bluuebunny/crossref_metadata_2025 huggingface dataset:
PERMEABILITY OF AIR AND IMMISCIBLE ORGANIC LIQUIDS IN POROUS MEDIA1
Authors: Gary J. W. , Simmons C. S. , McBride J. F.
Published: June 2007

ABSTRACT: The conductivity of air, mineral oil (relative viscosity 77), and a light nontoxic oil (relative viscosity 4.7) was measured in three porous media: a sand, loamy sand, and a silt loam. The measurements were made over a range of water contents for each porous medium. Small volumes of air were present as well as significant amounts of water during most of the oil conductivity measurements. The results were compared to two methods for calculating conductivities of immiscible fluids in water‐wet porous media. A new equation that accounts for swelling and for the gas slippage effect in very small pores was formulated for use with these methods The observed conductivities, spanning seven orders of magnitude, agree reasonably well with calculated values. Only three soil parameters are required to calculate the conductivities: (1) the saturated conductivity of water, (2) the saturated conductivity of the immiscible fluid of interest, and (3) a pore size index value that is obtained from an estimate from the water release curve of the porous material. Remediation of organic liquid spills is briefly discussed to illustrate the practical applications of gas phase conductivities, as well as those for immiscible organic liquid phases. It is concluded that, in light of spatial variation under field conditions, the method presented for calculating values of three‐phase conductivities will be useful in the management of immiscible organic liquid spills and leaks.
A PROPOSED MODIFICATION TO REGULATION OF LAKE OKEECHOBEE1
Authors: Trimble Paul J. , Marban Jorge A.
Published: June 2007

ABSTRACT: The current Lake Okeechobee regulation schedule is two feet higher than previous schedules that were in operation during the early 1970's. Its implementation was in response to prolonged periods of drought that occurred during the 1960's and early 1970's and the large increases in consumptive uses that were projected, and are presently occurring in south Florida. The additional storage provided by the schedule undoubtedly helped prevent more severe water shortages during the record setting 1980–1982 drought. However, two environmental concerns associated with the present schedule surfaced in recent years with the return to more normal rainfall conditions. First, the present schedule allows frequent high water conditions to exist in the lake that appear to be stressful to the unique littoral zone habitat of the lake. Second, the allowable buildup of storage prior to the dry season, combined with the large required decrease in storage prior to the hurricane (wet) season, contribute to the need for large regulation releases to tidewater. These large discharges have undesirable impacts on ecosystems of the downstream estuaries. This paper presents an alternative schedule that better meets the needs of the estuarine habitats without negatively impacting the other objectives of managing the lake.
CARBON CONTENT OF SEDIMENTS OF SMALL RESERVOIRS1
Authors: Ritchie Jerry C.
Published: June 2007

ABSTRACT: Carbon content was measured in sediments deposited in 58 small reservoirs across the United States. Reservoirs varied from 0.2 to 4000 km2 in surface area. The carbon content of sediment ranged from 0.3 to 5.6 percent, with a mean of 1.9 ± 1.1 percent. No significant differences between the soil and sediment carbon content were found using a paired t‐test or ANOVA. The carbon content of sediments in reservoirs was similar to the carbon content of surface soils (0–10 cm) in the watershed, except in watersheds with shrub or steppe (desert) vegetation. Based on the sediment accumulation rates measured in each reservoir, the calculated organic carbon accumulation rates among reservoirs ranged from 26 to 3700 gC m‐2yr‐1, with a mean of 675 ± 739 gC m‐2yr‐1. The carbon content and accumulation rates were highest in sediments from grassland watersheds. High variability was found in carbon content, carbon accumulation, and sediment accumulation rates due to individual watershed and reservoir characteristics rather than to any broad physiographic patterns. The carbon accumulation rates in these reservoir sediments indicate that reservoir sediments could be a significant sink for organic carbon.
LONGITUDINAL DISPERSION IN RWERS: A DEAD‐ZONE MODEL SOLUTION
Authors: Yu Yun‐Sheng , Wenzhi Liu
Published: June 2007

ABSTRACT: The longitudinal dispersion of tracer material in rivers is simulated by a dead‐zone model that involves two coupled differential equations. For an instantaneous injection of tracer material, the problem is solved by the Laplace. Transform and numerical inversion to obtain the time‐concentration curve at any sampling station. The optimal values of the model parameters are estimated from field measurements. Applications of the model to three different rivers generally show that the model reproduces the longitudinal dispersion characteristics in natural streams with sufficient accuracy.
A MANGANESE OXIDATION MODEL FOR RIVERS1
Authors: Hess Glen W. , Kim Byung R. , Roberts Philip J.W.
Published: June 2007

ABSTRACT: The presence of manganese in natural waters (>0.05 mg/L) degrades water‐supply quality. A model was devised to predict the variation of manganese concentrations in river water released from an impoundment with the distance downstream. The model is one‐dimensional and was calibrated using dissolved oxygen, biochemical oxygen demand, pH, manganese, and hydraulic data collected in the Duck River, Tennessee. The results indicated that the model can predict manganese levels under various conditions. The model was then applied to the Chattahoochee River, Georgia. Discrepancies between observed and predicted may be due to inadequate pH data, precipitation of sediment particles, unsteady flow conditions in the Chattahoochee River, inaccurate rate expressions for the low pH conditions, or their combinations.
TRANSITIONS IN MIDWESTERN GROUND WATER LAW1
Authors: Bowman Jean A. , Clark Gary R.
Published: June 2007

ABSTRACT: The evolution of ground‐water law in eight states in the Midwest (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin) is examined, and a review of transitions in ground‐water doctrines is presented. Two underlying themes in changing ground‐water management are communicated. First, ground‐water law is evolving from private property rules of capture based on the absolute ownership doctrines to rules requiring conservation and sharing of ground water as a public resource. Second, in both courts and state legislatures, a proactive role of ground‐water management is emerging, again, with an emphasis on sharing. Both of these trends are apparent in the Midwest. In the last decade midwestern states have (1) seen significant shifts in court decisions on ground‐water use with greater recognition of the reciprocal or mutually dependent nature of ground‐water rights, and (2) seen increased legislative development of comprehensive ground‐water management statutes that emphasize the reciprocal liabilities of ground‐water use. These trends are examined and ground‐water management programs discussed for eight states in the Midwest.
COMBINATION OF RADAR AND GAUGE DATA IN A RAINFALL ARCHIVE SYSTEM1
Authors: Mylne M.F.
Published: June 2007

ABSTRACT: Near real time daily rainfall estimates for the UK are available from three sources: a sparse network of gauges, radar data, or radar data adjusted by the sparse gauges. The PARAGON rainfall archive system, which has been developed by the UK Meteorological Office, is able to produce these estimates in near real time on a 5 km grid. The ability of these estimates to reproduce the 5 km grid point field derived later from a dense network of gauges is compared using case studies. Five techniques have been used to assess the relative quality of the various estimates. There is general agreement between the results of the various techniques. For the London radar there are examples of days when the rainfall estimate was improved by incorporating radar data; conversely, there are days when the radar data make it worse. Overall little evidence was found to suggest that adjusted radar data are consistently markedly better than gauge estimates. Discriminate use of radar data is recommended.
ESTIMATING EVAPORATION FROM UTAH'S GREAT SALT LAKE USING THERMAL INFRARED SATELLITE IMAGERY1
Authors: Miller Woodruff , Millis Eric
Published: June 2007

ABSTRACT: Water surface temperatures can be obtained from satellite thermal remote sensing. Landsat and other satellites sense emitted thermal infrared radiation on a regular basis over much of the earth's surface. Evaporation is accomplished by the net transport of mass from the water surface to the atmosphere. The evaporative transfer predominantly determines the water surface temperature. Hence, there should be good correlations between evaporation and surface temperatures. Previous investigations on Utah Lake with satellite‐derived temperatures and pan‐ and model‐derived evaporation values have produced good correlations. However, more study was required with additional satellite data and evaporation measurements for saltwater conditions. The applicability of this method for estimating evaporation on Utah's Great Salt Lake was of particular interest at this time because of the unprecedented rise of this terminal lake. Satellite thermal data and evaporation data from four different years were obtained for the Great Salt Lake and the surrounding region. More than 350 correlation and linear regression analyses were performed on the temperature and evaporation data. The lake salt concentrations were also factored into the analyses in several different ways. The correlation results were generally very good and a methodology for using satellite‐derived water surface temperatures along with salt concentrations was developed to estimate evaporation.
MODELING OF LEAKAGE THROUGH CRACKED CLAY LINERS ‐I: STATE OF THE ART1
Authors: Miller Carol J. , Mishra Manoj
Published: June 2007

ABSTRACT: The existence and importance of macro‐pores to the containment efficiency of cover clay liners at waste landfills is documented. Macro‐pores exist as voids, or cracks, and act to increase the volume and rate of leakage through cover liners. Existing numerical models used to simulate flow through clay liners are shown to neglect the macro‐pore aspect of the problem. Current theories of macro‐pore flow developed from related areas of research are presented, and applications to the landfill liner problem are considered.
DEFINING REGIONAL POPULATIONS OF LAKES FOR THE ASSESSMENT OF SURFACE WATER QUALITY1
Authors: Johnson Colleen Burch , Sullivan T.J. , Buck D.J.
Published: June 2007

ABSTRACT: Topographic maps are commonly used to define populations of lakes in regional surveys of surface water quality. To illustrate the effect of different maps on that process, we compared the lakes represented on the 1:250,000‐scale maps used for the Northeast Region of the Eastern Lake Survey—Phase I (ELS‐I) to the lakes on a sample of large‐scale maps (1:24,000 or 1:62,500). Lake areas at or near the lower limit of representation delimited “smallest‐lake” values for the compared 1:250,000‐scale maps. The regional median for these values was 4.5 hectares (ha) and ranged from 0.6 to 24.8 ha. Lake representation is influenced by cartographic limitations such as map scale, age, and complexity as well as the inherent variability of waterbodies (e.g., water level fluctuations or the creation of reservoirs, beaver impoundments, and oxbows). The total number of lakes on large‐scale maps increased markedly as lake area decreased. Approximately 15,700 of the estimated 29,000 lakes in the EPA's Northeast Region were 1 to 4 ha in area. Because maps affect the size distribution of lakes included in a regional survey and because lake areas are thought to modify lake chemistry, maps ultimately affect the estimates of regional surface water quality.
KALMAN FILTER CALCULATION OF SAMPLING FREQUENCY WHEN DETERMINING ANNUAL MEAN SOLUTE CONCENTRATIONS
Authors: Stednick J.D. , Roig L.C.
Published: June 2007

ABSTRACT: A linear filter (Kalman filter) technique was used with a Streamflow‐concentration model the minimize surface water quality sampling frequencies when determining annual mean solute concentrations with a predetermined allowable error. The Kalman filter technique used the stream discharge interval as a replacement for the more commonly used time interval. Using filter computations, the measurement error variance was minimized within the sample size constraints. The Kalman filter application proposed here is applicable only under several conditions including: monitoring is solely to estimate annual mean concentration; discharge measurement errors are negligible; the Streamflow‐concentration model is valid; and monthly samples reflect the total variance of the solute in question.
WATER QUALITY AND MACROINVERTEBRATE POPULATIONS BEFORE AND AFTER A HAZARDOUS WASTE CLEANUP1
Authors: Siewert Horst F. , Miller Carla J. , Torke Byron G.
Published: June 2007

ABSTRACT: Water samples and macroinvertebrates were collected from Finley Creek, Indiana, both before and two years after the cleanup of a nearby hazardous waste site. Water quality constituents were compared between years. Below the disposal site higher concentrations of constituents were found before and after the cleanup. However, two years after the cleanup, an improvement of water quality was observed. Total dissolved solids decreased by 52% and macroinvertebrate taxa increased by 44%.
ESTIMATION OF RECHARGE FROM A RESERVOIR USING TWO WATER BUDGET MODELS1
Authors: Al‐Muttair Fouad F. , Al‐Turbak Abdulaziz S.
Published: June 2007

ABSTRACT: Reservoir water levels, observation well data, and meteorological parameters were collected at a recharge dam site in Central Saudi Arabia. This data, along with other information on the reservoir and the underlying aquifer, were used to estimate the amounts of recharge through the reservoir bed by applying two water budget models. The first is a water budget model for the reservoir only, while the second is for an aquifer reach extending upstream and downstream from the reservoir. The results of the two approaches were discussed and compared.
A PROGRAM TO CALCULATE CHANNEL SCOUR AND FILL1
Authors: Noel James R. , Sidle Roy C.
Published: June 2007

ABSTRACT: A computer program written in BASIC calculates net changes in stream channel cross‐sections. Calculations are based on dividing the channel cross‐section into discrete regions of scour and fill. Internal boundaries of these regions (along the x‐axis of the cross‐section) are determined by the location of vertical depth measurements taken at two distinct times. The right and left boundaries of the cross‐section can be specified so that scour or fill can be calculated for any portion of the profile desired.
ESTIMATING A CARBON/CHLOROPHYLL RATIO IN NANNOPLANKTON (CRETEIL LAKE, S‐E PARIS, FRANCE)1
Authors: Gamier J. , Blanc P. , Benest D.
Published: June 2007

ABSTRACT: The phytoplankton biomass of the Créteil Lake was characterized through 47 paired measurements of particulate organic carbon and chlorophyll. When determining the tranfers of organic carbon in the lake, the need to convert the phytoplankton biomass into carbon units led to the estimation of a carbon to chlorophyll ratio using regression analyses. An average C:Chl ratio of 80 was found. C:Chl has been found to be highly variable but the value commonly used is C:Chl = 40. In Créteil Lake, the high C:Chl value would characterize the nannoplankton that dominated in the lake. No general conversion factor apparently exists for natural populations; thus, more studies may be necessary for a better knowledge of the carbon budget in lakes.
EFFECTS OF SIMULATED CANOPY COVER AND ANIMAL DISTURBANCES ON RILL AND INTERRILL EROSION1
Authors: Savabi M.R. , Gifford G.F.
Published: June 2007

ABSTRACT: A rainfall simulator was used on runoff plots to study the effects of simulated canopy cover, trampling disturbance, and soil type on nil and interrill erosion. Sandy loam soil was more erodible than clay loam soil. Furthermore, the simulated canopy cover signffi‐Soilfactorsrelatedtonil cantly influenced nil and interrill erosion. The effect of trampling on rill and interrill erosion varied with soil type (clay loam versus sandy loam) and erosion type (nh versus interrill erosion). On large plots, where both nil and internill erosion were involved, 30 percent trampling significantly increased soil loss. However, on small plots, 30 percent trampling significantly reduced interrill erosion.
THE VALUE OF STREAMFLOW FORECASTING IN RESERVOIR OPERATION1
Authors: Georgakakos Arts P.
Published: June 2007

ABSTRACT: The value of streamflow forecasts in reservoir operation depends on a number of factors and may vary considerably. Assessment of forecast benefits is presented here for three specific systems. Statistical streamflow models of increasing forecasting ability are coupled with a recently developed stochastic control method in extensive simulation experiments. The performance of the system is statisticafly evaluated with regard to energy generation and flood and drought prevention. The results indicate that forecast benefits are system specific and may range from quite substantial to fairly minimal.
FLOW PERSISTENCE AS A MODIFIER OF SEASONAL RUNOFF PATTERNS1
Authors: Snyder W.M. , Thomas A.W. , Dillard A.L.
Published: June 2007

ABSTRACT: The effect of flow persistence on seasonal patterns of watershed runoff was modeled by using runoff of the immediate antecedent month as an index. Monthly runoff was expressed as a function of monthly rainfall, season of the year, and runoff of the antecedent month. The three independent variables were expressed functionally as sliding polynomials, thus producing a piece‐wise, form‐free, three‐dimensional causative structure. A model form allowing complete interactivity of the three independent variables could not be optimized because of insufficient data with high values of both antecedent runoff and monthly rainfall. A model with reduced interactivity was successfully optimized. Data sets from five watersheds ranging from 0.14 to 398 square miles were analyzed. Results were presented as a series of contour maps that showed contours of monthly runoff in the data space of season and monthly rain. In the series of maps, the patterns of the runoff contours changed with changing values of antecedent runoff. During the wet season of the year the contours changed significantly with antecedent runoff, but changes in the dry season were minimal. The quantitative change of runoff was more readily portrayed with cross‐sections through the contoured surfaces.
GENERATION OF SYNTHETIC AND MISSING CLIMATIC DATA FOR PUERTO RICO1
Authors: Shih S.F. , Cheng K.S.
Published: June 2007

ABSTRACT: Climatic data such as temperature, solar radiation, relative humidity, and wind speed have been widely used to estimate evapotranspiration. Moat of the solar radiation data and portions of the relative humidity data are either not available or missing from the records in Puerto Rico. Depending upon the availability and data characteristics of records, three methods (including a regression technique, an averaging of historical data, and a regional average) were used to generate missing data, and a time series analysis was used to synthesize a series of climatic data. The limitations and applicability of each method are discussed. The results showed that the time series analysis method can be successfully used to synthesize a series of monthly solar radiations for several stations. The regression technique and the regional average can be successfully applied to generate missing monthly solar radiation data. The regression technique and the averaging of historical data have been satisfactorily used to interpolate missing monthly relative humidity. The explained variance (R2) varied from 0.68 to 0.88, which are both significant at the 0.05 level of significance.
MODELING THE EFFECT OF BRUSH CONTROL ON RANGELAND WATER YIELD1
Authors: Savabi M.R. , Arnold J.G. , Richardson C.W. , Krishna J. L.
Published: June 2007

ABSTRACT: With the increase in water demand in Texas, attention has turned to improving water yield by brush control on rangeland watersheds. Several hydrologic models have been developed for either farmland or rangeland. However, none of the models were specifically developed to assess the impact of brush control on rangeland water yield. Yet, modeling the impact of brush control on water yield needs to be considered if alternative techniques are to be compared. Two models, Ekalaka Rangeland Hydrology and Yield Model (ERHYM‐II) and Simulator for Water Resources on Rural Basins (SWRRB) were selected. The Soil Conservation Service curve number (SCS‐CN) method is used in both models to predict surface runoff from each rainfall event. The major differences between the ERHYM‐II and SWRRB models are the evapotranspiration, soil water routing, and plant growth components. The models were evaluated on brush‐dominated and chemically and mechanically brush‐controlled range watersheds in Texas. Results indicated that both models were capable of simulating soil water and water yield from brush dominated and chemically brush‐controlled range watersheds. The models were not able to predict water yield from the mechanically brush‐controlled (root plowed) watershed with acceptable accuracy. The depressions that were caused by root plowing stored surface runoff and reduced water yield from the watershed. Information about the size of depressions was not available for further model evaluation.
A STOCHASTIC MODEL TO EVALUATE RIPARIAN IRRIGATION EXPANSION IN THE EASTERN UNITED STATES1
Authors: Bosch Darrell , Mustafa Golam
Published: June 2007

ABSTRACT: Irrigation has expanded in parts of the eastern United States. In some areas, the adjoining surface (riparian) water is the most economical source of irrigation water. Expanded demand for riparian water may lead to conflict among irrigators and other streamflow users. Accurate information on the potential for and impacts of riparian irrigation expansion is needed to decide if control of such expansion is necessary. In this study, a stochastic economic model to evaluate the impacts of potential irrigation expansion is presented. The model considers the soil, location, and land use characteristics of individual sites, as well as weather and streamflow patterns. The application of the model to an eastern Virginia watershed indicates that, with maximum potential expansion, water availability becomes limited and yields will be reduced in some years. As a result, the expected net returns from irrigation and the probability of breaking even on the investment are reduced substantially. The results suggest the need to consider regulation of surface water allocation for irrigation development in riparian watersheds.
CONFLICT ANALYSIS AND MANAGEMENT ALTERNATWE FOR THE MANAYLJNK CANAL1
Authors: Chadderton Ronald A.
Published: June 2007

ABSTRACT: The solution of a water resource allocation problem by an alternative social arrangement is presented. Classical Austrian economic theory and the “new resources economics” provide both theoretical and practical evidence to support the development of well‐defined, private property rights to the water resource in question. A conflict analysis demonstrates that management of the Manayunk Canal by a firm would reconcile existing confrontations through compromise use of the water resource. Benefit and cost calculations show that a compromise among industrial and recreational interests, currently competing in the political arena, would increase social benefits.
VALUING IRRIGATION WATER IN PUNJAB PROVINCE, PAKISTAN: A LINEAR PROGRAMMING APPROACH1
Authors: Chaudhry Muhammad Aslam , Young Robert A.
Published: June 2007

ABSTRACT: Linear programming models of a representative farm in a district of Pakistan's Punjab Province are formulated for the purpose of estimating the value of irrigation water. The models provide for choices among several irrigation levels for each potential crop. Solutions of the model for several water supply situations provide the basis for approximating the total, average, and marginal values of irrigation water. Prices for important crops in Pakistan are controlled at levels below their levels elsewhere in the world, so models are specified for both financial (domestic price) and economic (world price) scenarios. The value of water to society (its economic value) is high relative to the costs of some generally available water‐augmenting investments, while financial values, which measure water management and allocation incentives faced by farmers, are less than the corresponding economic values. At current water supply levels, incremental returns to added water estimated from the economic model would justify investments in water‐saving or water‐augmenting technologies, while such a decision would be barely attractive assuming financial prices. While present government commodity price policies may serve to protect low‐income and non‐farm members of the population, they also inhibit farmer investments to increase the productivity of scarce irrigation water.
WATER SUPPLY IMPACTS OF NUCLEAR FALL1
Authors: Hobbs Benjamin F. , Luo Yongshou , Maciejowski M. E. , Chester Conrad V.
Published: June 2007

ABSTRACT: “Nuclear winter,” more properly called “nuclear fall,” could be caused by injection of large amounts of dust into the atmosphere. Besides causing a decrease in temperature, it could be accompanied by “nuclear drought,” a catastrophic decrease in precipitation. Dry land agriculture would then be impossible, and municipal, industrial, and irrigation water supplies would be diminished. It has been argued that nuclear winter/fall poses a much greater threat to human survival than do fall out or the direct impacts of a conflict. However, this does not appear to be true, at least for the U.S. Even under the unprecedented drought that could result from nuclear fall, water supplies would be available for many essential activities. For the most part, ground water supplies would be relatively invulnerable to nuclear drought, and adequate surface supplies would be available for potable uses. This assumes that conveyance facilities and power supplies survive a conflict largely intact or can be repaired.
ASSESSMENT OF STORMWATER RUNOFF FOR RECYCLE IN COOLING TOWERS AT KSC, FLORIDA1
Authors: Dierberg Forrest E. , Jones Krista L.
Published: June 2007

ABSTRACT: In addition to measuring the quantity of stormwater runoff generated during ten rainfall events from the Vehicle Assembly Building (VAB) area of Kennedy Space Center (KSC), historical rainfall records were also used for determining the feasibility of implementing a program of stormwater recycling to air conditioning cooling towers. It was projected that 0.182 million gallons per day (MGD) of runoff would be generated from the VAR area during a year of average rainfall (48 inches); only 0.117 MGD is required for coolant makeup water in the VAR area. Due to the seasonal variations in rainfall, stormwater recycling may not always meet all the cooling water demands.
SPREADSHEET WATERSHED MODELING FOR NONPOINT‐SOURCE POLLUTION MANAGEMENT IN A WISCONSIN BASIN1
Authors: Walker John F. , Pickard Susan A. , Sonzogni William C.
Published: June 2007

ABSTRACT: Although several sophisticated nonpoint pollution models exist, few are available that are easy to use, cover a variety of conditions, and integrate a wide range of information to allow managers and planners to assess different control strategies. Here, a straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit‐area loadings, can be used to estimate nonpoint‐source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost‐effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.
EDUCATING THE RURAL PUBLIC ABOUT SAFE DRINKING WATER1
Authors: Mancl Karen , Sharpe William , Makuch Joseph
Published: June 2007

ABSTRACT: From 1984 to 1987, the Penn State Cooperative Extension Service conducted 40 safe drinking water clinics for more than 3000 rural homeowners. The clinics were developed to provide homeowners and farmers with information on managing their private water supplies. Four of the clinics were evaluated using a mail survey. By using a four part mailing, response rates of 63 to 77 percent were achieved. Based on the evaluation results of the four clinics, 11 of the 14 objectives dealing with information value, knowledge gained, and actions taken were met.
MANAGEMENT AND POLICY EFFECTS ON POTENTIAL GROUNDWATER CONTAMINATION FROM DAIRY WASTE1
Authors: Heatwole C. D. , Diebel P. L. , Halstead J. M.
Published: June 2007

ABSTRACT: A combined economic and water quality modeling framework was used to evaluate impacts of alternative policies and management practices on reducing nitrate movement to groundwater for dairy farms in Rockingham County, Virginia. The analysis considers three on‐farm manure storage options, cost‐sharing programs for purchasing manure storage facilities, restrictions on nitrogen application rates, and a tax on commercial fertilizer. The CREAMS model was used to estimate nitrate leaching from the crop root zone for various nutrient (and manure) management practices, based on timing and rate of manure and fertilizer applications. The mixed‐integer programming economic model considers water quality, policy, and economic constraints in comparing the profitability of alternative cropping and nutrient management systems that reduce groundwater contamination potential. The study provides both the environmental and economic effects of better management of dairy waste.
POLICY IMPACTS ON AGRICULTURAL IRRIGATION ELECTRICITY DEMAND IN THE COLUMBIA BASIN1
Authors: Martin Michael , Cox Linda , Nakamoto Stuart , Halloran John
Published: June 2007

ABSTRACT: Accurately estimating the price elasticity of demand for irrigation electricity is important to major electricity suppliers such as the Bonneville Power Administration (BPA) of the Pacific Northwest. The BPA has a revenue maximization objective, and the elasticity of demand is central to its rate setting process. Several studies have attempted to estimate demand for irrigation electricity, but none has explicitly included federal agricultural policy and program variables. Tins paper discusses how agricultural programs may influence farmers irrigation decisions and thus their demand for irrigation electricity. It suggests that existing programs serve to make farmers more responsive to electricity rate increases than would otherwise be the case. Thus, studies that fail to include them may underestimate the responsiveness of farmers to electricity rate increases.
EVALUATION OF BEST MANAGEMENT PRACTICES FOR CONTROLLING NONPOINT POLLUTION FROM SILVICULTURAL OPERATIONS1
Authors: Lynch James A. , Corbett Edward S.
Published: June 2007

ABSTRACT:Fifteen years of streamflow and water quality data were evaluated to determine the effectiveness of Best Management Practices (BMP's) in controlling nonpoint source pollution from an 110. acre commercial clearcut located in the Ridge and Valley Province of central Pennsylvania. The analyses addressed both short‐ and long‐term changes in the physical and chemical properties and the hydro‐logic regime of the stream draining this 257‐acre watershed. Overall, the BMP's employed on this commercial clearcut were very effective in preventing serious deterioration of stream quality as a result of forest harvesting. Although statistically significant increases in nitrate and potassium concentrations and temperature and turbidity levels were measured the first two years following harvesting, the increases were relatively small and, with the exception of turbidity, within drinking water standards. Nevertheless, such increases may violate EPA's anti‐degradation policy. Nitrate and potassium concentrations and turbidity levels remained above pre‐harvesting levels for as long as nine years following harvesting. Clearcutting also significantly increased water yield, which in turn initially lowered the concentrations of most solutes because of dilution. Increased water yields returned to pro‐harvesting levels within four years as a result of rapid regrowth. The export of some ions increased; however, the increased export appeared to be insufficient to affect site fertility. Implementation of periodic post‐harvest inspections of harvested areas, increasing the width of the buffer zone, and utilizing buffer zones on all perennial and intermittent channels would reduce further impacts of silvi‐cultural activities on water quality.
NUTRIENT DISTRIBUTION AND VARIABILITY IN THE CHARLOTTE HARBOR ESTUARINE SYSTEM, FLORIDA1
Authors: McPherson Benjamin F. , Miller Ronald L.
Published: June 2007

ABSTRACT: The sources and distribution of nutrients in the Charlotte Harbor estuarine system were evaluated using nutrient dilution curve models. Except for ammonia, nutrient concentrations were highest and most variable in the rivers, and generally decreased with increasing salinity. Observed and theoretical dilution curves for phosphorus were generally in close agreement, which suggests conservative behavior. Phosphorus concentrations sagged below a straight line because phosphorus‐rich water from the upper Peace River basin was diluted by tributaries in the lower basin. The concentrations of dissolved silica appeared to be conservative on some occasions. On other occasions, dissolved silica appeared to be removed at low salimties or released at higher salinities. Concentrations of ammonia were highly variable along the salinity gradient, presumably because of variations in ammonia regeneration and uptake. Concentrations of nitrite plus nitrate were well below conservative dilution curves, probably due to phy‐toplankton uptake. At salinities greater than 20%, nitrite plus nitrate concentrations were usually at or below the detection limit and may limit phytoplankton productivity. Projected increased nitrogen loadings from urban development in the basin would favor undesirable increases in phytoplankton and benthic algal growth in waters where sufficient light is available.
TILE RATIONALE FOR OHIO'S DETERGENT PHOSPHORUS BAN1
Authors: Hartig John H. , Trautrim Christine , Dolan David M. , Rathke David E.
Published: June 2007

ABSTRACT: Ohio signed into law a detergent phosphorus ban on March 26, 1988. This law limits the elemental phosphorus content of household laundry detergents to 0.5 percent in all 35 Lake Erie counties in Ohio by 1990. Ohio's detergent phosphorus ban will help non‐compliant municipal wastewater treatment plants achieve compliance with the 1 mg/L effluent phosphorus standard. By limiting the phosphorus content of household laundry detergents, Ohio will also benefit from less phosphorus entering surface waters from combined sewer overflows, communities with treatment plant bypasses, and riparian homes with septic tanks. This is important because most of the phosphorus in laundry detergents is in the bioavailable form and Ohio's Lake Erie shoreline is particularly sensitive to Cladophora problems. When viewed in conjunction with reduced chemical costs for phosphorus removal and savings in sludge disposal costs, Ohio's detergent phosphorus ban is a pragmatic component of an international phosphorus management strategy to protect the Great Lakes.
REELFOOT LAKE SEDIMENTATION RATES AND SOURCES1
Authors: McIntyre Sherwood C. , Naney James W.
Published: June 2007

ABSTRACT: The three basins of Reelfoot Lake, which is located in northwestern Tennessee, were investigated using the Cs‐137 tracer technique to determine rates of sediment deposition and to estimate the time before the basins will fill with sediment. Blue Basin, the largest of the three basins with 2922 ha, had an average annual sedimentation rate of 0.9 cm/yr from 1984 to 1984. The basin will become too shallow for most boating and recreational activities in about 200 years. Buck Basin, the central basin with 774 ha, had an average annual sedimentation rate of 1.1 cm/yr and will become too shallow for most recreational uses in about 100 years. Upper Blue Basin, the most upstream and smallest basin with 439 ha, had an average annual sedimentation rate of 1.7 cm/yr and will become too shallow for most recreational uses in about 60 years.

Two important sources of sediment to Reelfoot Lake are erosion from a large number of soybean fields and channelization of many of the streams that flow into the lake. Changes in land management that would reduce erosion could increase the time the lake would remain usable for recreational activities.
COMPUTER‐AIDED PLANNING FOR MULTIPLE‐PURPOSE RESERVOIR OPERATING POLICIES1
Authors: Johnson Lynn E.
Published: June 2007

ABSTRACT: Computer‐aided planning (CAP) for multiple‐purpose reservoir operations involves use of state‐of‐the‐art simulation and optimization methods, color graphic displays, and interactive computing interfaces. These technologies were integrated into a coherent system that has user‐friendly interfaces to help the process of communicating reservoir system operations, solicit planning participant preferences and valuation judgments, and provide understandable feedback of system performance. The CAP system was imbedded in a comprehensive public involvement program that paralleled the reservoir operating policy modeling process, as part of multipurpose reservoir operations planning on the Great Plains Reservoirs in Colorado. Experience with the approach indicates the involved publics can quickly learn of reservoir system limitations and opportunities, and can indeed participate in the operations planning process.
WATER AUCTIONS AS AN ALLOCATION MECHANISM IN VICTORIA, AUSTRALIA1
Authors: Simon Benjamin , Anderson David
Published: June 2007

ABSTRACT: During recent years many countries have moved to rationalize the management of state owned or state controlled resources. In Victoria, Australia, water, in particular, has received a great deal of attention. Subsidies to construct, operate, and rehabilitate irrigation facilities have been reduced, and there have been numerous consolidations of small water supply authorities to achieve economies of scale. In addition, Victoria has taken the unusual step of using auctions to allocate new irrigation water entitlements.

The six water auctions that took place during 1988 and early 1989 were perceived as an efficient and equitable mechanism to allocate limited water supplies to their highest value use. While the agricultural areas where the different auctions occurred were similar, there was substantial variation in the prices paid, which reflects varying demands for additional irrigation water.

This paper will discuss the following topics: the auction process used and the results of the auctions, the efficiency of the auction procedures, and the factors influencing the demand for additional irrigation water in the different auctions. In addition, the implications of using auctions to allocate water supplies for future water management in Victoria will be discussed.
STREAM‐CHANNEL INCISION FOLLOWING DRAINAGE‐BASIN URBANIZATION1
Authors: Booth Derek B.
Published: June 2007

ABSTRACT: Urbanization of a drainage basin results in pervasive hydrologic changes that in turn initiate long‐term changes in stream channels. Increases in peak discharges and in durations of high flows result in either quasi‐equilibrium channel expansion, where cross‐section area increases in near‐proportion to the discharge increase, or catastrophic channel incision, where changes occur far out of proportion to the discharge increases that initiated them. Field data and hydrologic modeling of rapidly urbanizing basins in King County, Washington, define conditions of flow, topography, geology, and channel roughness that identify streams susceptible to incision. Channel slope and geologic material are particularly critical; thus simple map overlays, nearly irrespective of contributing drainage area, provide a valuable planning tool for identification of susceptible terrain. Where such conditions exist, basal shear stress provides a quantifiable parameter for predicting likely problems, although knickpoints are typical in such settings and confound simple calculation of sediment‐transport rates. Where urbanization proceeds in such areas, effective mitigation of the incision hazards requires a degree of stormwater control far in excess of standards typically applied to present development activity.
HYDROLOGIC AND HYDRAULIC RESEARCH IN MOUNTAIN RWERS1
Authors: Jarrett Robert D.
Published: June 2007

ABSTRACT: Although our current (1990) knowledge of hydrologic and hydraulic processes is based on many years of study, there are river environments where these processes are complex and poorly understood. One of these environments is in mountainous areas, which cover about 25 percent of the United States. Use of conventional hydrologic and hydraulic techniques in mountain‐river environments may produce erroneous results and interpretations in a wide spectrum of water‐resources investigations. An ongoing U.S. Geological Survey research project is being conducted to improve the understanding of hydrologic and hydraulic processes of mountainous areas and to improve the results of subsequent hydrologic investigations. Future hydrologic and hydraulic research needs in mountainous areas are identified.
TARGETING REMEDIAL MEASURES TO CONTROL NONPOINT SOURCE POLLUTION1
Authors: Dickinson W. T. , Rudra R. P. , Wall G. J.
Published: June 2007

ABSTRACT: The watershed model GAMES is used for the evaluation of a targeting approach to control fluvial sedimentation arising from soil erosion in agricultural areas. The data considered for the analysis consists of output from the application of the model to existing and hypothetical soil and crop management systems in two small watersheds of southern Ontario, one in the rolling uplands and the other in a very flat lowland area. The model output includes estimates of spring sediment yield from field‐size cells to the stream outlet for existing agricultural management conditions, and estimates of sediment yield resulting from the successive implementation of two levels of soil erosion controls under four remedial measures strategies. The results reveal that, for the rolling upland watershed exhibiting a wide range of soil erosion and sediment yield rates, targeted control programs can be expected to provide an extremely effective approach to sediment control. For flat lowland watersheds, exhibiting relatively uniform soil erosion and sediment yield rates, the strategy of targeting controls may be somewhat more effective than a random approach to control, but not as efficient as in the case of watersheds in more rolling terrain. It is evident from the study that a screening model such as GAMES provides a very useful tool for the planning and evaluation of erosion and sediment control programs.
FATE OF NITROGEN AND PHOSPHORUS ENTERING A GULF COAST FRESHWATER LAKE: A CASE STUDY1
Authors: DeLaune R. D. , Lindau C. W. , Knox R. S. , Smith C. J.
Published: June 2007

ABSTRACT: Nitrogen and P fluxes, transformations and water quality functions of Lake Verret (a coastal Louisiana freshwater lake), were quantified. Ortho‐P, total‐P, NH4+‐N NO3 ‐N and TKN in surface water collected from streams feeding Lake Verret averaged 104, 340, 59, 185, and 1,060 mg 1−1, respectively. Lake Verret surface water concentrations of ortho‐P, total‐P, NH+‐N, NO3−‐N and TKN averaged 66, 191, 36, 66, and 1,292 μg 1−1. The higher N and P concentrations were located in areas of the lake receiving drainage. Nitrification and denitrification processes were significant in removing appreciable inorganic N from the system. In situ denitrification rates determined from acetylene inhibition techniques show the lake removes 560 mg N m−2 yr−1. Laboratory investigations using sediment receiving 450 μg NH+4‐N (N‐15 labeled) showed that the lake has the potential to remove up to 12.8 g N m−2 yr−1. Equilibrium studies of P exchanges between the sediment and water column established the potential or adsorption capacity of bottom sediment in removing P from the overlying water. Lake Verret sediment was found to adsorb P from the water column at concentrations above 50 μg P 1−1 and the adsorption rates were as great as 300 μg P cm−2 day−1 Using the 137C s dating techniques, approximately 18 g N m−2 yr−1 and 1.2 g P m−2 yr−1 were removed from the system via sedimentation. Presently elevated nutrient levels are found only in the upper reaches of the lake receiving nutrient input from runoff from streams draining adjacent agricultural areas. Nitrification, denitrification, and adsorption processes at the sediment water interface over a relatively short distance reduces the N and P levels in the water column. However, if the lake receives additional nutrient loading, elevated levels will likely cover a larger portion of the lake, further reducing water quality in the lake.
AN ADDITIONAL ANALYSIS OF PEAK‐VOLUME RELATIONS AND STANDARDIZATION PROCEDURES1
Authors: Molfino M. E. , Cruise J. F.
Published: June 2007

ABSTRACT: Much has been written about the linear relationship in log space between the runoff volume of a hydrograph and the peak discharge. Three versions of this relation (an original and two standardizations) have been presented and recommended by various authors. In this paper, the standardized equations are compared to the original relationship and the behavior of the coefficient of determination (r2) in each case is discussed. It is shown that the r2 of the standardized equations is increased or decreased relative to that of the original relation based upon the magnitude of the original slope. Further implications of these relationships are discussed and demonstrated using a data base of 90 watersheds and over 1,200 separate flood hydrographs.
CHEMISTRY RESPONSE OF TWO FORESTED WATERSHEDS TO ACID ATMOSPHERIC DEPOSITION1
Authors: Kress M. W. , Baker R. , Ursic S. J.
Published: June 2007

ABSTRACT: The deposition and chemistry of precipitation were estimated for one year in two forest ecosystems in the South‐Central United States. Precipitation, throughfall, litter leachate, and soil leachate were analyzed for a small catchment of pine‐hardwoods in southeastern Oklahoma and for a catchment of loblolly pines (Pinus taeda L.) in northern Mississippi. In the pine‐hardwood forest, 98 percent of the acid deposition was neutralized, 50 percent in the forest canopy, and 48 percent in the forest floor. In the pine forest, 75 percent of the acid deposition was neutralized, all in the forest floor. The pine‐hardwood ecosystem accumulated sulfate, nitrate, and ammonia ions, and lost base cations. During seasons of deficient precipitation, dry deposition appeared to enrich the concentrations of hydrogen, nitrate, sulfate, and ammonia ions in throughfall samples at both locations.
APPLICATION OF THE DR3M WATERSHED MODEL ON A SMALL URBAN BASIN1
Authors: Thomas Richard P.
Published: June 2007

ABSTRACT: Data collected at a 79‐acre urban watershed in Albuquerque, New Mexico, were used to calibrate and verify the Distributed Routing Rainfall‐Runoff Model, a parametric watershed model. Standard errors of estimate for the 38 calibration storms were 33 percent and 38 percent, respectively, for volumes and peaks; and for the 46 verification storms were 29 percent and 37 percent, respectively, for volumes and peaks. Correlation coefficients for peaks were 0.8 and 0.95, respectively, for calibration and verification storms.