 kg ha(-1) year(-1) by an order of magnitude. Arsenic concentrations were in excess of several thousand milligrams per litre in the lined-cell leachate and several hundred milligrams per litre in the ZTP-lysimeters as deep as 90 cm under the biosolid stockpile. Phosphorus, iron and manganese in excess of several thousand milligrams per litre were observed in both the lined-cell leachate and ZTP-lysimeters. Significant concentrations of other trace metals were found at depth in the zero-tension ZTP-lysimeter plot. Trace metals were largely mobilized by the DOC from the biosolids and due to the presence of anaerobic environment, especially in the underlying soil. 相似文献
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Adel Badri Sylvie Nadeau André Gbodossou 《Journal of Loss Prevention in the Process Industries》2013,26(6):1145-1158
The mining industry worldwide is currently experiencing an economic boom that is contributing to economic recovery and social progress in many countries. For this to continue, the mining industry must meet several challenges associated with the start-up of new projects. In a highly complex and uncertain environment, rigorous management of risks remains indispensable in order to repel threats to the success of mining.In this article, a new practical approach to risk management in mining projects is presented. This approach is based on a novel concept called “hazard concentration” and on the multi-criteria analysis method known as the Analytic Hierarchy Process (AHP). The aim of the study is to extend the use of this approach to goldmines throughout Quebec. The work is part of a larger research project of which the aim is to propose a method suitable for managing practically all risks inherent in mining projects.This study shows the importance of taking occupational health and safety (OHS) into account in all operational activities of the mine. All project risks identified by the team can be evaluated. An adaptable database cataloguing about 250 potential hazards in an underground goldmine was constructed. In spite of limitations, the results obtained in this study are potentially applicable throughout the Quebec mining sector. 相似文献
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