摘要:

ABSTRACTField investigations were conducted at three sites in the Washington, D.C., area to detect accumulation patterns of the trace metals, cadmium, copper, lead, and zinc in the soils of urban stormwater detention basins. The research results seemed to indicate that the use of detention basins to control urban stormwater runoff had few harmful effects to fine textured soils with respect to the study trace metals. Although the trace metals, especially lead and zinc, were found to accumulate in the surface soils of the basins, little significant downward movement of metals in the soil profiles had occurred. Accumulations of metals in the surface soils appeared to be a function of microtopography and the resultant residence time of standing water. The fractions of trace metals that were present in a leachable form in surface soils and stormwater solids were small, with median values ranging from 7.7 percent of the total concentration for Cd to 0.01 percent for Pb.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02793.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTMinicomputer interfaced, continuous, noncontact sensing of the ventilatory behavior of the bluegill (Lepomis macrochirus) was used to investigate the response to exposure to solutions of copper and zinc under various modes of application. The results of these studies indicate that fish respond to sublethal concentrations of these toxicants by increasing the average ventilatory rate as well as decreasing the amplitude of the ventilatory signal. Appropriate statistics for the analysis of these data are also described.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02794.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTIn many impoundment dynamic water quality models, the growth of two or more ecologic groups of phytoplankton may be simulated. These ecologic groups are differentiated by growth rates, temperature tolerances, settling rates, and the Michaelis‐Menten half saturation constants for necessary nutrients. In this investigation, the effect of variations in the Michaelis‐Menten half saturation constant for the limiting nutrient when two competing ecologic groups of algae are simulated is examined. In an idealized case, it is demonstrated that uncertainty in the half saturation constant for the limiting nutrient for one ecologic group of algae can significantly affect the simulation results and in some cases could lead to a poorly designed impoundment restoration prog

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02795.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTTree‐ring indices representing seven sites were used to reconstruct monthly summer streamflow in the Occoquan River basin of northern Virginia from 1841 to 1975. Attempts were made to reconstruct flow for each of the months, April through August. Reconstructions for June, July, and August were judged most reliable. Major mid‐summer flow minima persisting for more than one year were reconstructed as having occurred in the early 1870's, the early 1930's, and the mid‐1960's. Aside from these major dry periods, a greater frequency of extreme low flow during individual years is indicated for the entire record than for the most recent 50

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02796.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThis paper deals with the application of a two‐dimensional, saltwater intrusion model to the aquifer in Northern Guam. The model used finite element theory and the Galerkin, weighted‐residual technique as its basis. The Northern Guam lens was discretized into 299 linear, triangular elements and 189 nodes. The model was calibrated using 1978 hydrologic data. The output of the model was compared with measured water levels in six observation wells. The calibrated values of permeability and porosity were then used to verify the model using 1979 data. A calibrated and verified model can be used to make an infinite variety of management and planning studies. In this study, three applications are provided that would be considered typical management runs. Steady state runs were made to compare the four conditions of no pumping, 1978 pumping levels, twice 1978 pumping levels, and five times 1978 pumping levels. The water levels due to these conditions are shown in plan and in cross sections of the aquifer. The effect of zero recharge to the aquifer is next demonstrated for the pumping levels existing during 1978. The final run shows how long the aquifer takes to reach steady state when the pumping rate is increased from the 1978 pumping level to twice that value. The program can be used for numerous other studies for management and planning purpo

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02797.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTTo evaluate the effects of management practices for protection of water quality in White Clay Lake (Wisconsin), surface and lake waters were monitored for a six‐year period before and during structural and management changes for nonpoint pollution source control. The incremental nature of implementing controls combined with the annual variations in sediment and nutrient transport confounded obvious changes in water quality. So, several models were linked together to define loadings from specific land uses and to assess the effects of management changes and animal waste control measures designed to reduce sediment and phosphorus losses. The importance of including the thaw and snowmelt factor in the determination of erosion index for the Universal Soil Loss Equation was demonstrated. Model predictions of average annual phosphorus loading showed a 54 percent reduction following the installation of manure storage facilities and barnyard runoff controls, and a 22 percent reduction through changes in cropland management. The model also predicted a 29 percent reduction in sediment loading. The value of a peripheral wetland for retention of sediment and phosphorus was quantified. Changes in lake water quality attributable to the watershed work were not observed, but maintenance of existing good water quality as a result of this project is anticipate

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02798.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThe likelihood of expanded use of Minnesota's 3 million hectares of peatlands prompted the state to initiate a hydrologic study to characterize these groundwater‐linked systems. Determining the quality of streamflow from these peatlands was an integral part of the study. Peatlands could be differentiated either on the basis of streamflow quality or on soil‐vegetation characteristics. The quality of streamflow from 45 undisturbed peatlands was characterized by collecting samples five times in 1979‐80 and analyzing them for 27 water quality characteristics. Runoff pH, specific conductance, alkalinity, calcium, and magnesium were used to classify the peatlands as bog, transition, or fen. Bog runoff was lower (α= 0.05) in pH, calcium, sodium, manganese, and ammonia nitrogen than fen runoff, but was higher in acidity, color, aluminum, humic and fulvic acid, and chemical oxygen demand than fen runoff. Bogs had more fibric peat of a lower pH than fens; fens exhibited tall woody shrubs which were virtually absent o

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02799.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThe impacts of milled peat mining on runoff quality in northern Minnesota were determined using a multiple watershed approach. The frequency distributions of water quality constituents were used to detect whether runoff from a mined bog differed from that of 15 unmined (control) bogs. Peat mining increased water temperature, suspended sediment, specific conductance and concentrations of acidity, iron, sodium, and nitrogen species, although drinking water standards were not exceeded (α= 0.05). The method presented may be applicable for other nonpoint pollution investigations

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02800.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTChanges in water chemistry, water clarity, and planktonic chlorophyll a were measured as hydrilla (Hydrilla verticillata) abundance increased and then decreased in Lake Baldwin, Florida. Grass carp (Ctenopharyngodon idella) were used to eliminate submersed macrophytes. No major trends in lake pH, conductivity, or total nitrogen concentrations occurred in association with changes in hydrilla levels. Increased Secchi disc transparency and reductions in total alkalinity, calcium, magnesium, potassium, total phosphorus, and chlorophyll a concentrations occurred as hydrilla abundance increased. Large increases in the chemical parameters and a reduction in Secchi disc transparency occurred as hydrilla decreased and was eliminated from the lake by grass carp. The effects of hydrilla on lake water chemistry are related to the percentage of the lake's volume infested with hydrilla and macrophyte standing crop.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02801.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTAs urban expansion outstrips water supplies, the usual solution is to build pipelines to bring in water from sources farther afield. Such water supplies may act as either a leader of urban development or as a follower. In either case, this engineering approach to the provision of water has fostered less than optimal utilization of regional water and land resources for urban growth. More efficient utilization of these resources is achieved when water supply development and urban growth planning are conjoint activities. Water supply planners and land use planners, working together, are able to generate and evaluate the full range of urban development options, including water demand management through conservation. Preferred regional growth plans are achieved using the best mix of water supply and urban growth. The result is a reduced rate of water supply development and a reduction of urban expansion on prime lands. This partnership approach is demonstrated for the Calgary Region under two levels of water conservation.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1983.tb02802.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY