bluuebunny/crossref_metadata_2025 huggingface dataset:
DEVELOPMENT AND TESTING OF A SNOWMELT‐RUNOFF FORECASTING TECHNIQUE1
Authors: Rango Albert , van Katwijk Victor
Published: June 2007

ABSTRACT: The snowmelt‐runoff model (SRM) was used to produce accurate simulations of streamfiow during the snowmelt period (April‐September) for ten years on the Rio Grande Basin (3419 km2) near Del Norte, Colorado, U.S.A. In order to use SRM in the forecast situation, it was necessary to develop a family of snow cover depletion curves for each elevation zone based on accumulated snow water equivalent on April 1. Selection of an appropriate curve for a particular year from snow course measurements allows input of the daily snow cover extent to SRM for forecast purposes. Data from three years (1980, 1981, and 1985) were used as a quasi‐forecast test of the procedure. In these years forecasted snow cover extent data were input to SRM, but observed temperature and precipitation data were used. The resulting six‐month hydrographs were very similar to the hydrographs in the ten simulation years previously tested based on comparisons of performance evaluation criteria. Based on this result, the Soil Conservation Service (SCS) requested SRM forecasts for 1987 on the Rio Grande. Using the same procedure but with SCS estimated temperature and precipi‐tation data, SRM produced a forecast hydrograph that had a r2= 0.82 and difference in seasonal volume of 4.4 percent. To approximate actual operational conditions, SRM computed daily flows were updated every seven days with measured flows. The resulting forecast hydrograph had a R2= 0.90 and a difference in volume of 3.5 percent. The method developed needs to be refined and tested on additional years and basins, but the approach appears to be applicable to operational runoff forecasting using remote sensing data.
A TRADE‐OFF ANALYSIS OF ALTERNATIVE WATER USES1
Authors: Long Roger B.
Published: June 2007

ABSTRACT: In the western United States, hydropower and agriculture often cempete for surface waters. Since water markets are imperfect, allocations are often made through institutional arrangements and policy The purpose of this paper is to compare the gross water returns from agriculture with hydropower in terms of water use in Idaho. For the year 1986, returns from agriculture averaged $200 per acre‐foot, and returns from hydropower averaged $8.00 per acre‐foot.
VARIATION IN ADIRONDACK, NEW YORK, LAKEWATER CHEMISTRY AS FUNCTION OF SURFACE AREA1
Authors: Sullivan T J. , Kugler D. L. , Small M. J. , Johnson C. B. , Landers D. H. , Rosenbaum B. J. , Overton W.S. , Kretser W. A. , Gallagher J.
Published: June 2007

ABSTRACT: Data from a recent survey conducted by the Adirondack Lake Survey Corporation were used to evaluate the influence of lake surface area on the acid‐base status of lakes in Adirondack State Park, New York. Acid neutralizing capacity (ANC) in the small lakes (< 4 ha) occurred more frequently at extreme values (> 200, < 0 μeq L−1), whereas larger lakes tended to be intermediate in ANC. Consequently, acidic (ANC ≤ 0) and low‐pH lakes were typically small. The small lakes also exhibited lower Ca2+ concentration and higher dissolved organic carbon than did larger lakes. Lakes ≥ 4 ha were only half as likely to be acidic as were lakes ≥ 1 ha in area. These data illustrate the dependence of lake chemistry on lake surface area and the importance of the lower lake area limit for a statistical survey of lake water chemistry.
MANAGEMENT OF BASEFLOW AUGMENTATION: A REVIEW1
Authors: Ponce Victor M. , Lindquist Donna S.
Published: June 2007

ABSTRACT: Baseflow augmentation refers to the temporary storage of subsurface water in floodplains, streambanks, and/or stream bottoms during the wet season, either by natural or artificial means, for later release during the dry season to increase the magnitude and permanence of low flows. Management strategies for baseflow augmentation fall into the following categories: (1) range management, (2) upland vegetation management, (3) riparian vegetation management, (4) upland runoff detention and retention, and (5) the use of instream structures. The benefits of a management strategy focused on baseflow augmentation are many, including: (1) increased summer flows, (2) healthier riparian areas, (3) increased channel and bank stability, (4) decreased erosion and sediment transport, (5) improved water quality, (6) enhanced fish and wildlife habitat, (7) lower stream temperatures, and (8) improved stream aesthetics. This review has shown that baseflow augmentation has been successfully accomplished in a few documented cases. Given its clear impact on soil and water conservation, particularly in the semiarid western U.S., it appears that baseflow augmentation is a concept whose time has come. Research is needed on how to successfully integrate baseflow augmentation within comprehensive resource management strategies.
EFFECT OF SYSTEM LAYOUT ON SUBSURFACE DRAINAGE COST IN FLAT IRRIGATED LAND1
Authors: Gallichand J. , Prasher S. O. , Broughton R. S. , Metzger J. F. , Brichieri‐Colombi J. S. A.
Published: June 2007

ABSTRACT: The economic feasibility of large‐scale subsurface drainage projects in irrigated land is affected by construction costs. This study was conducted to evaluate the effect of two different types of subsurface drainage system layout on construction costs for a 1000 ha pilot area located in the Nile Delta of Egypt. The two types of layout studied were the conventional layout currently used in Egypt and the modified layout that was developed for reducing water losses from rice fields. When compared to the conventional layout, the modified layout resulted in a reduction of 6.74 percent in construction costs (714,464 US$ versus 766,142 US$). This cost reduction is explained by the need for lesser lengths of large diameter collector pipes with the modified layout, which results from the smaller drainage area of subsurface drainage systems (average 23.7 versus 30.8 ha). We have found that the cost of subsurface drainage can be minimized by reducing the area drained by each subsurface drainage system.
DECISION‐MAKING PROCESS ON THE DANUBE AND THE PLATTE1
Authors: Bleed A. , Nachtnebel H. P. , Bogardi I. , Supalla R. J.
Published: June 2007

ABSTRACT: Two case studies highlighting the institutional arrangements and decision‐making processes used to attempt to allocate water on large scale river systems in two countries are presented. In both cases the implementation of river plans has been blocked by conflicts between those who wish to use water for irrigation, hydropower, or municipal purposes and those who wish to maintain instream flows for fish and wildlife. To date conflict has blocked the implementation of a large hydropower scheme on the Danube River, downstream from Vienna, Austria, and the construction of municipal and agricultural projects, as well as the relicensing of an existing hydropower facility on the Platte River in Nebraska. Analysis of the decision‐making processes and institutional settings of both cases led to the identification of problem areas and development of recommendations that would support the achievement of compromise solutions for management.
LONGITUDINAL AND SEASONAL WATER CHEMISTRY VARIATIONS IN A NORTHERN APPALACHIAN STREAM1
Authors: Phillips Robert A. , Stewart Kenton M.
Published: June 2007

ABSTRACT: Quaker Run, a fourth order stream located in southwestern New York State, exhibits a highly unusual chemical gradient along its upper reaches. Weekly water samples showed an increase in the mean annual pH from 5.07 to 7.01 along a stretch of only 2.2 km. Mean alkalinity, calcium, magnesium, sodium, potassium, nitrate‐nitrite‐nitrogen, silica, and conductivity also increased appreciably over this distance. The study area receives some of the most highly acidic atmospheric deposition in the United States. Minimal buffering of these acidic inputs in the extreme upper watershed, and an abrupt downstream increase in buffering associated with changes in soil type, apparently produce the observed streamwater chemistry gradient. In contrast, a comparison between 11 midstream, downstream, and tributary sites showed relatively little variation in streamwater chemistry. In addition to the pronounced longitudinal chemistry changes along the upper portion of the stream, pronounced temporal chemistry variations were also observed at all sampling sites. High flow during snowmelt and heavy rains produced more dilute, acidic conditions, while streamwater pH and dissolved base cations were generally highest during low flow. Much of this temporal variation in streamwater chemistry is attributed to seasonal variation in residence times of soil water.
CLIMATE FACTOR FOR SMALL‐BASIN FLOOD FREQUENCY1
Authors: Lichty R.W. , Karlinger M.R.
Published: June 2007

ABSTRACT: A climate factor, CT, (T = 2–, 25‐, and 100‐year recurrence intervals) that delineates regional trends in small‐basin flood frequency was derived using data from 71 long‐term rainfall record sites. Values of CT at these sites were developed by a regression analysis that related rainfall‐runoff model estimates of T‐year floods to a sample set of 50 model calibrations. CT was regionalized via kriging to develop maps depicting its geographic variation for a large part of the United States east of the 105th meridian. Kriged estimates of CT and basin‐runoff characteristics were used to compute regionalized T‐year floods for 200 small drainage basins. Observed T‐year flood estimates also were developed for these sites. Regionalized floods are shown to account for a large percentage of the variability in observed flood estimates with coefficients of determination ranging from 0.89 for 2‐year floods to 0.82 for 100‐year floods. The relative importance of the factors comprising regionalized flood estimates is evaluated in terms of scale (size of drainage area), basin‐runoff characteristics (rainfall. runoff model parameters), and climate (CT).
A DISTRIBUTED DYNAMIC WATERSHED MODEL1
Authors: James Wesley P. , Kim Keu Whan
Published: June 2007

ABSTRACT:A distributed watershed model was developed to mathematically simulate overland and channel flow for a single‐event storm. The modeled watersheds in the study were subdivided into rectangular grid elements. All hydrologically significant parameters, such as land slope, rainfall and precipitation excess, were assumed to be uniform within each element. The Green‐Ampt method was adopted to generate precipitation excess for each element during the simulation period. A two‐dimensional diffusion wave model was used for overland flow routing and an iterative Alternative Direction Implicit scheme was used to solve the simultaneous overland flow equations. Once the overland flow became inflow to the channel, a one‐dimensional dynamic wave flood routing technique, based on a four‐point, implicit, non‐linear finite difference solution of the St. Venant equation of unsteady flow, was applied. A limited number of comparisons were made between simulated and observed hydrographs for areas of about one square mile. Given the appropriate parameters, the model was able to accurately simulate runoff for single‐event storms. This paper describes a distributed watershed model developed to simulate overland and channel flow. Comparisons were made between simulated and observed hydrographs for three watersheds. The model was able to accurately simulate the runoff for single‐event storms using 61‐m by 61‐m (200 ft by 200 ft) watershed grid elements.
DEVELOPMENT OF AN INTERDISCIPLINARY PLANNING MODEL FOR WATER AND FISHERY MANAGEMENT1
Authors: Cole Richard A. , Ward Frank A. , Ward Timothy J. , Wilson Robert M.
Published: June 2007

ABSTRACT: This paper describes the development of an interdisciplinary model that analyzes the effects of resource management decisions on New Mexico fishery production, yield, sportfishing effort, and economic benefit to anglers. The model recreates river flows and materials transported through reservoirs and their tailwaters from 1974 through 1987. Solar radiation, water temperature, phosphorus, nitrogen, suspended solids, and water exchange rates determine primary production. Organic loads from watershed sources, added to primary production, form a trophic base for sportfish forage. Fish production is partitioned into biomass and growth of each age class in sportfish and forage fish groups by differential responses to food type, light, water‐level fluctuation and predation. Fish biomass, with angler population distribution and site condition, contributes to determining angler effort and economic benefits. Model users can vary and analyze water level and quality, stocking, fishing regulations, site access, site facilities, and site entry fees. The model (on floppy disks with a user manual) is available for operation on MS DOS compatible computers with a hard disk. Contact R. M. Wilson, NMGF, State Capitol, Santa Fe, New Mexico, 87503.
A COMPARISON OF MODELS PREDICTING GROUND WATER LEVELS ON HILLSIDE SLOPES1
Authors: Reddi Lakshmi N. , Mo Lee In , Wu Tien H.
Published: June 2007

ABSTRACT: A comparative study of ground water level predictions on hillside slopes using two models is presented. The models are a simplified mass balance model that has components for evapotran‐spiration, recharge, and drainage; and a two‐dimensional finite difference model that employs kriging to estimate soil parameters and accounts for non‐uniform thickness of the soil layer. These models are representative of a wide range of modeling capabilities and are used to illustrate the sensitivity of ground water level predictions to the sophistication of the modeling techniques. The drainage and recharge components of the two models are evaluated and the importance of unsaturated flow in recharge computations is underscored. Piezometric observations in a small drainage depression on the slope of Kennel Creek Valley in Tongass National Forest, Alaska, were used to evaluate the two models. The results show that, although the predictions differ from the field observations, the simple physically‐based mass balance model predicts the ground water levels as well as the two‐dimensional model. It is suggested that caution should be exercised in using complex models to validate simpler models.
HYDROLOGIC RESPONSES OF AN AGRICULTURAL WATERSHED TO VARIOUS HYDROLOGIC AND MANAGEMENT CONDITIONS1
Authors: Razavian Daryoush
Published: June 2007

ABSTRACT: The hydrologic responses from an agricultural watershed in southeast Nebraska were investigated under an array of physiographic, hydrologic, meteorologic, and management conditions. For analytical purposes, the hydrologic responses were narrowed to include only runoff and sediment yield. The study was performed by utilizing the ANSWERS (Areal Nonpoint Source Watershed Environment Response Simulation) hydrologic‐simulation model. Results of this study indicate that, generally, nonstructural (agronomic) Best Management Practices (BMPs) have a more significant impact in controlling erosion and nonpoint‐source pollution than structurally oriented BMPs. The percentage of reduction in average soil loss as a result of changing tilage systems from conventional to chisel plow was in the mid‐40s. The corresponding percentages of reduction in sediment yield from the watershed under minimum tillage and no‐till systems were in the mid‐60s and mid‐80s, respectively. The impact of these management strategies on runoff varied considerably. That is primarily based on the watershed's antecedent soil moisture condition, land use, and the growth stage of crops. Generally, an intense, short, thunderstorm type of rainfall event had more relative impact on runoff, and therefore sediment yield than a long, gentle, and steady event.
WATER MANAGEMENT ISSUES FOR THE NINETIES1
Authors: Viessman Warren
Published: June 2007

ABSTRACT: This paper summarizes contemporary water management issues as recognized by 19 U.S. organizations. Only the issues are identified herein. Individual organization stands are not presented. Most suggestions for action are those of the author. Addresses of all organizations whose documents were reviewed are included in the Reference section so that those desiring to learn more about an organization's stand can readily make contact.
ITERATIVE EVALUATION OF A LAKE WATER QUALITY MANAGEMENT PROGRAM1
Authors: Herring John , Powell John
Published: June 2007

ABSTRACT: Local governments often face environmental problems that cross political boundaries. The onus for solution usually falls on the moat severely affected jurisdiction, others do nothing until impacted. Resolution of these problems requires cooperation across political boundaries which means that local governments must be persuaded first that there is a problem, and second that action is required to solve it. This paper presents a method to supply low cost, credible information that can be used to achieve consensus on problem solution. A case study of a lake water quality management problem is described. Formative evaluation techniques was adapted to provide a minimum of evidence which was then used to persuade less impacted local jurisdictions to cooperate in the problem solution.
HYDROLOGICAL ASPECTS OF THE 1988 DROUGHT IN ILLINOIS1
Authors: Wendland Wayne M.
Published: June 2007

ABSTRACT: Drought is evaluated in terms of the magnitude and duration of the 1988 spring and summer precipitation shortfall, and according to various components of the hydrologic budget, both surface and sub‐surface. The response time of some of these components is investigated, relative to the time of precipitation. Individual water users perceived a beginning and ending of the drought at different times relative to their activities. Some statistics better describe some components of a drought to some users, and better answer some questions, than do others.
PRIMARY PRODUCTIVITY AND PLANKTON COMMUNITIES IN A TWO‐RESERVOIR SERIES1
Authors: Melcher Jill , Sebetich Michael J.
Published: June 2007

ABSTRACT: It is suggested that new impoundments undergo an initial period of trophic upsurge lasting one to three years because of organic detritus and inorganic nutrients from the inundated basin. The new Monksville Reservoir in Passaic County, New Jersey, provided an opportunity to study the accelerated transformation of the Wanaque River into a 200‐ha lake and to compare productivity with the older Wanaque Reservoir located immediately downstream. A one‐year investigation of both reservoirs was conducted during 1988. The primary productivity (0.547 g C m−2 d−1) of the new Monksville Reservoir was not significantly different from that of the established Wanaque Reservoir (0.668 g C m−2 d−1). Mean surface chlorophyll a concentrations were similar (3.0–4.0 μg 1−1), although the Monksville Reservoir exhibited more pronounced chlorophyll peaks in spring and late autumn. Phytoplankton and zooplankton populations were consistently larger and fluctuated sharply in the Monksville Reservoir. Both reservoirs became thermally stratified, but only the Monksville Reservoir developed a metalimnetic dissolved oxygen minimum. The results demonstrated that the predicted trophic upsurge in the new reservoir did not occur in the first year therefore, the ecosystem dynamics did not fit the model for larger reservoirs.
BUFFER STRIPS TO PROTECT WATER SUPPLY RESERVOIRS: A MODEL AND RECOMMENDATIONS1
Authors: Nieswand George H. , Hordon Robert M. , Shelton Theodore B. , Chavooshian Budd B. , Blarr Steven
Published: June 2007

ABSTRACT: Buffer strips are undisturbed, naturally vegetated zones around water supply reservoirs and their tributaries that are a recognized and integral aspect of watershed management. These strips can be very effective in protecting the quality of public potable water supply reservoirs by removing sediment and associated pollutants, reducing bank erosion, and displacing activities from the water's edge that represent potential sources of nonpoint source pollutant generation. As part of a comprehensive watershed management protect for the State of New Jersey, a parameter‐based buffer strip model was developed for application to all watersheds above water supply intakes or reservoirs. Input requirements for the model include a combination of slope, width, and time of travel. The application of the model to a watershed in New Jersey with a recommended buffer strip width that ranges from 50 to 300 feet, depending upon a number of assumptions, results in from 6 to 13 percent of the watershed above the reservoir being occupied by the buffer.
THE OPTIMALITY OF CAPACITY SHARING IN STOCHASTIC DYNAMIC PROGRAMMING PROBLEMS OF SHARED RESERVOIR OPERATION1
Authors: Alaouze Chris M.
Published: June 2007

ABSTRACT: This paper is concerned with finding an optimal allocation of water entitlements for each of two users of water who share a reservoir. Two instruments of allocation are considered. The first, release sharing, involves sharing the releases from the reservoir; the second, capacity sharing, is concerned with allocating to each user of water a share of inflows, reservoir capacity and leakage and evaporation losses. Stochastic dynamic programming problems of reservoir operation under each type of sharing arrangement are formulated. It is shown that the maximum discounted expected profit from reservoir operation over the life of the storage using capacity sharing is at least as large as that obtained using release sharing and that release sharing is not Pareto efficient.
RUNOFF AND SEDIMENT PRODUCTION FROM BURNED FOREST SITES IN THE GEORGIA PIEDMONT1
Authors: Shahlaee A. K. , Nutter W. L. , Burroughs E. R. , Morris L. A.
Published: June 2007

ABSTRACT: Runoff and sediment production was measured under simulated and natural rain from 1×5 m plots established on a cutover and burned mixed pine‐hardwood site in the Georgia Piedmont. Trees on the study site were cut and removed without mechanical disturbance. Slash was removed, kiln dried and replaced on the slope, and burned prior to plot installation. Three slopes, two rainfall intensities, three rainfall simulations representing three soil moisture conditions, and two replicate plots were used. The experiment was repeated four times during the period July 1989‐July 1990 to investigate the effects of temporal changes in surface conditions and particularly root mat and residual forest floor decemposition. Runoff and sediment production from natural rainfall events was also measured from these plots during the period February‐October 1990. Results of all measurements indicate that runoff and sediment production were generally low because of the protection afforded by the residual forest floor following burning. However, temporary hydrophobic conditions caused by a dry organic layer produced relatively high runoff rates and high sediment for the first few minutes of runoff for some of the simulated rainfall applications.
ANTIDEGRADATION WATER QUALITY CRITERIA FOR THE DELAWARE RIVER: A DISTRIBUTION‐FREE STATISTICAL APPROACH1
Authors: Jay Breidt F , Roes Duane C. , Wagner Joel I. , Flora Mark D.
Published: June 2007

ABSTRACT: Existing water quality for the Middle Delaware Scenic and Recreational River is significantly better than is required by current standards, leaving a potential for degradation. A method is presented for deriving candidate antidegradation water quality criteria for this segment of the Delaware River using statistical analysis of historic (ambient) water quality data. Data for 34 water quality parameters are first evaluated for data density, serial correlation, trend, seasonality, and other factors. These preliminary analyses are based on observation of data plots and application of distribution‐free statistical techniques that are insensitive to outliers and are robust to relatively mild violations of basic assumptions. Data for 12 of the parameters have sufficient density for further analysis and can reasonably be modeled as independent and identically distributed over time (either seasonally or for the entire data sets). For these 12 parameters, distribution‐free statistical methods are developed and used to derive intervals within which there is high confidence (usually greater than 95 percent) that the quantiles with potential use as anti‐degradation criteria (the 0.85th, 0.90th, and 0.95th quantiles in this study) for a particular parameter lie.
INORGANIC CONTAMINANTS IN DRINKING WATER CORRELATED WITH DISEASE OCCURRENCE IN NEBRASKA1
Authors: Bednar C. M. , Kies C.
Published: June 2007

ABSTRACT: Levels of nitrate and other inorganic contaminants in the drinking water of 453 Nebraska communities in 1986 were compared with health data for counties in which these communities were located. Data used included death rates per 100,000 population from heart disease, cancer, cerebrovascular disease, pneumonia and chronic lung disease, plus the rate of birth defects. Water samples from 42 communities exceeded the 0.01 mg/liter state and federal standards for selenium while 19 exceeded the 10 mg/liter NO3‐N standard. Statistical analysis using Pearson's correlation coefficient method showed no significant relationship between nitrate or selenium and any of the health effects studied. Only barium, fluoride, and chromium were weakly but significantly (P<0.05) correlated to one or more of the health effects. Approximately one‐third of the water samples high in NO3‐N also had high levels of selenium. In some communities, the presence of nitrate also signaled the presence of barium, chromium, or arsenic. Results appear to indicate no immediate health risks related to levels of nitrate, selenium, or other inorganic contaminants in Nebraska drinking water. However, this type of statistical analysis cannot be interpreted as proving or disproving a cause and effect relationship.
ANALYSIS AND MODELING OF LONG‐TERM STREAM TEMPERATURES ON THE STEAMBOAT CREEK BASIN, OREGON: IMPLICATIONS FOR LAND USE AND FISH HABITAT1
Authors: Hostetler S. W.
Published: June 2007

ABSTRACT: Steamboat Creek basin is an important source of timber and provides crucial spawning and rearing habitat for anadromous steelhead trout (Oncorhynchus mykiss). Because stream temperatures are near the upper limit of tolerance for the survival of juvenile steelhead, the possible long‐term effect of clear‐cut logging on stream temperatures was assessed. Twenty‐year (1969–1989) records of summer stream temperature and flow from four tributaries and two reaches of Steamboat Creek and Boulder Creek (a nearby unlogged watershed) were analyzed. Logging records for the Steamboat Creek basin and air temperature records also were used in the analysis. A time‐series model of the components of stream temperature (seasonal cycle of solar radiation, air temperature, streamflow, an autoregressive term of order 1, and a linear trend variable) was fitted to the water‐temperature data. The linear trend variable was significant in all the fitted models except Bend Creek (a tributary fed by cool ground‐water discharge) and Boulder Creek. Because no trends in either climate (i.e., air temperature) or streamflow were found in the data, the trend variable was associated with the pre‐1969 loss and subsequent regrowth of riparian vegetation and shading canopies.
SPACE‐TIME TRADEOFFS ACROSS THE HYDROLOGIC DATA SETS OF COMPETING RAINFALL‐RUNOFF MODELS: A PRELIMINARY ANALYSIS1
Authors: Loague Keith
Published: June 2007

ABSTRACT: The concept of a space‐time tradeoff is extended to the hydrologic data sets of competing rainfall‐runoff modeling techniques. Examples are given by comparing the performance of a regression model and a quasi‐physically based model using data from an experimental catchment and data synthetically generated. Space‐time tradeoffs are demonstrated within the data sets of the two modeling techniques, but not across the competing hydrologic data sets.
GROUND WATER HYDRAULICS CONSIDERATIONS REGARDING LANDFILLS1
Authors: Haitjema Henk M.
Published: June 2007

ABSTRACT: Landfill siting and design guidelines or regulations differ from state to state. Most include hydrogeological criteria, referring to hydraulic conductivities, aquifers, ground water flow patterns, contaminant travel times, and distance between landfill and sensitive targets for contaminants, etc. However, almost all of the existing hydrogeological guidelines are incomplete, inconsistent, or both. The aquitard between landfill and regional aquifer frequently offers less resistance to leachate migration than compliance with regulations may suggest. Residence times of leachate, that makes it through the landfill liner, is often overestimated. Monitoring wells in the regional aquifer are unreliable detectors of local leaks in a landfill. If a landfill does leak, costly aquifer restoration is called for. For traditional landfill designs, ground water monitoring considerations suggest the siting over homogeneous sand and gravel aquifers, rather than over complex till environments. An alternative landfill design criterion is suggested, which is based on a negative hydraulic gradient underneath the landfill. This design guarantees ground water protection, simplifies landfill monitoring, and generally enhances the landfill economy.
ANNUAL EVAPOTRANSPIRATION OF NATWE VEGETATION IN A MEDITERRANEAN‐TYPE CLIMATE1
Authors: Turner Kenneth M.
Published: June 2007

ABSTRACT: Annual evapotranspiration from a watershed (ETws) is a function of annual precipitation (P) and fraction of the watershed covered by shrubs and trees (C). Other characteristics are not significant in explaining variance of ETws. A rational equation, ETws = (1‐C) ETg + CETst, wherein ETg is the ET of herbaceous cover and ETst is the ET of shrubs and trees, is proposed. The equation has been calibrated for ET and P in inches for the watershed of Lake Cachuma on the Santa Ynez River. This equation, ETmax = 2.14(1‐C)P0.647+ 4.53 C1.76 P0.68, is recommended for estimating maximum annual ET demand for conceptual models. Where C is not known, the upper limit of ET = f (P) may be approximated by use of 0.65 for C. The equation has been derived for large unmanaged watersheds. Applicability for evaluation of contemporary multiple purpose vegetation management should be determined by studies of the hydrology of small openings in shrub and tree cover.
WATERSHED CONFIGURATION AND GEOGRAPHIC INFORMATION SYSTEM PARAMETERIZATION FOR SPUR MODEL HYDROLOGIC SIMULATIONS1
Authors: Sasowsky Kathryn Connors , Gardner Thomas W.
Published: June 2007

ABSTRACT: A grid cell geographic information system (GIS) is used to parameterize SPUR, a quasi‐physically based surface runoff model in which a watershed is configured as a set of stream segments and contributing areas. GIS analysis techniques produce various watershed configurations by progressive simplification of a stream network delineated from digital elevation models (DEM). We used three watershed configurations: ≥ 2nd, ≥ 4th, and ≥ 13th Shreve order networks, where the watershed contains 28, 15, and 1 channel segments with 66, 37, and 3 contributing areas, respectively.

Watershed configuration controls simulated daily and monthly sums of runoff volumes. For the climatic and topographic setting in southeastern Arizona the ≥ 4th order configuration of the stream network and contributing areas produces results that are typically as good as the ≥ 2nd order network. However both are consistently better than the ≥ 13th order configuration. Due to the degree of parameterization in SPUR, model simulations cannot be significantly improved by increasing watershed configuration beyond the ≥ 4th order network. However, a range of Soil Conservation Service curve numbers derived from rainfall/runoff data can affect model simulations. Higher curve numbers yield better results for the ≥ 2nd order network while lower curve numbers yield better results for the ≥ 4th order network.
LONG‐RANGE STREAMFLOW FORCASTING USING NONPARAMETRIC REGRESSION1
Authors: Smith James A.
Published: June 2007

ABSTRACT: A class of nonparametric procedures is developed for producing long‐range streamflow forecasts. The forecasting procedures, which are based solely on daily streamflow data, utilize nonparametric regression to relate a forecast variable to a covariate variable. The forecast variable is a function of future streamflow and can take a wide variety of forms. The covariate variable is a function of antecedent streamflow. The forecasting procedures are quite flexible, both in terms of the duration of the forecast period and the types of forecast variables that can be considered. The procedures are used to develop long‐term (1–4 months) forecasts of minimum daily flow of the Potomac River at Washington, D.C. This forecast information is an integral component of water management activities for the Washington, D.C. metropolitan area.
ESTIMATING TRANSMISSIVITY AND HYDRAULIC CONDUCTIVITY OF CHICOT AQUIFER FROM SPECIFIC CAPACITY DATA1
Authors: Rao G. N. , Beck J. N. , Murray H. E. , Nyman D. J.
Published: June 2007

ABSTRACT: Specific capacity data obtained from Well Construction reports which are available from USGS offices, can provide useful estimates of tranamissivity (T), and hydraulic conductivity (K), of an aquifer. The Chicot Aquifer in Louisiana is one of the largest sources of fresh ground water in North America. Hydrologic data collected for the Chicot Aquifer indicate that specific capacity tests can be used in estimating local and regional values for T and K, if the Cooper‐Jacob equation for transient flow is used with proper corrections for well loss and partial penetration. Where full scale pumping test data are scarce, specific capacity test data that are adequately distributed spatially can be used to map changes in T and K values and can be summarized statistically to indicate applicable regional values. A computer program called “TGUESS” which is available from International Ground Water Modeling Center, Holcomb Research Institute, was used in this study. The contour maps for T and K values are prepared for different well depth intervals to avoid wide variation of values.
IDENTIFICATION OF DISSOLVED‐CONSTITUENT SOURCES IN MINE‐SITE GROUND WATER USING BATCH MIXING1
Authors: Clark Gregory M. , Williams Robert S.
Published: June 2007

ABSTRACT: Batch‐mixing experiments were used to help identify lithologic and mineralogic sources of increased concentrations of dissolved solids in water affected by surface coal mining in northwestern Colorado. Ten overburden core samples were analyzed for mineral composition and mixed with distilled water for 90 days until mineral‐water equilibrium was reached. Between one day and 90 days after initial contact, specific conductance in the sample mixtures had a median increase of 306 percent. Dissolved‐solids concentrations ranged from 200 to 8,700 mg/L in water samples extracted from the mixtures after 90 days.

Mass. balance simulations were conducted using the geochemical models BALANCE and WATEQF to quantify mineral‐water interactions occurring in five selected sample mixtures and in water collected from a spring at a reclaimed mine site. The spring water is affected by mineral‐water interactions occurring in all of the lithologic units comprising the overburden. Results of the simulations indicate that oxidation of pyrite, dissolution of dolomite, gypsum, and epsomite, and cation‐exchange reactions are the primary mineral‐water interactions occurring in the overburden.

Three lithologic units in the overburden (a coal, a sandstone, and a shale) probably contribute most of the dissolved solids to the spring water. Water sample extracts from mixtures using core from these three units accounted for 85 percent of the total dissolved solids in the 10 sample extracts. Other lithologic units in the overburden probably contribute smaller quantities of dissolved solids to the spring water.
REMOVAL OF FLOODWATER SEDIMENTS BY A CLEARCUT TUPELO‐CYPRESS WETLAND1
Authors: Aust W. Michael. , Lea Russ , Gregory James D.
Published: June 2007

ABSTRACT: A palustrine water tupelo (Nyssa aquatica L.)‐baldcy‐press (Taxodium distichum (L.) Rich.) swamp in southwestern Alabama was subjected to three types of disturbance, including helicopter logging, rubber‐tired skidder logging simulation, and helicopter logging followed by an herbicide application. An adjacent undisturbed stand served as a control area. Post‐harvest collection of sedimentation data revealed that the herbaceous and woody vegetation regrowth within the helicopter and skidded clearcut areas trapped more sediments than did the control or herbicide treatment areas. Clearcutting, followed by plant regrowth, improved the wet‐land's capacity to remove sediments from overbank flow flood waters.
GENERALIZED SKEW COEFFICIENTS OF ANNUAL FLOODS FOR LOUISIANA STREAMS1
Authors: Naghavi Babak , Yu Fang Xin
Published: June 2007

ABSTRACT: A generalized skew map for Louisiana streams was developed using data from Louisiana, Mississippi, Arkansas, and Texas with 20 or more years of annual flood records. A comparison between the newly developed Louisiana Generalized Skew Map (LGSM) and the generalized skew map recommended by the U.S. Water Resources Council (WRCGSM) was performed. The mean square error for the LGSM was 16 percent less than that of WRCGSM in direct application of the two maps. Performance of the new map was compared with the WRCGSM and with a regional analysis procedure through its application to the Log Pearson Type 3 (LP3) distribution. Two‐thirds of the stations tested had lower standardized root mean square deviations (SRMSD) by a narrow margin using the skew coefficients obtained from LGSM instead of WRCGSM. The regional analysis also performed as well as the LGSM in terms of SRMSD. Thus, it was concluded that both LGSM and the regional analysis provide a more reliable tool for flood frequency analysis for Louisiana streams with short annual flood records.
POLLUTANT LOADS IN URBAN STORMWATER: REVIEW OF METHODS FOR PLANNING‐LEVEL ESTIMATES1
Authors: Marsalek Jiri
Published: June 2007

ABSTRACT: A review of methods for planning‐level estimates of pollutant loads in urban stormwater focuses on transfer of charac. teristic runoff quality data to unmonitored sites, runoff monitoring, and simulation models. Load estimation by transfer of runoff quality data is the least expensive, but the accuracy of estimates is unknown. Runoff monitoring methods provide best estimates of existing loads, but cannot be used to predict load changes resulting from runoff controls, or other changes of the urban system. Simulation models require extensive calibration for reliable application. Models with optional formulations of pollutant build up, washoff, and transport can be better calibrated and the selection of options should be based on a statistical analysis of calibration data. Calibrated simulation models can be used for evaluation of control alternatives.
IMPLICATIONS OF A DRAWDOWN OF THE SNAKE‐COLUMBIA RWER ON BARGE TRANSPORTATION1
Authors: Martin Michael , Hamilton Joel R. , Casauant Ken
Published: June 2007

ABSTRACT: The listing of the Snake‐Columbia River salmon under the Endangered species Cut will lead to a set of river management changes aimed at species recovery. One measure almost certain to be implemented is a periodic river drawdown. A drawdown will speed fish migration downriver but will also temporarily close the river to barge transportation. Grain shippers in the region rely on the barge carriage to move a significant share of annual production to export elevators on the Lower Columbia. A number of other bulk commodities utilize barges as well. This study outlines the aggregate and distributional economic implications of a suspension of barge transportation resulting from a river drawdown.
SELECTING A MULTICRITERION DECISION MAKING TECHNIQUE FOR WATERSHED RESOURCES MANAGEMENT1
Authors: Tecle Aregai
Published: June 2007

ABSTRACT: A method for selecting a most appropriate multicritenon decision making (MCDM) technique for watershed resources management is modeled as a multicriterion problem. The procedure consists of identifying a set of feasible MCDM techniques, and evaluating them with respect to four sets of choice criteria, namely (1) problem related, (2) decision‐maker (DM)/analyst related, (3) technique‐related, and (4) solution‐related criteria. Altogether 15 techniques are evaluated in terms of 24 criteria, forming an evaluation matrix of criteria versus alternative MCDM techniques. The evaluation matrix is then analyzed by means by a composite programming algorithm resulting in a preference ranking of the alternatives. Application of the techniques to a watershed resources management problem illustrates the method throughout the paper. (KEY TERMS: alternative selection; watershed resources management; multicriterion decision making; composite programming.)
A GAME‐THEORETIC APPROACH TO ACID RAIN ABATEMENT: CONFLICT ANALYSIS OF ENVIRONMENTAL LOAD ALLOCATION1
Authors: Okada Norio , Mikami Yoshiko
Published: June 2007

ABSTRACT: The detrimental impacts of acid rain have become widely publicized, but effective and equitable methods to mitigate the acid rain problem remain to be found. This paper focuses on conflicts involved in allocation of the total emission loads to be reduced to respective pollution sources of acid rain, and proposes a game‐theory approach to the resolution of the conflict. With an example abstracted from a hypothetical case study in the United States of America and Canada, a systematic analysis is performed and policy implications of the results examined to assess the applicability of the proposed model.
DETERMINATION OF BEST TIMING FOR POULTRY WASTE DISPOSAL: A MODELING APPROACH1
Authors: Edwards D. R. , Daniel T C. , Marbun O.
Published: June 2007

ABSTRACT: Confined production of poultry results in significant volumes of waste material which are typically disposed of by land application. Concerns over the potential environmental impacts of poultry waste disposal have resulted in ongoing efforts to develop management practices which maintain high quality of water downstream of disposal areas. The timing of application to minimize waste constituent losses is a management practice with the potential to ensure high quality of streams, rivers, and lakes downstream of receiving areas. This paper describes the development and application of a method to identify which time of year is best, from the standpoint of surface water quality, for land application of poultry waste. The procedure consists of using a mathematical simulation model to estimate average nitrogen and phosphorus losses resulting from different application timings, and then identifying the timings which minimize losses of these nutrients. The procedure was applied to three locations in Arkansas, and three different criteria for optimality of application timing were investigated. One criterion was oriented strictly to water quality, one was oriented only to crop production, and the last was a combination. The criteria resulted in different windows of time being identified as optimal. Optimal windows also varied with location of the receiving area. The results indicate that it is possible to land‐apply poultry waste at times which both minimize nutrient losses and maximize crop yield.
EFFECTS OF WOODY VEGETATION ON SANDY LEVEE INTEGRITY1
Authors: Shields F Douglas , Gray Donald H.
Published: June 2007

he influence of woody vegetation on the reliability of a sandy levee was investigated using field data in seepage and slope stability analyses. Field data were collected from selected sites within a 10‐km segment of a channel levee on the Sacramento River near Elkhorn, California. Root architecture and distribution were determined using the profile‐wall method in which root cross sections were exposed in the vertical wall of an excavated trench. Transects running both parallel and perpendicular to the crest of the levee were excavated at six sites. Each site was dominated by different plant species: five sites were adjacent to trees or woody shrubs, while one supported only herbaceous growth. Lateral plant roots were primarily restricted to, and modified, the near‐surface soil horizons to a depth of approximately 1 meter. Root area ratios (RARs) did not exceed 2.02 percent and generally decreased exponentially with depth. At depths greater than 20 cm, mean RARs for sites dominated by wood species were not significantly different from the mean RAB for the herbaceous site. No open voids clearly attributable to plant roots were observed. Roots reinforced the levee soil and increased shear resistance in a measurable manner. Infinite slope and circular arc stability analyses were performed on the landward and riverward slopes under different hydraulic loading conditions. Infinite slope analyses indicated increasing root area ratio from 0.01 percent to 1 percent increased the factor of safety from less than one to more than seven. Circular arc analyses indicated that even the lower measured root concentrations sufficed to increase safety factors for arcs with maximum depths of about 1 m from less than one to about 1.2. Our findings suggest that allowing woody shrubs and small trees on levees would provide environmental benefits and would enhance structural integrity without the hazards associated with large trees such as wind‐throwing.
OFFSITE MEASUREMENT OF THE VISUAL CLARITY OF WATERS1
Authors: Davies‐Colley Robert J. , Smith David G.
Published: June 2007

ABSTRACT: The black disk method for measuring visual water clarity in situ is becoming established as a simple but robust method for optically characterizing natural waters. However, in spite of its virtues, the method is limited by a practical visibility minimum of around 0.1 m and the requirement for direct access to the water body at a point where there is adequate lighting for the visual observations. A method has been devised for measuring black disk clarity off‐site on samples of waters, diluted if necessary, and contained in a trough constructed of galvanized steel. In 23 streams, rivers, and lakes of diverse optical and physical character, measurements of visual clarity of water samples contained in troughs agreed closely with in situ measurements and correlated well (inversely) with the beam attenuation coefficient measured by transmissometer. Therefore, at sites where in situ measurement is difficult, visual clarity of waters can be measured offsite on a water sample. Furthermore, the visibility of samples diluted with tap water of known clarity was predictable from a simple balance on light attenuation. This means that useful visual clarity measurements on very turbid waters and effluents can be made in a trough containing volumetrically diluted samples, so extending application of the black disk method to very low visual ranges.
GROUND‐WATER RECHARGE THROUGH ACTWE SAND DUNES IN NORTHWESTERN NEVADA1
Authors: Berger David L.
Published: June 2007

ABSTRACT: Most water‐resouree investigations in semiarid basins of the Great Basin in western North America conclude that ground‐water recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground‐water recharge. The potential for this previously undocumented recharge was investigated in an area covered by sand dunes in Desert Valley, northwestern Nevada, using a deep percolation model. The model uses daily measurements of precipitation and temperature th determine energy and moisture balances, from which estimates of long‐term mean annual recharge are made. For the study area, the model calculated a mean annual recharge rate of as much as 1.3 inches per year, or 17 percent of the long‐term mean precipitation. Model simulations also indicate that recharge would be virtually zero if the study area were covered by vegetation rather than dunes.