摘要:

ABSTRACT:Water quality monitoring, as a function of society's efforts to manage the environment, is the contact mechanism that management and the public has with the actual water quality in the environment. Water quality monitoring has been studied extensively for many years to ensure that it produces information about water quality conditions. Current efforts to reduce government spending will have negative impacts on those government functions deemed to be non‐responsive to the needs of the public. How well does water quality monitoring inform taxpayers about the status and trends in water quality conditions in the United States? This paper reviews a number of past efforts to “improve” water quality monitoring, discusses barriers to such improvement, and suggests ways that monitoring can be made more accountable for the information it should be producing for public understanding of water quality conditions. In particular, the need for standardization in data analysis and reporting of information to the public, is highli

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03465.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:The St. Lucie River and its tributaries form a major estuarine system on the southeast coast of Florida. This system is strongly affected by anthropogenic influences, including controlled releases of freshwater from Lake Okeechobee through the St. Lucie Canal and an extensive artificial drainage and irrigation system in the watershed. In the present study, three years of biweekly water quality monitoring data from the estuary were examined. The major stresses to the system stem from high variability of the salinity, frequent low dissolved oxygen (DO) events, and light limitation due to high levels of humic substances brought into the system with the fresh water. Nutrient levels also are high. Management goals for the system, including improvement of DO and water clarity, will require reduction in quantity and variability of freshwater releases.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03466.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:Recent technological advances have led to a new generation of landfill liner systems that are highly effective at intercepting and removing leachate. Many of the modern liner systems are so effective that they allow very little or no leakage. Indeed, the amount of leakage through those liners is so minimal that, although it can be theoretically predicted, it cannot be measured with the available monitoring well technology. In addition to being highly effective, some modern liner systems are constructed with two liner layers separated by a drainage medium that detects and removes any leakage through the top liner. These significant improvements in liner system technology have led to the questioning of the necessity for the currently required high number of monitoring wells. Reduction of the number of the monitoring wells and/or of the frequency of sampling would result in substantial cost savings. The present study reports the results of a research project conducted at eleven municipal landfills with modern liner technology throughout the State of Florida. Through actual field data and computer modeling, it was found that the liner systems standards applied in the State of Florida are very effective at preventing any groundwater contamination. Thus, the present monitoring well regulations are too conservative.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03467.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:A methodology has been developed to predict the responses of a range of water supply sources in Wales to global warming scenarios. Hydrologically effective rainfall is predicted from temperature and precipitation for each season based on site specific formulae developed using the Meteorological Office Rainfall and Evaporation Calculation System (MORECS) and UK Surface Water Archive databases. Comparisons are then made between the effects predicted for the scenarios established from equilibrium simulations and the new Hadley Centre High Resolution Model (UKHI) transient mode results. Though very different, both suggest increased stress on water resources late in the hydrological year.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03468.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:Hypolimnetic aeration is a widely used technique for lake restoration and fisheries enhancement. However, system design still depends on application of “safety factors” to observed oxygen demand rates, in large part because actual oxygen demand may be greater after aeration than before. Laboratory incubations of sediment show that sediment oxygen demand (SOD) rates follow mixed order kinetics, with an initial period of zero order reaction, followed by first order kinetics. The transition from zero to first order kinetics may correspond to the transition from laminar to turbulent flow. This suggests that SOD reaction kinetics are governed by thickness of the diffusive sublayer adjacent to the sediments. Therefore, zero and first order reaction regions correspond with oxygen diffusion limitation and substrate limitation, respectively. Such a mechanism would account for the induced oxygen demand observed following hypolimnetic aeration and would reconcile differences in SOD reaction orders noted in the literature. This paper describes development of equations based on laboratory SOD incubations for predicting induced oxygen demand following hypolimnetic aerat

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03469.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03470.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:Streamflow for 67 years was simulated for Coon Creek at Coon Valley, Wisconsin, for three conditions in the drainage basin: (1) conditions in the 1930s; (2) conditions in the 1970s, excluding flood‐detention reservoirs; and (3) conditions in the 1970s, including flood‐detention reservoirs. These simulations showed that the changes in agricultural practices over 40 years (1940–80) reduced the 100‐year flood by 53 percent (from 38,900 to 18,300 cubic feet per second). The flood‐detention reservoirs reduced the 100‐year flood by an additional 17 percent (to 15,100 cubic feet per second). The simulation was accomplished by calibrating a precipitation‐runoff model to observed rainfall and runoff during two separate periods (1934–40 and 1978–81). Comparisons of model simulations showed that differences between the model calibrations for the two periods were statistically significant at the 95 percent

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03471.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:Rainfall data products generated with the national network of WSR‐88D radars are an important new data source provided by the National Weather Service. Radar‐based data include rainfall depth on an hourly basis for grid cells that are nominally 4 km square. The availability of such data enables application of improved techniques for rainfall‐runoff simulation. A simple quasi‐distributed approach that applies a linear runoff transform to grid‐ded rainfall excess has been developed. The approach is an adaptation of the Clark conceptual runoff model, which employs translation and linear storage. Data development for, and results of, an initial application to a 4160 km2watershed in the Midwestern U.S. are il

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03472.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:This paper describes a concept for identification and ranking of outdoor recreation habitats using principles of ecology as a guide. The Habitat Evaluation Procedures (HEP) is a commonly used technique for assessment of human impacts on the vigor of wildlife species, and serves as the model for the Recreation Habitat Analysis Method (RHAM). Recreation activities are dependent on habitat attributes for their success just as are wildlife species. A sample model is described for recreation activities at large, multipurpose lakes. RHAM could be applied to recreation experiences in a variety of settings including smaller water bodies and riparian and terrestrial ecosystems.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03473.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACT:The relation between landscape characteristics and water chemistry on the Delmarva Peninsula can be determined through a principal‐component analysis of basin characteristics. Two basin types were defined by factor scores: (1) well‐drained basins, characterized by combinations of a low percentage of forest cover, a low percentage of poorly drained soil, and elevated channel slope; and (2) poorly drained basins, characterized by a combinations of an elevated percentage of forest cover, an elevated percentage of poorly drained soil, and low channel slopes. Results from base‐flow sampling of 29 basins during spring 1991 indicate that water chemistry of the two basin types differ significantly. Concentrations of calcium, magnesium, potassium, alkalinity, chloride, and nitrate are elevated in well‐drained basins, and specific conductance is elevated. Concentrations of aluminum, dissolved organic carbon, sodium, and silica are elevated in poorly drained basins whereas specific conductance is low. The chemical patterns found in well‐drained basins can be attributed to the application of agricultural chemicals, and those in poorly drained basins can be attributed to ground‐water flowpaths. These results indicate that basin types determined by a quantitative analysis of basin characteristics can be related statistically to differences in base‐flow chemistry, and that the observed statistical differences can be related to major processes that affect wa

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1996.tb03474.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY