bluuebunny/crossref_metadata_2025 huggingface dataset:
SPATIAL VARIABILITY IN SELECTED PHYSICAL CHARACTERISTICS AND PROCESSES IN CROSS LAKE, NEW YORK1
Authors: Effler Steven W. , Carter Charles F.
Published: June 2007

ABSTRACT: Short‐circuiting of the inflow occurs from the Seneca River across the southern portion of Cross Lake, New York. Spatial differences in thermal stratification, transparency and light attenuation, and net sedimentation are documented for the lake. The depth of the epilimnion was generally deeper, and the temperature gradient in the metalimnion was at times lower, at a deep‐water location proximate to the short‐circuiting zone, than at a position more remote from the inflow. Transparency was generally lower, and light attenuation greater, proximate to the short‐circuiting zone, indicating the contribution of attenuating components from the river. The net sedimentation rate in the short‐circuiting zone was greater and temporally more irregular than for a deep‐water position remote from the river inflow. The spatial differences in the physical characteristics and processes in Cross Lake are attributable to the magnitude and position of the inflow from the Seneca River.
A GEOGRAPHIC INFORMATION SYSTEM TO PREDICT NON‐POINT SOURCE POLLUTION POTENTIAL1
Authors: Gilliland Martha W. , Baxter‐Potter Wanada
Published: June 2007

ABSTRACT: Bacterial densities (total coliform, fecal coliform, and fecal streptococci) and suspended solids in runoff from a feedlot, pasture, and corn field were measured. Densities of fecal coliform were highest from the feedlot but were 1000 to 10,000 times greater than the water quality standard for swimmable waters from all three land uses. Densities of fecal streptococci were highest from the corn field, which suggests that wildlife are the source of bacteria. Fecal coliform/fecal streptococci ratios distinguished cattle from wildlife as the source of bacterial pollution both among land uses and among seasons of the year. Suspended solids concentrations in runoff ranged from 423 to 925 mg/l and were highest from the corn field.

A Geographic Information System (GIS), which utilizes a raster or grid‐cell format, was developed to include algorithms associated with non‐point source pollution. The system accepts digitally mapped information on soil type, topography, and land use. It calculates characteristics such as slope and slope length, and relates these characteristics to soils and land use parameters in order to produce three dimensional maps of runoff potential, sediment pollution potential, and bacterial pollution potential. It offers the advantages of retaining the geographic character of pollution potential information and of conveying in three‐dimensional graphical terms the effects of topography, soil type, land use, and land management practices.
INSTITUTIONAL ANALYSIS IN COMMUNITY DECISION‐MAKING: A CASE EXAMPLE FROM SOUTHERN ARIZONA1
Authors: Cortner Hanna J. , Marsh Floyd L.
Published: June 2007

ABSTRACT: While there is increasing recognition of the need to consider institutional factors in water resources decision‐making, there are few specific methods available to use in actually conducting an institutional analysis. The lack of such methods has spurred interest in going beyond begging water resource agencies to conduct institutional analyses to developing more refined tools to use in the analysis process. However, as more complex systems of analysis are developed, it is important not to lose sight of the value that less objective and participatory approaches to institutional analysis may have in solving institutional problems. Improving the techniques and tools of institutional analysis should not mean developing complex methods or models that can only be manipulated and understood by the trained analyst. The advantages and disadvantages of full participation by stakeholders in the institutional analysis process are discussed by describing the efforts of a local community organization in Tucson, Arizona, to study the need for a basinwide management entity.
A DIGITAL CONTROLLER FOR DISCRETE STAGE ACTIVATION OF AUTOMATIC PUMPING SAMPLERS1
Authors: Vowell Jeffery L. , Hutchens Chriswell G.
Published: June 2007

ABSTRACT: An electronic controller was developed to facilitate water sampling at discrete stage heights in perennial mountain streams of southeast Oklahoma. The controller operates in conjunction with an automatic pumping sampler and a magnetic, relay transducer. In response to changes in stage, the transducer generates an electrical pulse when relays are closed by a magnetic float. The controller monitors these relay closures and signals the sampler to pump a single sample at each desired water level during both rising and falling stages. After a sample is taken, additional switch closures at that stage axe ignored until the relay immediately above or below is closed. Inadvertent switch closures caused by turbulent stage fluctuations are not translated to the sampler thus eliminating duplicate or multiple samples at a given stage. Field testing has proven this device to be a reliable component with a range of applications for improving water quality sampling systems. The controller features battery operation, low power consumption, circuit simplicity and can be easily constructed for less than $100, including parts and labor.
ALTERNATIVE DEMAND MODEL ESTIMATORS FOR BLOCK RATE PRICING1
Authors: Billings R. Bruce
Published: June 2007

ABSTRACT: Three alternative demand model estimators for water sold under block rate tariffs are examined. The models are conceptually discussed and empirically estimated using cross‐section and time‐series data from Tucson, Arizona. While all three techniques produce plausible elasticity estimates, the ordinary least squares and censored sample techniques are shown to produce statistically biased results.
A STOCHASTIC DYNAMIC PROGRAMMING BASED APPROACH TO THE OPERATION OF A MULTI‐RESERVOIR SYSTEM1
Authors: Tai F.‐K. , Goulter I. C.
Published: June 2007

ABSTRACT: An heuristic iterative technique based upon stochastic dynamic programming is presented for the analysis of the operation of a three reservoir ‘Y’ shaped hydroelectric system. The technique is initiated using historical inflow data for the downstream reservoir. At each iteration the optimal policies for the downstream hydroelectric generating unit are used to provide relative weightings or targets for operation of upstream reservoirs. New input inflows to the downstream reservoir are then obtained by running the historical streamflow record through the optimal policies for the upstream reservoirs. These flows are then used to develop a new operating policy for the downstream reservoir and hence new targets for the upstream reservoirs. The process is continued until the operating policies for each reservoir provide the same overall system benefit for two successive iterations. Results obtained from the procedure are compared to the results obtained by historical operation of the system. The procedure is shown to develop operating policies which give benefits which are as close to the historical benefits as can be expected given the choice of the number of storage state variables.
PREDICTING THE SUMMER PEAK BIOMASS OF FOUR SPECIES OF BLUE‐GREEN ALGAE (CYANOPHYTA/CYANOBACTERIA) IN SWEDISH LAKES1
Authors: Smith V. H. , Willén E. , Karlsson B.
Published: June 2007

ABSTRACT: Stepwise multiple regression analysis was used to develop models predicting the summer peak biomass of Aphanizomenon flos‐aquae, Anabaena flos‐aquae, Oscillatoria agardhii, and Microcystis aeruginosa in four Swedish lakes. These analyses suggest that while epilimnetic total phosphorus concentration is the principal predictor of their peak biomass, other factors such as station mean depth, water temperature, total nitrogen, and total CO2 concentration are also important.
ENHANCEMENT OF RIPARIAN ECOSYSTEMS WITH CHANNEL STRUCTURES1
Authors: DeBano Leonard F. , Heede Burchard H.
Published: June 2007

ABSTRACT: Naturally occurring and man‐made structures can be used for enhancing the development of riparian zones. Naturally occurring structures are cienagas, beaver dams, and log steps. Man‐made structures include large and small channel structures and bank protection devices. All these structures affect streamflow hydraulics and sedimentation and can create a more favorable environment for riparian zone establishment. However, when they are used improperly, they can be destructive to existing riparian zones. Since stream processes are generally slow, long‐time spans may pass before the effects of management action, good or bad, become visible. Also, the effects of large dam installations may appear a long distance downstream from the dam. Therefore, investigations must be of a wide scope. Interactions between riparian site, channel, and streamflow may be so complex that an interdisciplinary approach is required.
CHEMICAL REACTIONS SIMULATED BY GROUND‐WATER‐QUALITY MODELS1
Authors: Grove David B. , Stollenwerk Kenneth G.
Published: June 2007

ABSTRACT: Recent literature concerning the modeling of chemical reactions during transport in ground water is examined with emphasis on sorption reactions. The theory of transport and reactions in porous media has been well documented. Numerous equations have been developed from this theory, to provide both continuous and sequential or multistep models, with the water phase considered for both mobile and immobile phases. Chemical reactions can be either equilibrium or non‐equilibrium, and can be quantified in linear or non‐linear mathematical forms. Non‐equilibrium reactions can be separated into kinetic and diffusional rate‐limiting mechanisms. Solutions to the equations are available by either analytical expressions or numerical techniques. Saturated and unsaturated batch, column, and field studies are discussed with one‐dimensional, laboratory‐column experiments predominating. A summary t able is presented that references the various kinds of models studied and their applications in predicting chemical concentrations in ground waters.
THE IMPACTS OF WATERWAY USER FEES ON GRAIN TRANSPORTATION ON THE SNAKE‐COLUMBIA RIVER1
Authors: Lubis Rusidan , Martin Michael V. , McMullen B. Starr
Published: June 2007

ABSTRACT: Grain transportation is a major economic activity on the multiple use Snake‐Columbia River System. Congress is currently considering increased transportation user fees aimed at recapturing federal expenditures for waterway operations and maintenance. Three types of fee structure and four levels of cost recovery are evaluated using a network program model. In each case traffic is diverted away from the river to other Puget Sound ports via truck and rail transport modes. Grain shippers in the region will be adversely affected by a higher transport bill. The Lower Columbia River port economic activities will be negatively affected; however, competitive uses of the river, recreation, and hydroelectric generation will likely benefit modestly.
RUNOFF IMPOUNDMENT FOR SUPPLEMENTAL IRRIGATION IN TEXAS1
Authors: Krishna J. H. , Arkin G. F. , Martin J. R.
Published: June 2007

ABSTRACT: The current increase in the demand for water by municipal, industrial, and other users is likely to result in approximately one‐third less water being available for agricultural use in Texas by the year 2000. As water supplies diminish, the rainfall excess needs to be used more efficiently. Large amounts of runoff occur in the eastern part of Texas that could be collected in small impoundments and utilized for crop production. Farmers in water‐surplus basins or subbasins can apply for a permit to divert surface water into small on‐farm impoundments to be used for supplemental irrigation. The costs for runoff collection and two supplemental irrigations, which amount to a total of 4 in./yr., are estimated to be approximately $60/acre/year. Depending upon the crop produced, the estimated increase in gross income from supplemental irrigation ranges from about $80 to more than $100 per acre annually.
NONLINEAR SOLUTIONS OF THE BQUSSINESQ EQUATION AND COMPARISONS WITH FIELD OBSERVATIONS1
Authors: Leznicki Jacek K. , Korfiatis George P.
Published: June 2007

ABSTRACT: Two models based on variations of the one dimensional Boussinesq equation are presented. The models are formulated by treating each of the two nonlinearities appearing in the equation separately, and the resulting equations are solved by implicit finite difference techniques. The models have been used to predict drawdowns created from large scale pumping at an open coal mine pit dewatering project in Poland. The predictions were found to be in good agreement with data collected over a period of seven years.
PATTERNS OF WATERSHED MONTHLY RUNOFF1
Authors: Snyder W. M. , Thomas A. W.
Published: June 2007

ABSTRACT: Two dimensional sliding polynomials were adapted to pattern analysis of watershed monthly rainfall and runoff. Contours of runoff in the two‐dimensional space of time and rainfall are constructed on a grid of 16 nodes whose values are determined by least squares. This method is form free, hence derived patterns are not biased to selected functional forms, but can directly represent the smoothed data. Values of the nodes are localized averages of the data constrained by required mathematical continuity across the grid of values. An advantage of the method is that the standard deviation can be calculated for each node, thus producing patterns of uncertainty of the deterministic component revealed by the data.
REAL‐TIME SNOW SIMULATION MODEL FOR THE MONONGAHELA RIVER BASIN1
Authors: Hoggan Daniel H. , Peters John C. , Loehlein Werner
Published: June 2007

ABSTRACT: The Pittsburgh District, U.S. Army Corps of Engineers, is responsible for operating two multipurpose reservoirs in the 7384 square mile (19198 square kilometer) Monongahela Basin. A third reservoir, presently under construction, will soon be operating. The real‐time forecasting of runoff for operational purposes requires simulation of snow accumulation and snowmelt throughout the Basin during the winter season. This article describes capabilities of SNOSIM, a model being developed for performing such simulation. The application of this model as part of a comprehensive system of water control software, and some initial simulation results are presented.
LIMITATIONS OF CONCEPTS USED TO DETERMINE INSTREAM FLOW REQUIREMENTS FOR HABITAT MAINTENANCE1
Authors: Bleed Ann Salomon
Published: June 2007

ABSTRACT: Today most rivers are not freely flowing but are highly regulated to meet both human and wildlife needs. Several models allow the determination of instream flows that are needed to meet wildlife demands. However, these models are based on assumptions that limit their applicability to certain types of rivers. While these limitations do not preclude the use of the models on other types of rivers, like the Platte River in Nebraska, their limitations should be considered and accommodated by those making instream flow planning and management decisions. Other factors affecting channel morphology and its associated wildlife habitat, such as threshold values and vegetation are not adequately considered by current concepts. If rivers are to be managed to provide wildlife habitat, these factors will have to be addressed.
ESTIMATING THE WATER RESOURCE FOR A HIGH SIERRA WATERSHED1
Authors: Guthe William G. , Shelton M. L.
Published: June 2007

ABSTRACT: Competition for water, concerns for maintaining ground water quality, and compliance with legislative action require quantification of the water resource for high elevation watersheds in the Sierra Nevada. However, meager hydroclimatic data frequently hinder runoff assessments needed for formulating water development policies, and the selection of watershed models for estimating the water resource is limited to those requiring a minimum of observational data. A climatic water budget model and an energy slope and aspect model are employed to estimate the water resource for a small watershed in Sierra Valley north of Lake Tahoe. The models employ different assumptions and computational procedures, but the total water available estimated by both models is very similar. Measured runoff is estimated satisfactorily by the models, but streamflow is not representative of the total water resource because a substantial portion of the available water enters the regional ground water system. This conclusion is supported by hydrologic and geochemical evidence, and ground water recharge is estimated to be at least as great as measured runoff during dry years and nearly twice as large during wet years.
GRADUATE EDUCATION IN WATER RESOURCES: AN INNOVATIVE APPROACH Part II: Post‐Production Techniques1
Authors: Welford Virginia C. , Block Richard A. , Bulkley Jonathan W.
Published: June 2007

ABSTRACT: The production of a documentary video in a graduate seminar offers advantages over the traditional term paper. These advantages derive from the nature of the videotape medium. The most distinct difference between a written document and a video production is the use of the video camera to record events. In using the camera, the student is required to become involved both in front of the video camera, for example, as an interviewer, and behind the camera as a camera operator. Next, as an editor, the student is required to review the events that she/he has taped for inclusion in the final product. By participating in these three roles, the student has the opportunity to learn interviewing skills while interacting with professionals in the field, to learn videotaping skills, and to see him/herself as he/she appears to others. The student can use the video feedback to improve his/her professional presentation; posture, dress, gestures, speech, and facial expressions all have an impact on how we are perceived by others. Additionally, the painstaking process of reviewing the taped material leads to an intimate knowledge of the topic, and the process of choosing portions out of entire interviews hones the ability to select the crucial or central themes and ideas from any discussion. Finally, the power of video lies in its ability to communicate information to a wide audience. Although the nature of video for the general public does not permit highly detailed or rigorous coverage of any topic, it is a major source of information. Accordingly, video is an important tool that can be used to inform the public about the importance of wise water resource management.
THE BISCAYNE AQUIFER CONTAMINATION: CLEANUP AND PREVENTION1
Authors: Singh Udai P. , Orban James E.
Published: June 2007

ABSTRACT: The Biscayne Aquifer is the sole source of drinking water for approximately three million residents of southeast Florida. Nine hazardous waste sites on the EPA National Priority List overlie this aquifer. Extensive investigation of an 80 square‐mile area in metropolitan Miami detected low to moderate levels of toxic contaminants in the ground water, with volatile organic chemicals the most prevalent. The Centers for Disease Control concluded that contamination of the aquifer within the study area poses a serious potential threat to public health. Recommendations for source control and cleanup have been partially carried out. The top few feet of soil at the Miami Drum site have been excavated and relocated; ground water encountered during excavation has been withdrawn and treated, and the Northwest 58th Street Landfill has been closed. Recovery and treatment of ground water from the contaminated area was the recommended cleanup measure and has been approved by EPA and state and local agencies. A preventive action program for the Biscayne Aquifer region was also recommended for implementation by local agencies. This program consists of regulations, waste management practices, construction and treatment guidelines, and public information activities and materials. Implementing this program will help keep the Biscayne Aquifer water drinkable far into the future.
USE OF HISTORIC FLOOD INFORMATION IN ESTIMATING FLOOD PEAKS ON UNGAGED WATERSHEDS1
Authors: Wall D. J. , Kibler D. F. , Hastings M. E.
Published: June 2007

Regional procedures to estimate flood magnitudes for ungaged watersheds typically ignore available site‐specific historic flood information such as high water marks and the corresponding flow estimates, otherwise referred to as limited site‐specific historic (LSSH) flood data. A procedure to construct flood frequency curves on the basis of LSSH flood observations is presented. Simple inverse variance weighting is employed to systematically combine flood estimates obtained from the LSSH data base with those from a regional procedure to obtain improved estimtes of flood peaks on the ungaged watershed. For the region studied, the variance weighted estimates of flow had a lower logarithmic standard error than either the regional or the LSSH flow estimates, when compared to the estimates determined by three standard distributions for gaged watersheds investigated in the development of the methodology. Use of the simple inverse variance weighting procedure is recommended when “reliable” estimates of LSSH floods for the ungaged site are available.
STREAM TEMPERATURE INCREASES AND LAND USE IN A FORESTED OREGON WATERSHED1
Authors: Beschta Robert L. , Taylor R. Lynn
Published: June 2007

ABSTRACT: The Salmon Creek Watershed drains 325 km2 of forested terrain in the Cascade Mountains of western Oregon. Over a 30–year period (from 1955 to 1984) average daily maximum and minimum stream temperatures, calculated from the 10 warmest days of each year, have risen 6°C and 2°C, respectively. In contrast, a small decrease in maximum air temperatures was found over the same period. Regression analysis indicated a highly significant (p < 0.01) relationship between a cumulative index of forest harvesting and maximum stream temperatures. Maximum temperatures also tended to increase for several years following major peak flow events. The interaction between harvest activity (logging and road construction), changing forest and riparian management practices and the occurrence of natural hydrologic events (peak flows and associated mass soil movements) tend to obscure specific cause‐and‐effect relationships regarding long‐term changes in maximum stream temperature.
OPTIMAL GROUND WATER MANAGEMENT IN TWO‐AQUIFER SYSTEMS1
Authors: Lindner Wulf , Lindner Klaus , Karadi Gabor
Published: June 2007

ABSTRACT; This paper presents a numerical model for the prediction of optimal ground water withdrawal from a two‐aquifer system by observing a set of constraints determined by the ecological conditions of the ground water basin. The aquifer system consists of an upper unconfined and a lower confined aquifer with a leaky stratum between them. It is assumed that water is withdrawn from the confined aquifer only, but the unconfined aquifer will also be affected due to the leakiness of the layer separating the upper and lower aquifers. Simulation and linear programming are employed for developing a computer model for the optimal management of such systems, with the objectives of determining withdrawal rates for predetermined ground water levels.
RELATIONSHIP BETWEEN ANNUAL RUNOFF AND WATERSHED AREA FOR THE EASTERN UNITED STATES1
Authors: Rochelle Barry P. , Church M. Robbins , Gebert Warren A. , Graczyk David J. , Krug William R.
Published: June 2007

ABSTRACT: As part of the U.S. Environmental Protection Agency's effort to determine the long‐term effects of acidic deposition on surface water chemistry, annual runoff was estimated for about 1000 ungaged sites in the eastern U.S. using runoff contour maps. One concern in using contour maps was that a bias may be introduced in the runoff estimates due to the size of the 1000 ungaged sites relative to the size of the watersheds used in developing the maps. To determine if a bias was present the relationship between the annual runoff (expressed as depth) and the watershed area for the Northeast (NE) and Southern Blue Ridge Province (SBRP) was tested using five regional data bases. One short‐term data base (1984 Water Year, n = 531) and two long‐term data bases (1940–57, n = 134 and 1951–80, n = 342) were used in the NE. In the SBRP one short‐term database (1984 Water Year, n = 531) and one long‐term data base (1951–80, n = 60) were used. For the NE and the SBRP, runoff was not directly correlated with watershed area using the five regional databases. Also, runoff normalized by precipitation was not related to watershed area.
PATTERNS AND TRENDS IN IRRIGATION EFFICIENCY1
Authors: Thompson Stephen A.
Published: June 2007

ABSTRACT: Irrigated agriculture is one of the most important water‐use sectors in terms of total water diversion and consumptive use. For at least the last 25 years, improving irrigation efficiency has been a widely advocated and accepted goal. This paper uses a sample of 16 Bureau of Reclamation irrigation projects to examine the pattern of average irrigation efficiency and change in efficiency over time. In general, the highest average efficiencies are found in the arid Southwest while the lowest are found in the semi‐arid to sub‐humid Great Plains region. Over the 22‐year period of analysis, there has been no observable trend toward improvement in efficiency at any of the projects.
IMPACT OF NONCHLORINATED SECONDARY AND TERTIARY EFFLUENTS ON WARM WATER FISH COMMUNITIES1
Authors: Paller M. H. , Heidinger R. C. , Lewis W. M.
Published: June 2007

ABSTRACT: The fish communities in three sewage receiving Illinois streams were monitored by electrofishing as treatment changed from secondary with chlorination to secondary without chlorination to tertiary without chlorination over a 40‐month period. Degradation of the fish communities was severe during the secondary treatment/chlorination period. When treatment was changed to secondary without chlorination, strong improvements occurred in the fish communities of all streams, and degradation could no longer be demonstrated on the basis of species number. The onset of tertiary treatment resulted in few additional changes in the fish communities, with the possible exception of increased abundance of several species of minnows. Tertiary treatment consisted of nitrification, sand filtration, and, in two streams, phosphorus removal.
EFFECTS OF VARIABLE DISCHARGE SCHEMES ON DISSOLVED OXYGEN AT A HYDROELECTRIC STATION1
Authors: Mathur Dilip , McClellan Eric S. , Haney Susan A.
Published: June 2007

ABSTRACT: The effects of variable discharges during the summer on the dissolved oxygen (DO) content and water temperature upstream and downstream of the Conowingo Hydroelectric Power Station were investigated. The DO dynamics are controlled primarily by meteorological factors that are independent of the mode of hydrostation operation. DO stratification occurred during the summer in Conowingo Pond, but thermal stratification was not observed. The magnitude and duration of off‐peak discharges including a run‐of‐the‐river operation did not affect DO stratification in Conowingo Pond; little vertical mixing occurred. However, strong winds and/or high river flows temporarily destroyed DO stratification. The run‐of‐the‐river operation or off‐peak continuous discharge schemes did not provide better DO conditions downstream of the hydrostation than the peaking operation with intermittent off‐peak releases.

A statistical model predicted that a DO of 5 ppm occurs 0.6 miles downstream of the powerhouse when the natural river flow is consistently greater than 15,000 cfs and water temperature is less than 80°F. A mean daily DO of at least 4 ppm was predicted to occur over 80 percent of the time during the 92‐day summer period. Farther downstream (1.3 miles from the powerhouse) a mean daily DO of at least 4 ppm was predicted to occur 90 percent of the time in summer.
AN ALTERNATIVE TO WATER POLLUTION CONTROLS1
Authors: Chadderton Ronald A.
Published: June 2007

ABSTRACT: A hypothetical, although realistic, water pollution problem was studied from a property rights viewpoint. Theoretical and economic justifications were developed. A fully‐liable, private owner was found to be financially profitable while improving the water quality and providing recreational potential. The example confirmed that property rights provides an answer to stream pollution problems, but contradicted the view that water pollution control must be justified by recreational benefits.
PRIORITIZING WATER MANAGEMENT PROJECTS IN SOUTHEAST ASIA: AN EXPERIMENTAL METHODOLOGY
Authors: McLoughlin Peter F. M.
Published: June 2007

ABSTRACT: Southeast Asian nations with extensive water management systems have numerous candidate and ongoing programs and projects. They cannot possibly all be funded and implemented simultaneously in any serious way. Choices must be made. But how to select? What criteria can assist with the screening in an acceptable manner, particularly in the near absence of useful technical and economic information across them all. This paper suggests a methodology by which assessment criteria can be constructed which conforms to any given national information base and development needs. Criteria can be weighted one against the other in their relative importance. For each criterion a ranking scale puts the “best” (most, highest) at one end and the “worst” (least, lowest) at the other. Each candidate project is then subjected to these consistent assessment methods for a weighted “score.” Key criteria normally have surrogate measures depending on information available. Criteria are of three sorts: sheer volume, e.g., of a specific use, a benefit; ratios and relations, e.g., A as percent of B; and other more subjective criteria, e.g., regional or income distribution impacts. The basic criteria include, for example, time to full benefits (minimize), OM & R as percent of investment (minimize), and permanent rural jobs created (maximize).
“Applicability of the t‐Test for Detecting Trends in Water Quality Variables,” by Robert H. Montgomery and Jim C. Loftis2
Authors: Helsel Dennis R. , Hirsch Robert M.
Published: June 2007

Montgomery and Loftis (1987) have listed several situations for which the t‐test does not accurately reproduce Type I errors, and should therefore be avoided. Characteristics common to water quality data (skewness or other non‐normality, presence of outliers and less‐thans) also reduce the power of the t‐test, in relation to nonparametric alternatives.

Thus if one is interested in reaching correct decisions when trends or differences exist, and not just when they do not, the t‐test should not be considered “robust” (in the sense of being generally applicable) when its assumptions are violated. Further, t‐tests assume that differences in means are relevant (the mean is a good measure of central tendency), and that data groups differ by some additive amount. When all of these assumptions are recognized, and in light of the availability of truly robust and comparatively powerful non‐parametric alternatives, we believe there is little applicability of the t‐test for detecting trends or differences in water quality variables.
TRENDS IN LEAD CONCENTRATIONS IN MAJOR U.S. RIVERS AND THEIR RELATION TO HISTORICAL CHANGES IN GASOLINE‐LEAD CONSUMPTION1
Authors: Alexander Richard B. , Smith Richard A.
Published: June 2007

ABSTRACT: Declines in concentrations of dissolved lead occurred at nearly two‐thirds of 306 locations on major U.S. rivers from 1974 to 1985. Declines in dissolved lead concentrations are statistically significant (p < 0.10) at approximately one‐third of the sampling locations. Statistically significant increases in dissolved lead concentrations occurred at only 6 percent of the sites, but are clustered in the Texas‐Gulf and Lower Mississippi regions. Possible explanations for the observed trends in lead concentrations are tested through comparisons with (1) records of lead discharges from major sources including leaded‐gasoline consumption and municipal‐ and industrial‐point source discharges, (2) trends in various water‐quality constituents such as pH and total alkalinity, and (3) basin characteristics such as drainage area. Statistically significant declines in lead concentrations in streams and gasoline lead (i.e., the largest source of lead at these sites) are highly coincident for the 1979 to 1980 period at most sampling locations. The greatest amount of decline in gasoline lead occurred at sites showing statistically significant downtrends in stream concentrations of lead from 1974 to 1985. No more than 5 percent of the trends in stream lead are influenced by municipal‐ and industrial‐point sources of lead. Factors that affect the transport of dissolved lead, including lead solubility, suspended sediment, and basin characteristics such as drainage basin size, are not significantly related to trends in dissolved lead. Trends in streamflow explain no more than 7 percent of the downtrends in concentrations of lead and may partly explain the frequent increases in lead concentrations in the Texas‐Gulf and Lower Mississippi regions.
EFFECTS OF RATE STRUCTURE KNOWLEDGE ON HOUSEHOLD WATER USE1
Authors: Agthe Donald E. , Billings R. Bruce , Dworkin Judith M.
Published: June 2007

ABSTRACT: Socioeconomic determinants of individual household water use were estimated using regressions of these characteristics with actual household water use for winter and summer. Results were disaggregated between those consumers who were aware of an increasing block rate price structure and those who were not. Most of the informed group members believed that this price structure did result in significant reductions in water use. Nevertheless, overall water use was greater for the informed group. The determinants of water use were found to differ between informed and uninformed users as well as between winter and summer. The uninformed users were influenced by a larger set of variables in each season than the informed group. In winter, the informed group members with swimming pools and/or arid landscaping used less water than their uninformed counterparts. Summer water use increased with length of tenancy in home for the uninformed group but not for informed, while increasing with ownership for informed consumers.
PLANNITG INDIANA'S WATER INFRASTRUCTURE FROM A COMPETITIVE PERSPECTIVE1
Authors: Houck Mark H. , Wright Jeff R. , Diamond James T. , Toft Graham
Published: June 2007

ABSTRACT: Indiana has embarked on a program to assess the condition of its infrastructure and to plan for its future. The perspective of this planning differs from the traditional “master plan” approach — instead, the focus is on competitiveness for economic development. The initial work on the water and sewerage competitiveness of the infrastructure includes: (1) a comparative analysis of the water resources and infrastructure of Indiana and its industrial midwestern neighbors; (2) a technology scan to identify possible technological opportunities that may be important for Indiana; and (3) a set of recommendations for future planning. This work is preliminary in nature but should serve as a starting point for continued strategic planning over the next decade for positioning of Indiana's water and sewerage infrastructure as a key element in the economic growth equation.
SATURATED SOIL HYDRAULIC CONDUCTWITY IN LOBLOLLY PINE PLANTATIONS ON DRAINED SITES1
Authors: Nelson Paul A. , Gregory James D.
Published: June 2007

ABSTRACT: Variation of in situ measured saturated hydraulic conductivity (KS) with stand age was examined in drained and intensively managed loblolly pine (Pinus taeda L.) plantations on very poorly drained Bayboro loam soils. Stand ages studied were 1‐year‐old and 14‐years old. No differences in Ks values were found between the stand ages. In addition, no differences in core measured soil properties were found between the stand ages, indicating that there were no differences in the pore structure of the soil matrix. There was large variation of Ks within stands and between stands within ages. The mean within stand Ks values ranged from 0.66 cm/hr to 4.85 cm/hr. The frequency of tests exhibiting pipe flow through large non‐capillary voids was significantly greater in the older stands; however, the continuity of the voids in the soil, and whether or not non‐Darcy type flow would occur in a saturated profile, could not be determined.
MULTIOBJECTWE ALLOCATION OF WATER SHORTAGE IN THE SVARTA RIVER, SWEDEN1
Authors: Goulter I. C. , Castensson R.
Published: June 2007

ABSTRACT: A model is proposed for allocation of water shortages among competing water uses in the Svarta River basin in Sweden. The three major competing uses in the basin are hydroelectricity generation, irrigation water supply, and urban water supply. Minor uses that impact upon the allocation are minimum river flow requirements for fishlife and for dilution of treated wastewater, and storage level restrictions for recreation purposes in the main storage facility, Lake Sommen. Analysis of the competing demands on the water are modeled through the method‐of‐weights multiobjective technique using a deterministic mixed‐integer optimization formulation. The (0–1) variables in the formulation are required to synthesize the restricted validity of permits for withdrawal of irrigation water from the river and to simulate the complex operating rules of the major regulation facility on the river. Due to the deterministic nature of the formulation, the model is used on a hydrologic scenario basis. Use of the model is demonstrated by application to the Svarta River.
MUNICIPAL RESPONSES TO VOLATILE ORGANIC COMPOUNDS IN WISCONSIN GROUND WATER1
Authors: Page G. William
Published: June 2007

ABSTRACT: Contamination of ground water supplies with volatile organic compounds is a new and significant problem. Municipalities and their community water systems are often the first to discover ground water contamination because of the monitoring programs they are required to carry out. When contamination exceeds standards, some action is required.

The responses of Wisconsin municipalities to volatile organic compounds that exceed standards in their ground water sources is described. Actions to protect human health are prompt, but the survey results indicate plumes of contaminated ground water are usually not treated. They may continue to migrate and contaminate other private and public wells.
OPTIMIZING THE RETURN FROM A JOJOBA PLANTATION UNDER SCARCE DATA CONDITIONS1
Authors: Wisniak Daniel , Oron Gideon
Published: June 2007

ABSTRACT: There is a serious shortage of yield data for Jojoba (SIMMONDSIA CHINENSIS) from mature and cultivated plantations of ten years or older. Thus, the optimal quantities of water and fertilizers that are needed annually by a Jojoba plantation to achieve maximum profits were estimated from existing plantations.

A computer model (IMSL subroutine ZXMWD) was used to determine a Mitscherlich yield function. An economic profit model that incorporates the yield function was then designed to maximize the profits. According to the net present value (NPV) criterion, the maximum yearly net profit is about $7800 per ha, which is achieved during the 11th growth year. The computed cumulative NPV is approximately $21,000 per ha for the entire 15‐year period. Similar profits were calculated when the model was tested to examine the NPV using different assumptions with respect to varying costs.
RELIABILITY‐BASED DESIGN CONCEPTS IN HYDRAULIC ENGINEERING1
Authors: Plate Erich J. , Duckstein Lucien
Published: June 2007

ABSTRACT: Different probability‐based concepts for design of hydraulic structures are presented that could replace or complement traditional designs based on the concept of design load plus a safety margin. The traditional concept (here called Level I design) does not permit the assignment of the correct probability to the failure event. Concepts which are based on the correct probability of failure are based on descriptions of resistance and load as random variables. Level II design assumes these random variables to be Gaussian distributed. Level III is based on arbitrary distributions of load and resistance. Level II and III concepts are appropriate for evaluation of a design's reliability. Design Level IV is also based on the joint probability density function for loads and resistances; in addition, it requires the assignment of a consequence function to each combination of resistance and loads. The design concepts are illustrated with the design of a flood levee on a river.
VARIABILITY OF SOIL WATER PROPERTIES AND CROP YIELD IN A SLOPED WATERSHED1
Authors: Naney J. W. , Williams R. D. , Ahuja L. R.
Published: June 2007

ABSTRACT: Spatial distribution of soil and water properties and the correlations between them and crop yield were determined for a natural rainfall environment. Hydraulic conductivity, soil texture, water retention, and soil‐water flux were variables used to investigate their relationship to crop yield using multiple regression techniques. Variations in crop yields on a watershed with a 3 to 4 percent slope and moderately erosive soils were related to soil‐water characteristics and soil properties along slope and with depth. Climatic conditions to sustain crop growth and yield ranged from inadequate soil water in 1983 to adequate soil water in 1984. Crop yield was predicted with models using both available and measured soil‐water content. Available water content provided a better model for the prediction of water yield and does not require field measurements of actual soil‐water content. Soil water holding capacity was more significant for predicting crop yield in soils with moderate to high silt content than infiltrability of water into the soil.
WETLAND BOUNDARY DETERMINATION IN THE GREAT DISMAL SWAMP USING WEIGHTED AVERAGES1
Authors: Carter Virginia , Garrett Mary Keith , Gammon Patricia T.
Published: June 2007

ABSTRACT: A weighted average method was used to analyze transition zone vegetation in the Great Dismal Swamp to determine if a more uniform determination of wetland boundaries can be made nationwide. The method was applied to vegetation data collected on four transects and three vertical layers across the wetland‐to‐upland transition zone of the swamp. Ecological index values based on water tolerance were either taken from the literature or derived from local species tolerances. Wetland index values were calculated for 25‐m increments using species cover and rankings based on the ecological indices. Wetland index values were used to designate increments as either wetland, transitional, or upland, and to examine the usefulness of a provisional wetland‐upland break‐point. Most increments were designated wetland or transitional when all species were used. Removal of three or five ubiquitous species either gave a wider range of wetland index values with a more variable designation of increments or caused designation of increments to be similar for all layers. The use of locally‐derived rankings showed the sensitivity of the weighted averages method to ecological indices of species with large importance values. The weighted average method did not provide for an objective placement of an absolute wetland boundary, but did serve to focus attention on the transitional boundary zone where supplementary information is necessary to select a wetland‐upland breakpoint.
CALIBRATION OF A WATER‐BALANCE MODEL FOR SMALL WATERSHEDS IN EASTERN OREGON1
Authors: Higgins D. A. , Maloney S. B. , Tiedemann A. R. , Quigley T. M.
Published: June 2007

ABSTRACT: The BURP water‐balance model was calibrated for 13 small (0.46 to 7.00 mi2), forested watersheds in the Blue Mountains of eastern Oregon where snowmelt is the dominant source of runoff. BURP is the model name and is not an acronym. Six of the 16 parameters in BURP were calibrated. The subsurface recession coefficient and three subsurface water‐storage parameters were most sensitive for simulating monthly flow. Calibrated subsurface recession coefficients ranged from 0.988 to 0.998. The subsurface‐water storage parameters were calibrated at between 20 to 120 percent of their initial values obtained from a category III soil survey. That reconnaissance‐level survey was apparently too broad to accurately reflect subsurface‐water storage in small watersheds. Tests of model performance showed BURP is capable of producing accurate simulations of monthly flow for mountainous, snow‐dominated watersheds with shallow (< 4 ft) soils when calibrated with 2 to 4 years of streamflow data. A regression of observed versus simulated monthly flows with data from all watersheds combined showed that BURP accounted for 85 percent of the variability in observed flows, which ranged from 0.01 to 20.8 inches, but underpredicted high flow months, with a slope of 1.15 that is significantly different from 1.0 (p = 0.05). Without prior calibration, subsurface‐water storage parameters appeared to be the greatest source of potential error.
A SIMPLE TECHNIQUE FOR ESTIMATING ABSORPTION AND SCATTERING COEFFICIENTS1
Authors: Effler Steven W. , Roop Russell , Perkins Mary Gail
Published: June 2007

ABSTRACT: Results from five different test systems, which include a wide range of optical conditions, indicate credible estimates of the values of the absorption and scattering coefficients can be calculated from paired measurements of Secchi disc transparency and the diffuse attenuation coefficient. The diagnostic utility of the estimates in identifying components and processes that regulate light penetration is demonstrated for three different cases. The simple estimation technique is valuable in the analysis of existing data bases that lack comprehensive optical information to develop and evaluate alternate models for light penetration and to establish the experimental needs of future field programs to support lake management efforts.
A SEPARABLE LINEAR ALGORITHM FOR HYDROPOWER OPTIMIZATION1
Authors: Ellis J. Hugh. , ReVelle Charles S.
Published: June 2007

ABSTRACT: A deterministic, separable, linear algorithm is presented for maximizing aggregate hydropower production. The method is iterative and amenable to solution using standard LP software. The utility of the technique is demonstrated using several test applications involving a hypothetical single‐purpose hydropower reservoir and a monthly increment 20‐year flow record from the Gunpowder River in Maryland. The separable linearized forms solved quickly using MPSX on a variety of IBM hardware: 3090‐400 VF, 3084 QX, dual processor 4381‐3, and an AT/370 personal computer. For comparison purposes, the original nonlinear nonseparable version of the model was also solved using MINOS. This yielded a value of aggregate hydropower marginally higher than that using MPSX. The separable, linearized methodology proved to be a useful and an efficient means of generating good starting points for MINOS. The use of these warm starts effected substantial reductions in MINOS execution times.