bluuebunny/crossref_metadata_2025 huggingface dataset:
A GEOGRAPHIC INFORMATION SYSTEMS APPROACH TO WELLHEAD PROTECTION1
Authors: Hammen John L. , Gerla Philip J.
Published: June 2007

ABSTRACT: The 1986 Amendments to the Safe Drinking Water Act mandate a multifaceted approach to wellhead protection. This approach includes: (1) delineating wellhead protection areas; (2) identifying and managing potential contaminants; (3) developing contingency plans in the event of weilfield contamination; (4) siting new wells; and (5) encouraging public participation. These elements encompass technical, administrative, and educational considerations. In functioning both as a research tool and as a decision support system, a geographic information system (GIS) is shown to have proven utility in addressing these issues. This article describes the application of common GIS functionality in facilitating a comprehensive wellhead protection scheme for an agricultural municipality in North Dakota.
SIMULATION OF INTEGRATED SURFACE WATER AND GROUND WATER SYSTEMS ‐ MODEL FORMULATION1
Authors: Yan Jiansheng , Smith Keith R.
Published: June 2007

ABSTRACT: The unique characteristics of the hydrogeologic system of south Florida (flat topography, sandy soils, high water table, and highly developed canal system) cause significant interactions between ground water and surface water systems. Interaction processes involve infiltration, evapotranspiration (ET), runoff, and exchange of flow (seepage) between streams and aquifers. These interaction processes cannot be accurately simulated by either a surface water model or a ground water model alone because surface water models generally oversimplify ground water movement and ground water models generally oversimplify surface water movement. Estimates of the many components of flow between surface water and ground water (such as recharge and ET) made by the two types of models are often inconsistent. The inconsistencies are the result of differences in the calibration components and the model structures, and can affect the confidence level of the model application. In order to improve model results, a framework for developing a model which integrates a surface water model and a ground water model is presented. Dade County, Florida, is used as an example in developing the concepts of the integrated model. The conceptual model is based on the need to evaluate water supply management options involving the conjunctive use of surface water and groundwater, as well as the evaluation of the impacts of proposed wellfields. The mathematical structure of the integrated model is based on the South Florida Water Management Model (SFWMM) (MacVicar et al., 1984) and A Modular Three‐Dimensional Finite‐Difference Groundwater Flow Model (MODFLOW) (McDonald and Harbaugh, 1988).
ECONOMIC IMPLICATIONS OF PHOSPHORUS LOADING POLICIES FOR PASTURE LAND APPLICATIONS OF POULTRY LITTER1
Authors: Govindasamy Ramu , Cochran Mark J. , Buchberger Eta
Published: June 2007

ABSTRACT: Non‐point source pollution created by agriculture is one of the major issues of intensive production. Recent studies indicate that the eutrophication from agricultural non‐point source pollution, especially from phosphorus, is of growing concern. The objectives of this paper are to measure the economic opportunity costs of a proposed phosphorus management policy that targets soils with elevated phosphorus levels and examine the impacts of alternative policies such as Pigouvian taxes on the optimal use of litter. The study focuses on land applications of poultry litter in the Muddy Fork watershed of the Illinois River in Northwest Arkansas. The analysis indicates that restriction of litter applications on soils with elevated phosphorus levels will significantly reduce the net returns generated from forage production, resulting in an environmental policy with a high opportunity cost for producers. An analysis of alternative Pigouvian tax policies shows that a smaller tax per ton of litter applied can achieve the same litter control as that of a larger tax on a per acre basis.
BMP IMPACTS ON WATERSHED RUNOFF, SEDIMENT, AND NUTRIENT YIELDS1
Authors: Park S. W. , Mostaghimi S. , Cooke R. A. , McClellan P W.
Published: June 2007

ABSTRACT: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed‐averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm‐ and post‐BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.
EXPOSURE ASSESSMENT OF POPULATIONS USING ENVIRONMENTAL MODELING, DEMOGRAPHIC ANALYSIS, AND GIS1
Authors: Maslia Morris L. , Aral Mustafa M. , Williams Robert C. , Susten Allan S. , Heitgerd Janet L.
Published: June 2007

ABSTRACT: Simulation of ground‐water flow and fate of contaminants in the subsurface environment constitutes a major phase of most environmental assessment and site remediation studies. These simulation studies yield information on spatial and temporal distributions of contaminants in the subsurface media. An important use of this information is to conduct exposure assessment studies. Spatial and temporal distributions of both chemical concentrations and exposed populations render this integrated exposure analysis task rather difficult. Geographic Information Systems (GIS), on the other hand, provide a platform in which layered, spatially distributed databases can be manipulated with ease, thereby simplifying exposure analysis tasks significantly. In this paper, we describe procedures that combine the simulation models and demographic databases under a GIS platform to automate the exposure assessment phase of a typical health assessment study. Procedures developed herein significantly simplify the post‐processing phase of the analysis, and render the overall task more ‘user friendly.’ A site‐specific application is included as a demonstration of the proposed process.
ARTIFICIAL RECHARGE IN SASKATCHEWAN: CURRENT DEVELOPMENTS1
Authors: Digney J. E. , Gillies J. A.
Published: June 2007

ABSTRACT: The use of artificial recharge in Saskatchewan and the rest of Canada to improve rural community and farmstead domestic water supply has great potential. Approximately 75 percent of the people in rural Saskatchewan and 26 percent of all the people in Canada are dependent on ground water for their domestic water supply. Typically, this water is highly mineralized and is often unpalatable due to odor and taste. A source of readily available, high quality water to eliminate expensive chemical treatment of available water and long distance hauling would be of significant value to rural residents. Storage of high quality water in aquifers by injection through wells has been documented and has been shown to depend on the use of a surface water catchment system to provide the high quality water. Since air entrainment or formation clogging can occur in poorly operated recharge schemes, development of proper design and operation of recharging procedure is required. This can be accomplished by using an injection response computer model and a properly designed injection system. Small scale artificial recharge projects will provide a valuable commodity to rural water users and will promote sustainable and conjunctive use of surface and ground water resources.
HYDRODYNAMIC MODELING OF THE CARSON RIVER AND LAHONTAN RESERVOIR, NEVADA1
Authors: Warwick John J. , Heim Kenneth J.
Published: June 2007

ABSTRACT: The RIVMOD hydrodynamic model was used to route upstream flows through a 115 km section of the Carson River and Lahontan Reservoir, Nevada. RIVMOD results will later be used to predict sediment movement and ultimately to determine mercury transport within the river/reservoir system. Significant modifications to the model computer code were necessary to represent the narrow, steeply sloping rectangular channel and relatively shallow sloping floodplain of the Carson River and its confluence with the Lahontan Reservoir. These changes include expansion of the continuity and momentum equations to account for rapidly changing channel widths along with the characterization of a complex cross‐sectional shape. This modified version of the RIVMOD model can handle shallower side slopes and much more severe flood flow simulations than the original version. A 0.25 km spatial increment was required in the zone of confluence between the river and reservoir. Model predictions show excellent agreement with observed downstream flow and reservoir stage for the entire 1986 water year, which includes one of the most severe flood events of recent record. (KEY TERMS: hydraulics; modeling; simulation; surface water hydrology.)
A STEPWISE PROCEDURE TO DESIGN PLUVIAL DRAINAGE SYSTEMS IN AGRICULTURAL ZONES1
Authors: Sánchez‐Bribiesca J. L. , Fuentes‐Mariles O. A. , Gracia‐Sánchez J.
Published: June 2007

ABSTRACT: This paper describes a procedure to design pluvial drainage systems in such a way as to prevent large excavation volumes and erosive velocities. To this end the storage capacity of the channel system is taken into account. In a preliminary step, the procedure employs an approximate method to determine the channel dimensions. Therefore, the dimensions are adjusted by means of a numerical method of solution of the unsteady flow equations. An example is included.
ESTIMATION OF ENERGY REQUIREMENTS OF MORNING DEW EVAPORATION FROM LEAF SURFACES1
Authors: Abtew W. , Obeysekera J.
Published: June 2007

ABSTRACT: Evapotranspiration from vegetation is generally computed without consideration for early morning energy loss involved in drying wet leaf surfaces. In humid areas where dew formation is frequent, estimation of energy requirements for evaporating dew should be of interest. In this study, sensible heat flux (H) was computed from wind and temperature profile measurements over the study site. A leaf wetness sensor was used to measure the duration of evaporation from an exposed leaf surface, and net radiation was measured with a radiometer. The energy flux during the period of wet leaf surface evaporation was integrated over time. A cattail lysimeter situated at the site indicated the time when evapotranspiration started after wet leaves were dry. The energy requirements to dry an exposed wet leaf surface was estimated using energy balance methods. The mean value based on 44 days of observations from mid February to early May of 1993 indicates that the energy required to evaporate dew from openly exposed wet leaves was 5 percent of the total daily evapotranspiration of cattails with a coefficient of variation of 0.72. The mean time required to evaporate dew from exposed leaf surfaces from the onset of positive net radiation was 78 minutes. The mean dew evaporation in a morning from an exposed leaf surface was 0.16 mm with a maximum value of 0.41 mm. The energy required to dry wet leaves is a factor that should be considered when modeling evapotranspiration at hourly or shorter time intervals. Also, physical evapotranspiration models need to account for energy requirements for drying dew and rainfall wetted leaves.
USE AND MISUSE OF COMPLEX MODELS: EXAMPLES FROM WATER DEMAND MANAGEMENT1
Authors: Parker Michael , Thompson James G. , Reynolds Robert R. , Smith Michael D.
Published: June 2007

ABSTRACT: The power of computers has increased in recent decades, and one might expect improved management to result because decisions can be made with understanding available only via models. However, there is potential for quite the opposite: poor decisions due to unrealistic model output generated by users without access to appropriate training in the use of models. We discuss and, by reference to water demand models (IWR‐MAIN, MWD‐MAIN), illustrate three areas in which unintended errors of judgment by untrained personnel may cause difficulty:

Attributes of management models; if output from any type of model has no measure of confidence, then results may be over‐ or undervalued

Input data; with complex models, problems here typically will be difficult to detect.

Calibration and history‐matching (verification); if these steps or data are combined, then users should be less trustful of model output than otherwise.

Because all models have weaknesses and because there always is uncertainty about output from any model, we end with suggestions for coping with complex models. Monitoring programs play a central role in such efforts because they can identify discrepancies between model predictions and actual events and because they can ensure time is available to develop solutions for problems unanticipated in the modeling effort.
IMPACT OF IRRIGATION WELLS ON BASEFLOW OF THE BIG BLUE RWER, NEBRASKA1
Authors: Ali Tabidian M. , Pederson Darryll T.
Published: June 2007

ABSTRACT: The Kansas‐Nebraska Big Blue River compact requires that the state of Nebraska insure a minimum flow of the Big Blue River across the state line. There are two options that the state of Nebraska may use to ensure minimum flows. The obvious option is to limit surface‐water irrigators along the river. However, under the terms of the compact, a second option may be to regulate irrigation wells that are within one mile of the river and were installed after November 1, 1968. The objective of this study is to quantify the effects of 17 irrigation wells that may be regulated on baseflow of the Big Blue River. A finite‐element model is used to study the hydrogeologic system between DeWitt and Beatrice, Nebraska. The 17 wells that may be regulated are located between these towns and are developed in sediments deposited in a cross‐cutting paleovalley anchor alluvium associated with the Big Blue River. While there wore considerable existing data, additional data were gathered by drilling an additional nine test holes, conducting several aquifer tests, stream‐stage measurements, and baseflow calculation through extensive stream‐discharge measurements, establishment of a ground water‐level monitoring network, determining the amount of water pumped for irrigation and municipal use in the area, and a short‐term precipitation network. The model was calibrated using observed baseflow and ground water level data. The model clearly shows that regulating the 17 wells to maintain baseflow would have a minimal effect on the overall water budget. This is reasonable, especially considering that there are over 250 irrigation wells in the project area. The 17 wells considered pumped only 6 percent of the total pumpage within the modeled area during the irrigation season of 1984. The computer model provides the documentation needed to demonstrate this fact. Although much of the resources spent and a significant amount of hydrogeologic data are being collected over a period of three years on a relatively small area, the simulation model could be improved through further field testing of the aquifer and stream‐bed sediment characteristics and quantification of ground water recharge, discharge, and evapotranspiration rates.
MEETING FUTURE PUBLIC WATER SUPPLY NEEDS: A SOUTHWEST PERSPECTIVE1
Authors: Maddock Thomas S. , Hines Walter G.
Published: June 2007

ABSTRACT: Most southwestern cities were founded along rivers or in areas having springs or readily available ground water. Because of the generally sparse precipitation, the renewable fresh water supply in the Southwest is smaller than most other areas of the United States. Despite the arid climate, water use has increased rapidly, first in the form of irrigation, and more recently the use in cities. This has caused extensive development of local water resources and overdraft of ground water basins in some areas. It is difficult to implement new local supplies and importation projects due to a myriad of environmental and legal constraints and a general shortage of public funds. Various opportunities and plans for water management, both on the demand and supply sides, are discussed. Evolving water strategies in four metropolitan areas ‐ El Paso, Albuquerque, Las Vegas, and Phoenix ‐ and issues regarding the Central Arizona Project are presented.
INFLUENCING WATER LEGISLATWE DEVELOPMENT WHAT TO DO AND WHAT TO AVOID1
Authors: Davis Ray Jay , Sherk George William , Phelps Donald
Published: June 2007

ABSTRACT: Whomever would affect water policy development must influence the water legislative process. This paper discusses in the context of the Model State Water Allocation Code the following ten ideas about doing that: (1) seek the right timing for enactment; (2) set modest goals; (3) prepare a well‐drafted proposal; (4) recognize diversity by offering legislative choices; (5) consider the impacts of adoption; (6) make alliances; (7) respect executive influence; (8) become involved in legislative interaction; (9) be flexible; and (10) persist. Heeding these ideas, although not guaranteeing enactment, is sure to be educational for participants and useful to legislators.
ESTIMATING NONPOINT SOURCE POLLUTION LOADS WITH A GIS SCREENING MODEL1
Authors: Adamus Christine L. , Bergman Martinus J.
Published: June 2007

ABSTRACT: The St. Johns River Water Management District (SJR‐WMD) is using a Geographic Information System (GIS) screening model to estimate annual nonpoint source pollution loads to surface waters and determine nonpoint source pollution problem areas within the SJRWMD. The model is a significant improvement over current practice because it is contained entirely within the district's GIS software, resulting in greater flexibility and efficiency, and useful visualization capabilities. Model inputs consist of five spatial data layers, runoff coefficients, mean runoff concentrations, and stormwater treatment efficiencies. The spatial data layers are: existing land use, future land use, soils, rainfall, and hydrologic boundaries. These data layers are processed using the analytical capabilities of a cell‐based GIS. Model output consists of seven spatial data layers: runoff, total nitrogen, total phosphorous, suspended solids, biochemical oxygen demand, lead, and zinc. Model output can be examined visually or summarized numerically by drainage basin. Results are reported for only one of the SJRWMD's ten major drainage basins, the lower St. Johns River basin. The model was created to serve a major planning effort at the SJRWMD; results are being actively used to address nonpoint source pollution problems.
IMPACTS OF A SEVERE SUSTAINED DROUGHT ON COLORADO RWER WATER RESOURCES1
Authors: Harding Benjamin L. , Sangoyomi Taiye B. , Payton Elizabeth A.
Published: June 2007

ABSTRACT: The impacts of a severe sustained drought on Colorado River system water resources were investigated by simulating the physical and institutional constraints within the Colorado River Basin and testing the response of the system to different hydrologic scenarios. Simulations using Hydrosphere's Colorado River Model compared a 38‐year severe sustained drought derived from 500 years of reconstructed streamflows for the Colorado River basin with a 38‐year streamflow trace extracted from the recent historic record. The impacts of the severe drought on streamflows, water allocation, storage, hydropower generation, and salinity were assessed. Estimated deliveries to consumptive uses in the Upper Basin states of Colorado, Utah, Wyoming, New Mexico, and northern Arizona were heavily affected by the severe drought, while the Lower Basin states of California, Nevada, and Arizona suffered only slight shortages. Upper Basin reservoirs and streamflows were also more heavily affected than those in the Lower Basin by the severe drought. System‐wide, total hydropower generation was 84 percent less in the drought scenario than in the historical stream‐flow scenario. Annual, flow‐weighted salinity below Lake Mead exceeded 1200 ppm for six years during the deepest portion of the severe drought. The salinity levels in the historical hydrology scenario never exceeded 1100 ppm.
ASSESSING ENVIRONMENTAL EFFECTS OF SEVERE SUSTAINED DROUGHT1
Authors: Hardy Thomas B.
Published: June 2007

ABSTRACT: Evaluation criteria for reservoir and stream resources were developed to provide decision makers with feedback on environmental consequences of water allocation decisions under conditions of severe sustained drought within the Colorado River Basin by using the AZCOL gaming simulation model. Seven categories of flow dependent resources were identified which highlight resource states associated with reservoirs or river reaches within the AZCOL model. AZCOL directly simulates impact of water management decisions on five resource categories: threatened, endangered or sensitive fish; native nonlisted fish; wetland and riparian elements; national or state wildlife refuges; and hatcheries or other flow dependent facilities. Two additional categories ‐ cold and warm water sport fish ‐ are not modeled explicitly but are incorporated in the evaluation of monetary benefits from recreation on Colorado River waters. Each resource category was characterized at each time step in the simulation according to one of four environmental states: stable, threatened, endangered, or extirpated. Changes in resource states were modeled by time and flow‐dependent decision criteria tied to either reservoir level or stream flows within the AZCOL model structure. Gaming results using the AZCOL model indicate environmental impacts would be substantial and that water allocation decisions directly impacted environmental resource states.
COMPARATIVE EVALUATION OF LAND COVER DATA SOURCES FOR EROSION PREDICTION1
Authors: Fraser Robert H. , Warren Maureen V. , Barten Paul K
Published: June 2007

ABSTRACT: A fundamental problem in protecting surface drinking water supplies is the identification of sites highly susceptible to soil erosion and other forms of nonpoint source (NPS) pollution. The New York City Department of Environmental Protection is trying to identify erodible sites as part of a program aimed at avoiding costly filtration. New York City's 2,000 square mile watershed system is well suited for analysis with geographic information systems (GIS); an increasingly important tool to determine the spatial distribution of sensitive NPS pollution areas. This study used a GIS to compare three land cover sources for input into the Modified Universal Soil Loss Equation (MUSLE), a model estimating soil loss from rangeland and forests, for a tributary watershed within New York City's water supply system. Sources included both conventional data (aerial photography) and Landsat data (MSS and TM images). Although land cover classifications varied significantly across these sources, location‐specific and aggregate watershed predictions of the MUSLE were very similar. We conclude that using Landsat TM imagery with a hybrid classification algorithm provides a rapid, objective means of developing large area land cover databases for use in the MUSLE, thus presenting an attractive alternative to photo interpretation.
NONPOINT SOURCE POLLUTION POTENTIAL IN AN AGRICULTURAL WATERSHED IN NORTHWESTERN PENNSYLVANIA1
Authors: Brenner Fred J. , Mondok James J.
Published: June 2007

ABSTRACT: A 155,947 ha portion of the Shenango River watershed in western Pennsylvania was evaluated as to the potential impact of agriculture drainage on water quality. Approximately a third of the area is being used as either cropland or pasture with approximately an equal percentage in forest lands. Eleven subwatersheds were evaluated as to their potential for nonpoint source pollution according to the criteria established by the Pennsylvania Department of Environmental Resources for the Chesapeake Bay Pollution Abatement Program. The individual components and overall rating for each subwatershed were then evaluated as to their correlation with four water quality variables based on 104 samples collected at 26 sampling stations throughout the watershed. There was a significant correlation between the overall rating factor for each subwatershed and each of the four water quality variables. In general, the watershed delivery factor, animal nutrient factor, and management factors were correlated with fecal coliform and phosphorus in the receiving streams, whereas the ground water delivery factor appeared to be more important in determining nitrate concentrations in these streams. These results indicate that manure and nutrient management, along with the exclusion of livestock from streams and the enhancement and/or replacement of riparian wetlands, are important approaches in reducing agricultural impacts in fresh water ecosystems.
WATERSHED ANALYSIS AS A FRAMEWORK FOR IMPLEMENTING ECOSYSTEM MANAGEMENT1
Authors: Montgomery David R. , Grant Gordon E. , Sullivan Kathleen
Published: June 2007

ABSTRACT: Implementing ecosystem approaches to land use decision making and land management requires new methods for linking science and planning. Greater integration is crucial because under ecosystem management sustainable levels of resource use are determined by coupling management objectives to landscape capabilities and capacities. Recent proposals for implementing ecosystem management employ analyses organized at a hierarchy of scales for analysis and planning. Within this hierarchy, watershed analysis provides a framework for delineating the spatial distribution and linkages between physical processes and biological communities in an appropriate physical context: the watershed. Several such methods are currently in use in the western United States, and although there is no universal procedure for either implementing watershed analysis or linking the results to planning, there are a number of essential elements. A series of questions on landscape‐level ecological processes, history condition, and response potential guide watershed analysis. Individual analysis modules are structured around answering these questions through a spatially‐distributed, process‐based approach. The planning framework linked to watershed analysis uses this information to either manage environmental impacts or to identify desired conditions and develop land management prescriptions to achieve these conditions. Watershed analysis offers a number of distinct advantages over contemporary environmental analyses for designing land management scenarios compatible with balancing environmental and economic objectives.
INTEGRATED WATER MANAGEMENT: CONTENDING WITH GARBAGE CAN DECISIONMAIUNG IN ORGANIZED ANARCHIES1
Authors: Deyle Robert E.
Published: June 2007

ABSTRACT: Water management in the United States has historically been characterized by a decisionmaking system that is fragmented along three dimensions: (1) physical, (2) institutional, and (3) political‐technical. The result is often ‘garbage can’ decision‐making in open decisionmaking structures with the attributes of an ‘organized anarchy’ rather than the rational, comprehensive decisionmaking prescribed for water management. A case study of water quality management decisionmaking in the New York Finger Lakes is used to illustrate how the garbage can model can illuminate the forces that operate in fragmented water management. Interorganizational decisionmaking theory and experience from water management integration initiatives are then applied to assess what strategies may be effective in reducing the organizational anarchy that results from fragmented water management institutions.
BIOGEOCIIEMISTRY OF AN OLD‐GROWTH FORESTED WATERSHED, OLYMPIC NATIONAL PARK, WASHINGTON1
Authors: Edmonds Robert L. , Thomas Ted B. , Blew Roger D.
Published: June 2007

ABSTRACT: The biogeochemistry of a coastal old‐growth forested watershed in Olympic National Park, Washington, was examined. Objectives were to determine: (1) concentrations of major cations and anions and dissolved organic C (DOC) in precipitation, throughfall, stemflow, soil solution and the stream; (2) nutrient input/output budgets; and (3) nutrient retention mechanisms in the watershed. Stemilow was more acidic (pH 4.0–4.5) than throughfall (pH 5.1) and precipitation (pH 5.3). Organic acids were important contributors to acidity in throughfall and stemflow and tree species influenced pH. Soil solution pH averaged 6.2 at 40 cm depth. Stream pH was higher (7.6). Sodium (54.0 μeq L‐1) and Cl (57.6 μeq L−1) were the dominant ions in precipitation, reflecting the close proximity to the ocean. Throughfall and stemflow were generally enriched in cations, especially K. Cation concentrations in soil solutions were generally less than those in stemilow. Ion concentrations increased in the stream. Dominant ions were Ca (759.7 μeq L−1), Na (174.4 μeq L−1), HCO3 (592.0 μeq L−1), and SO4 (331.5 μeq L−1) with seasonal peaks in the fall. Bedrock weathering strongly influenced stream chemistry. Highest average NO3 concentrations were in the stream (5.2 μeq L−1) with seasonal peaks in the fall and lowest concentrations in the growing season. Nitrogen losses were similar to inputs; annual inputs were 4.8 kg/ha (not including fixation) and stream losses were 7.1 kg/ha. Despite the age and successional status of the forest, plant uptake is an important N retention mechanism in this watershed.
FREQUENCY‐DURATION ANALYSIS OF DISSOLVED‐OXYGEN CONCENTRATIONS IN TWO SOUTHWESTERN WISCONSIN STREAMS1
Authors: Greb Steven R. , Graczyk David J.
Published: June 2007

ABSTRACT: Historically, dissolved‐oxygen (DO) data have been collected in the same manner as other water‐quality constituents, typically at infrequent intervals as a grab sample or an instantaneous meter reading. Recent years have seen an increase in continuous water‐quality monitoring with electronic dataloggers. This new technique requires new approaches in the statistical analysis of the continuous record. This paper presents an application of frequency‐duration analysis to the continuous DO records of a cold and a warm water stream in rural southwestern Wisconsin. This method offers a quick, concise way to summarize large time‐series data bases in an easily interpretable manner. Even though the two streams had similar mean DO concentrations, frequency‐duration analyses showed distinct differences in their DO‐concentration regime. This type of analysis also may be useful in relating DO concentrations to biological effects and in predicting low DO occurrences.
MANAGING UNDERGROUND STORAGE TANKS IN URBAN ENVIRONMENTS: A GEOGRAPHIC INFORMATION SYSTEMS APPROACH1
Authors: Hudak Paul F. , Speas Roger K. , Schoolmaster F. Andrew
Published: June 2007

ABSTRACT: Fuels contained in underground storage tanks (USTs) are a major source of soil and ground water contamination. Effective management of the problem at the urban level is difficult due to a large number of tanks and a vast array of factors (e.g., tank characteristics, geology) that determine environmental hazards. The problem is compounded by frequent abandonment and reuse of service stations, which makes it difficult to track the status of underground tanks. Geographic information systems (GIS) are ideally suited to organizing location and attribute data for variables that are pertinent to the UST management problem. A GIS‐based UST management system was developed and applied to 136 current and former gasoline service stations in Denton, Texas. The system is effective for tank inventory and can be applied in a proactive fashion to identify potentially problematic facilities. In the event of a leak or spill, the management system can support the implementation of reactive measures to mitigate subsurface contamination. Potential beneficiaries of such a system include planning departments, environmental regulatory agencies, emergency management officials, lending institutions, gasoline distributors, and oil companies.
HYDRODYNAMIC CONTROL OF AN EMERGENT AQUATIC PLANT (SCIRPUS ACUTUS) IN OPEN CHANNELS1
Authors: Groeneveld David P. , French Richard H.
Published: June 2007

ABSTRACT:Control of emergent aquatic plants such as tule (Scirpus acutusMuhl.; Bigel.) is of direct interest to managers of surface waters in Western North America. Where conditions of water velocity and depth occur that permit this and similar species to colonize and grow, their clonal habit may restrict, or even block, open channels within several seasons after their establishment. Fortunately, sufficient flow depth and velocity naturally prevent these plants from growing into and blocking channels. We investigated physical constraints for tule stem growth with the ultimate intent to apply this knowledge in rehabilitating 60 miles of the diverted Owens River in Eastern California, presently choked with emergent growth. Bending stress resulting from hydrodynamic drag on tule stems was found to induce lodging; permanent deformation and consequent loss of function. The depth‐velocity envelope describing this process (at 95 percent confidence) isuD/d= 12.8 where u = average velocity acting upon the stem (m/s), D = local depth of flow (m), and d = tule stem diameter at the point of attachment (m). Maintaining a discharge or reconfiguring a channel so this critical depth‐velocity‐stem diameter envelope is exceeded (predictable using flow models) through the summer growing period should prevent encroachment into an active channel.
A FRAMEWORK FOR PHOSPHORUS TRANSPORT MODELING IN THE LAKE OKEECHOBEE WATERSHED1
Authors: Wagner R. A. , Tisdale T S. , Zhang J.
Published: June 2007

ABSTRACT: A modeling framework was developed to determine phosphorus loadings to Lake Okeechobee from watersheds located north of the lake. This framework consists of the land‐based model CREAMS‐WT, the in‐stream transport model QUAL2E, and an interface procedure to format the land‐based model output for use by the in‐stream model. QUAL2E hydraulics and water quality routines were modified to account for flow routing and phosphorus retention in both wetlands and stream channels. Phosphorus loadings obtained from previous applications of CREAMS‐WT were used by QUAL2E, and calibration and verification showed that QUAL2E accurately simulated seasonal and annual phosphorus loadings from a watershed. Sensitivity and uncertainty analyses indicated that the accuracy of monthly loadings can be improved by using better estimates of in‐stream phosphorus decay rates, ground water phosphorus concentrations, and runoff phosphorus concentrations as input to QUAL2E.
RUNOFF AND SEDIMENT YIELD UNDER GRAZING IN FOOTHILLS FESCUE GRASSLANDS OF ALBERTA1
Authors: Anne Naeth M. , Chanasyk David S.
Published: June 2007

ABSTRACT: Grazing can have a profound impact on infiltration and thus runoff and erosion. The objectives of this study were to quantify the effects of select grazing systems on rainfall and snowmelt induced runoff and sediment yield from sloped areas of the foothills fescue grasslands of Alberta, Canada. The effects of two grazing intensities (heavy and very heavy) for two durations (short duration and continuous throughout the growing season) were compared to an ungrazed control between June 1988 and April 1991. Runoff was measured using 1‐rn2 runoff frames and collection bucket systems. Sediment yields were then determined on samples from the collected runoff.

Snowmelt was the dominant source of runoff. Snowmelt runoff was higher from the heavily grazed areas than from the very heavily grazed areas, due to the higher standing vegetation which accumulated snow in the former areas. Sediment yields as a result of snowmelt were generally low in all areas. Only a few summer storms caused runoff. Runoff volumes and sediment yields from summer rainstorms were low, due to low rainfall and to generally dry antecedent soil moisture conditions. The greatest risk of summer runoff, and thus sediment yield, appears to occur in August.
OCCURRENCE OF PESTICIDES IN GROUND WATER OF THE OZARK PLATEAUS PROVINCE1
Authors: Adamski James C. , Pugh Aaron L.
Published: June 2007

ABSTRACT: Pesticides were detected in ground‐water samples collected from 20 springs and nine wells in the Ozark Plateaus Province of Arkansas, Kansas, Missouri, and Oklahoma. From April through September 1993, water samples were collected from 50 shallow domestic wells and 50 springs in the Springfield Plateau and Ozark aquifers and analyzed for 47 pesticides and metabolites. Pesticides were detected in 17 water samples from the Springfield Plateau aquifer and 12 water samples from the Ozark aquifer. Fourteen pesticides were detected, with a maximum of four pesticides detected in any one sample. The most commonly detected pesticides were atrazine (14 detections), prometon (11 detections), and tebuthiuron (seven detections). P, P' DDE, a metabolite of DDT, was detected in water samples from three wells and one spring. The remaining pesticides were detected in three or less samples. The occurrence and distribution of pesticides probably are related to the local land use near a sampling site. Pesticide detections were significantly related to aquifer, site type, and discharge of springs.
PATTERN OF GROUND‐WATER LEVEL DECLINE IN THE HIGH PLAINS AQUIFER NEBRASKA1
Authors: Davis Ralph K , Pederson Darryll T
Published: June 2007

ABSTRACT: Ground‐water level decline patterns in parts of Nebraska conform to the circular island concept of Bredehoeft et al. (1982), which indicates how water is derived by wells developed in a circular island. If elongated, the center of the island corresponds to a regional ground‐water divide while the shoreline corresponds to a regional river. In both versions, ground‐water table elevation is a function of recharge and transmissivity. A dynamic equilibrium exists such that the gradient of the water table will convey all recharge to discharge areas. Withdrawals of ground water result initially in mining, with a new equilibrium attained when pumping equals capture. During early development, capture is an important source of water in discharge areas, while mining is more significant in recharge areas. The pattern observed in many areas shows the greatest ground‐water level decline in the vicinity of ground‐water divides and the steepest gradient near regional rivers. A similar pattern has been observed adjacent to the Arkansas River in south‐central Kansas. Similar decline patterns can be modeled for a hypothetical ground‐water basin. This is of major importance to water‐resource managers because it dictates that management programs be applied to the entire hydrologic system.
ECOSYSTEM MANAGEMENT: A LANDSCAPE ECOLOGY PERSPECTWE1
Authors: Jensen Mark E. , Bourgeron Patrick , Everett Richardf , Goodman Iris
Published: June 2007

ABSTRACT:Ecosystem management is an evolving philosophy that many government agencies have adopted in the multiple‐use, sustained‐yield management of federal lands. The primary objective of this philosophy is to sustain the integrity of ecosystems (i.e., their function, composition, and structure) for future generations while providing immediate goods and services to an increasingly diverse public. This objective can be achieved through integrated land evaluation and optimal land use planning that promotes the maintenance or development of landscape patterns and processes that meet societal expectations within the limits of the land's ecological potentials. Landscape ecology and conservation biology principles are critical components of this philosophy. This paper describes how some of these principles can be efficiently used in formulating a framework for ecosystem management on federal lands. The role of landscape ecology in ecosystem characterization and description is stressed, and the appropriateness of integrated ecological assessments to ecosystem management is discussed.
SOUND POLICY OR SMOKE AND MIRRORS: DOES ECOSYSTEM MANAGEMENT MAKE SENSE?1
Authors: Fitzsimmons Allan K
Published: June 2007

ABSTRACT: Protection of ecosystems as entities on the landscape has attracted a wide range of support. Ecosystem‐based public policies are claimed to be more effective, efficient, and scientifically sound than other approaches to environmental and natural resource policy. The ecosystem concept was never intended to serve as a public policy guide or to determine landscape units for land management purposes. This paper critically examines the use of the ecosystem concept in public policy and land use management and analyzes the proposed rule to manage the National Forest System according to ecosystem management principles. The concept is found to be unsuitable as a basis for guiding environmental and natural resource public policies in general while the proposed rule to manage the national forests according to ecosystem management principles is shown to be incoherent.
A NEW ICE JAM DATABASE1
Authors: White Kathleen D.
Published: June 2007

ABSTRACT: Ice jam data are often difficult to locate, and doing so requires a search of many different data sources. The US Army Cold Regions Research and Engineering Laboratory (CRREL) has compiled an Ice Jam Database that provides information on nearly 9300 ice events in the United States. The information may be quantitative (e.g., event stage or discharge), qualitative (e.g., a narrative description), or a combination of both. References are provided to serve as a basis for further investigation. Although some selection bias may exist in the database because of its reliance on certain data sources, the database can be an asset in water resources planning and engineering. This paper is an overview of the CRREL Ice Jam Database and presents two applications of it.
LEACHATE LEAKAGE FROM LANDFILLS WITH MODERN LINER SYSTEMS1
Authors: Reddi Vinod J. , Scarlatos Panagiotis D.
Published: June 2007

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.
SIMULATION OF TEMPORAL CHANGES IN RAINFALL‐RUNOFF CHARACTERISTICS, COON CREEK BASIN, WISCONSIN1
Authors: Krug William R.
Published: June 2007

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 confidence level.
IDENTIFICATION AND ANALYSIS OF OUTDOOR RECREATION HABITATS: THE RECREATION HABITAT ANALYSIS METHOD1
Authors: Hamilton H. Roger.
Published: June 2007

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.
WATER QUALITY OF STORMWATER RUNOFF FROM TEN INDUSTRIAL SITES1
Authors: Line Daniel E. , Arnold Jon A. , Jennings Gregory D. , Wu Jy
Published: June 2007

ABSTRACT: This study was to designed to determine concentrations of selected metals, organic compounds, pesticides, and conventional pollutants in stormwater runoff from two North Carolina businesses in each of the following five general industrial groups: auto salvage, metal fabrication, scrap and recycling, vehicle maintenance, and wood preserving facilities. The sampling procedure involved collecting a first flush sample of runoff from a single storm event and both first flush and composite samples of runoff from three consecutive storm events. Analysis of samples collected during the first flush indicated that zinc and copper were the most common of the 13 metals included in the analysis. Additional analysis documented that several volatile organic, semi‐volatile organic, or pesticide compounds including acrolein, methylene chloride, xylenes, toluene, tetrachloroethylene, trichloroethylene, pentachlorophenol, and aldrin were also found in the first flush samples. Concentrations of aggregate organics, nitrogen, phosphorus, and sediment were determined in both first flush and three‐hour composite samples. Concentrations of pollutants in first flush samples were similar to those in corresponding composite samples.
PESTICIDES IN GROUND WATER: DO ATRAZINE METABOLITES MATTER?1
Authors: Liu Shiping , Yen Steven T , Kolpin Dana W.
Published: June 2007

ABSTRACT: Atrazine and atrazine‐residue (atrazine + two metabolites ‐ deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine‐residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.