bluuebunny/crossref_metadata_2025 huggingface dataset:
THE POLITICAL ECONOMY OF AGRICULTURE, GROUND WATER QUALITY MANAGEMENT, AND AGRICULTURAL RESEARCH1
Authors: Roberts Rebecca S. , Lighthall David R.
Published: June 2007

ABSTRACT: The growing problem of nonpoint source ground water contamination from agricultural chemicals is conceptualized as an historical outcome of the production environment of capitalist agriculture in the Corn Belt. Chronic overproduction and ground water contamination reveal different aspects of the same technological treadmill. The debate over Iowa's 1987 Ground Water Protection Act symbolizes the contradiction between popular demand for clean water and structural limits on policymaking. Although the Act does provide for expanded research, education, and monitoring, a coalition of commercial farmers, local chemical dealers, and the national chemical industry defeated a tax on pesticide use. Analysis of alternate policy responses ‐ Best Management Practices (BMPs), cross compliance, site‐specific regulation of chemical use, and taxation of synthetic chemicals ‐ reveals that all tend to founder on the same structural constraints. Without practical, profitable, low‐input technologies that farmers, over time, would choose to adopt, both voluntary and regulatory approaches encounter major political or implementation difficulties. The public agricultural research agenda, therefore, emerges as a central control variable for ground water quality management and a central focus for political struggle.
WOODY VEGETATION AND RIPRAP STABILITY ALONG THE SACRAMENTO RIVER MILE 84.5–1191
Authors: Shields F. Douglas
Published: June 2007

ABSTRACT: Stability of vegetated and bare riprap revetments along a Sacramento River reach during the flood of record was assessed. Revetment damages resulting from the flood were identified using records provided by the U.S. Army Corps of Engineers and verified by contacts with local interests. Vegetation on revetments along a 35.6‐mile reach was mapped using inspection records and stereo interpretation of aerial phoths taken shortly before and after the flood. A follow‐up field inspection was conducted in September 1989. Revetment age, material, bank curvature, vegetation, and damage were mapped from a boat. Mapping results from both 1986 and 1989 were placed in a data base. About 70 percent of the bank line of the study reach was revetted. About two‐thirds of the revetment was cobble; one‐third was quarry stone. Revetment vegetation varied from none to large (> 50‐inch diameter) cotton‐woods. About 10 percent of the revetted bank line supported some type of woody vegetation. Damage rates for revetments supporting woody vegetation tended to be lower than for unvegetated revetments of the same age located on banks of similar curvature. Chisquared tests indicated damage rates were greater for older (pre‐1950 construction) revetments, but were unable to detect differences based on vegetation or bank curvature. Research is needed to generate design criteria and construction techniques to allow routine use of woody plants in bank protection structures.
THE APPLICABILITY OF MORTON'S AND PENMAN'S EVAPOTRANSPIRATION ESTIMATES IN RAINFALL‐RUNOFF MODELING1
Authors: Chiew F H. S. , McMahon T A.
Published: June 2007

ABSTRACT: Estimates of the upper constraint on actual evapotranspiration are required as input data in the majority of rainfall‐runoff models. This paper compares and discusses the applicability of Penman's potential evapotranspiration estimates and Morton's wet environment evapotranspiration estimates in rainfall‐runoff modeling applications. Morton's wet environment evapotranspiration depends only on the atmospheric variables and is the estimate of evapotranspiration that would occur when water supply is not limiting. It is a conceptually more correct representation of the upper constraint on actual evapotranspiration compared to Penman's potential evapotranspiration which is dependent on the water supply to the soil‐plant surfaces. Although Penman's potential evapotranspiration and Morton's wet environment evapotranspiration are two different quantities, comparison of the two estimates using data from different climatic regions throughout Australia indicate that they provide similar magnitudes of the upper limit of actual evapotranspiration at moderate climatic conditions when reliable estimates are required in rainfall‐runoff models. The two estimates can therefore be used interchangeably in rainfall‐runoff modeling applications.
A CASE STUDY OF SHALLOW FLOW PATHS IN A STEEP ZERO‐ORDER BASIN1
Authors: McDonnell J. J. , Owens Ian F , Stewart M. K.
Published: June 2007

ABSTRACT: Soil water potentials, slope throughflow, runoff chemistry, and isotopic composition were monitored in a 97 m2 zero‐order basin within the Maimai 8 watershed on the South Island of New Zealand, for a natural rain storm and two artificial water applications. Contrary to results previously reported for other portions of the Maimai catchment, much of the runoff occurred as a shallow subsurface organic layer flow. For the 47 mm natural rain event, pre‐storm soil matric potential ranged from −60 to −150 cm H2O. No saturation was produced within the profile, and the majority of storm runoff emanated from flow within the organic horizon perched on the mineral soil surface. Hillslope applications corroborated this interpretation by showing >90 percent new water flushing with negligible mineral soil moisture response. Although the mechanisms cited in the text are not representative of the entire catchment, the study demonstrates: (1) the value of a combined physical‐chemical‐isotopic approach in quantifying slope processes, and (2) the heterogeneous nature and diversity of slope runoff pathways in a relatively homogeneous catchment.
A SENSITIVITY ANALYSIS OF THE PALMER HYDROLOGIC DROUGHT INDEX1
Authors: Guttman Nathaniel B.
Published: June 2007

ABSTRACT: The sensitivity of the Palmer Hydrologic Drought Index to departures from average temperature and precipitation conditions is examined. A time series of zero index values was calculated and then one monthly temperature or precipitation value was perturbed. The resulting time series shows the effects on the index of one anomalous value. Independent series were calculated for temperature anomalies of plus and minus 1, 3, 5, and 10F and for precipitation anomalies of 25, 50, 75, 125, 150, and 200 percent of normal for each calendar month for Colorado, Indiana, Nevada, New York, Oklahoma, South Carolina, South Dakota, Washington, and Wisconsin.

Analysis of the time series showed that the period of time required for the index to reflect actual rather than artificial initial conditions could be more than four years. It was also found that the effects of temperature anomalies are insignificant compared to the effects of precipitation anomalies. In some cases, one anomalous precipitation value could result in established wet or dry spells that last for up to two years. Although not examined in detail, the time series suggest that distributions of index values may be asymmetrical and possibly bimodal.
FLOOD FREQUENCY ANALYSIS FOR EVALUATING WATERSHED CONDITIONS WITh RAINFALL‐RUNOFF MODELS1
Authors: Bradley A. Allen. , Potter Kenneth W.
Published: June 2007

ABSTRACT: Many rainfall‐runoff modeling studies compare flood quantiles for different land‐use and/or flood mitigation scenarios. However, when flood quantiles are estimated using conventional statistical methods, comparisons may be misleading because the estimates often misrepresent the quantile relationship between scenarios. An alternate statistical procedure is proposed, in which rainfall‐runoff modeling is used to evaluate an approximate relationship between flood quantiles for different scenarios. Monte Carlo experiments show that the proposed method produces flood quantile estimates that better reflect the differences between scenarios. The ratio between quantiles for different scenarios is more accurate, so comparisons of the scenarios using flood quantiles are more reliable.
VARIABILITY OF BOTTOM SEDIMENT CHARACTERISTICS OF THE CONTINENTAL UNITED STATES1
Authors: Suedel Burton C. , Rodgers John H.
Published: June 2007

ABSTRACT: Sediment characteristics of samples from physiographic provinces of the continental United States were examined to determine variability within and among physiographic provinces and to compare characteristics of freshwater and saltwater sediments. Organic carbon, particle size distribution, particle surface area, cation exchange capacity, redox potential, and percent solids were examined for a variety of lotic and lentic freshwater sediment samples and nearshore estuarine and marine samples from the continental United States. Analysis of variance indicated significant differences (p < 0.05) within and among physiographic provinces for both freshwater and saltwater sediment samples. Sediment characteristics within physiographic provinces were as variable as characteristics among provinces. Freshwater sediment characteristics were not significantly different (p < 0.05) from saltwater sediment characteristics. Saltwater sediment characteristics were observed to be more strongly correlated with each other than were freshwater sediment characteristics. Based on the variability of sediment samples examined in this study, a specific site may require 50 or more replicate samples to be adequately or accurately represented.
MONTHLY RUNOFF DISTRIBUTION RELATED TO BASIN GEOGRAPHY1
Authors: Copp Howard D.
Published: June 2007

ABSTRACT: Mean monthly runoff from ungaged drainage basins that have significant snowpacks each year can be estimated quite well by assuming that the time duration between snowfall and snowmelt is the predominant factor in temporal runoff distribution. That time span is related to basin temperatures which are, in turn, functions of basin elevation and latitude. Regional hydrologic analyses of gaged basin data create regression equations for estimating runoff distribution by month. These equations then can be applied to ungaged basins. Basin latitude and mean elevation are two independent variables that can be used in estimating monthly runoff distributions.
ENVIRONMENTAL IMPACT MITIGATION UNDER THE CLEAN WATER ACT AND THE NATIONAL ENVIRONMENTAL POLICY ACT: THE CASE OF TWO FORKS DAM1
Authors: Woltemade Christopher J.
Published: June 2007

ABSTRACT: The role of environmental mitigation in permitting decisions under Section 404 of the Clean Water Act and the National Environmental Policy Act is examined, addressing the extent to which compensatory mitigation is acceptable. The role of mitigation is examined both generically and specifically: first in the requirements of the Clean Water Act and NEPA, and then in the case study of the proposed Two Forks Dam. In both cases, the paper describes dual purposes of environmental protection legislation and mitigation: to protect the biophysical environment and maintain associated human values. Mitigation is found to be sometimes necessary and acceptable as compensation for unavoidable impacts of project development. However, the Two Forks case exemplifies that compensatory mitigation has also been employed as a mechanism to facilitate project development when practicable alternatives entailing less environmental impact are available. Acceptance of compensatory mitigation in such cases violates both the Guidelines of the Clean Water Act and the intent of that Act and NEPA to protect the biophysical environment and human welfare. A recent memorandum of agreement between the Corps and the EPA clarifies this policy, and suggests that permit applications which rely on compensatory mitigation when impacts are available may be denied.
RIVER PHOSPHORUS DYNAMICS AND RESERVOIR EUTROPHICATION POTENTIAL1
Authors: Rosensteel Barbara A. , Strom Peter F
Published: June 2007

ABSTRACT: Sediments from the Pompton and Passaic Rivers at Two Bridges were analyzed for potentially available phosphorus fractions and total phosphorus (TP). Water samples from the same sites were analyzed for dissolved phosphorus, TP, suspended solids (SS), and volatile SS. Significant negative correlations between river TP concentrations and flow were observed. However, storm flows resulted in increases in TP and SS concentrations and flux (loadings). Most of the increase in river P loading at high flow was in the dissolved fraction, suggesting that the sediments may be a large source of dissolved P. Concentrations of potentially available P in the sediments ranged from 140 to 1310 times the TP concentration in the overlying water. According to a modified Vollenweider model, current P concentrations in the Pompton and Passaic Rivers will result in excessive P loading in the Wanaque Reservoir if even small volumes of river water are pumped to the reservoir through the recently completed Wanaque South pipeline. Reductions in sewage treatment plant effluent P concentrations alone will not produce sufficient decreases in river phosphorus concentrations to avoid this predicted overloading and eutrophication.
LANDSAT MID‐INFRARED DATA AND GIS IN REGIONAL SURFACE SOIL‐MOISTURE ASSESSMENT1
Authors: Shih Sun F , Jordan Jonathan D.
Published: June 2007

ABSTRACT: Landsat satellite Thematic Mapper (TM) data were used to assess regional soil moisture conditions. The mid‐infrared (MIR) data of TM band 7 were overlain onto four principal land‐use categories (Agricultural/Irrigated, Urban/Clearings, Forest/ Wetlands, Water) using a geographic information system (GIS). M data were used to assess four qualitative surface soil‐moisture conditions (water/very wet, wet, moist, and dry) within each land‐use category of a 208,354 ha southwestern Florida study area. The MIR response was inversely related to the qualitative surface soil‐moisture content. Integration of Landsat TM MIR data with land use through GIS appears to be a useful technique for high‐resolution regional soil moisture assessment, and further research to reline this technique is recommended.
MULTIOBJECTIVE DECISION MAKING TECHNIQUES FOR RESERVOIR OPERATION1
Authors: Harboe Ricardo
Published: June 2007

ABSTRACT: Six applications of multiobjective decision making techniques for finding optimal or satisfying operating rules for reservoir systems are presented. The examples include situations with hydropower vs. water supply (for irrigation), flood control vs. low flow augmentation, selection of an operating rule, low‐flow vs. reliability, and low flow and recreation vs. water quality. The techniques applied include the constraint method, compromise programming, goal programming, Tchebycheff approach (max‐mm), Consensus, and ELECTRE I and II.
OF DOGS AND TAILS: WATER POLICY AND SOCIAL POLICY IN ARIZONA1
Authors: Waterstone Marvin
Published: June 2007

ABSTRACT: The general relationship between water policy and social policy in the Western United States is examined by utilizing the example of the Arizona Groundwater Management Act. Too often, this is a relationship which goes largely unexamined, at least in any explicit way. In areas of perceived or real water scarcity, it is often the case that the setting of water policy severely constrains the social policy. Too many fundamental social policy issues are left to unstated assumptions through such a procedure. But, this paper asks, should not the social policy lead, and the water policy follow? In other words, in this relationship, which is the dog, and which is the tail?
SENSITWITY OF IRRIGATION DEMAND IN A HUMID‐TEMPERATE REGION TO HYPOTHETICAL CLIMATIC CHANGE1
Authors: McCabe Gregory J. , Wolock David M.
Published: June 2007

ABSTRACT: An irrigation model based on a modified Thornthwaite water balance was used to simulate the effects of various hypothetical climatic changes on annual irrigation demand in a humidtemperate climate. The climatic‐change scenarios consisted of combinations of changes in temperature, precipitation, and stomatal resistance of plants to transpiration. The objectives were to (1) examine the effects of long‐term changes in these components of climatic change on annual irrigation demand, and (2) identify which of these factors would cause the largest changes in annual irrigation demand.

Hypothetical climatic changes that only included increases in temperature and changes in precipitation resulted in increased annual irrigation demand, even with a 20 percent increase in precipitation. The model results showed that, for the ranges of changes in temperature and precipitation used in this study, changes in irrigation demand were more sensitive to changes in temperature than to changes in precipitation. Model results also indicated that increased stomatal resistance to transpiration counteracted the effects of increases in temperature and decreases in precipitation on irrigation demand. Changes in irrigation demand were even more sensitive to changes in stomatal resistance than to changes in temperature. A large amount of uncertainty is associated with predictions of future climatic conditions; however, uncertainty associated with natural climatic variability may be larger and may mask the effects of climatic change on irrigation demand.
IMPACT OF SURFACE COAL MINING ON THREE OHIO WATERSHEDS –PHYSICAL CONDITIONS AND GROUND‐WATER HYDROLOGY1
Authors: Bonta J. V. , Amerman C. R. , Dick W. A. , Hall G. F. , Harlukowicz T J. , Razem A. C. , Smeck N. E.
Published: June 2007

ABSTRACT: A study was conducted over a six‐year period in East‐Central Ohio to determine the effects of surface mining and reclamation on physical watershed conditions and on ground‐water hydrology in three ground‐water zones in three small experimental watersheds. Mining disturbances in watersheds adjacent to the experimental sites affected ground‐water levels in the undisturbed experimental watersheds prior to actual mining in the experimental sites. New subsurface flow paths, with different characteristics, formed during mining and reclamation. At all three sites mining dewatered the saturated zone above the underclay of the mined coal seam. Mining and reclamation affected ground‐water levels below the mined coal seam in the middle and lower zones within at least two sites. Ground‐water level recovery in the mined upper saturated zone was slow and irregular both temporally and spatially after reclamation. Hydraulic conductivities of postmining (Phase 3) spoil were generally greater than those of Phase 1 bedrock, but wide spatial variability was observed. Modelers need to be aware of the complexities of new flow paths and physical characteristics of subsurface flow media that are introduced by mining and reclamation, including destruction of the upper‐zone clay.
A SURVEY OF HYDROLOGY COURSE CONTENT IN NORTH AMERICAN UNIVERSITIES1
Authors: Groves James R. , Moody David W.
Published: June 2007

ABSTRACT: This report presents the results of a survey of hydrology faculties of colleges and universities in the United States and Canada. Information is presented on topics covered in classes, allocation of class periods to individual topics, textbooks, prerequisites, computer use, and accreditation categories for hydrology courses offered by engineering departments. Hydrology courses generally require courses in fluid mechanics, mathematics, statistics, and computer science as prerequisites. Topics that receive the largest allocation of time in both introductory and advanced courses include rainfall‐runoff relations, the hydrologic cycle, routing and open channel flow, and statistics. Advanced courses place greater emphasis on watershed models than do the introductory courses. Hydrology courses at both levels allocate the smallest amounts of time to snow hydrology ground‐water hydrology, and “other topics.” Very few courses include field or experimental work. In a discipline where computer modeling is a major tool, this lack of field and data‐collection experience may lead students to underestimate the uncertainties associated with data used to calibrate models and the modeling results themselves.

Survey responses on hydrology courses taught in departments other than civil engineering were too few to permit detailed analysis. Most of these courses spend approximately two‐thirds of available class time on the same topics as presented in engineering hydrology courses. The balance of class time is spent on topics that emphasize the specialized interest of the particular discipline, such as soil physics and soil moisture in agricultural engineering.
AN OBJECTWE TEST FOR HYDROLOGIC SCALE1
Authors: Song Zhida , James L. Douglas.
Published: June 2007

ABSTRACT: Improving the reliability of parametric hydrologic models (sometimes called cenceptual rainfall‐runoff models) in the continuous simulation of runoff from ungaged catchments has been frustrated by difficulties in estimating model parameters from catchment characteristics. An underlying problem is that these models use parameters to represent catchments as a whole, whereas data on catchment characteristics are collected at multiple field locations and are difficult to transform into one measure of collective impact. Subdividing the catchment and calibrating a stochastic parametric model to estimate distributions for the parameters that covered the range of observed streamflow values was found to improve the simulations. This paper presents an optimization of the amount of subdivision to use in simulation with a version of the Stanford Watershed Model using available climatological data. The calibration process assumes that catchment heterogeneity introduces errors that can be reduced by calibrating parameters as spatial distributions rather than single values. Calibrations for three diverse small gaged catchments located in California and in Virginia found the optimal number of subdivisions to range from 4 to 25 and the optimal scale to range from 0.3 to 2.1 mi2.
CHANGING A GREAT CITY IN EASTERN EUROPE — CRACOW: ENVIRONMENTAL CHANGES1
Authors: Pociask‐Karteczka Joanna
Published: June 2007

ABSTRACT: The main factor in the location of medieval Cracow was drainage. In the 700‐year history of the City, there were numerous changes in water conditions, particularly in channel network, runoff, ground water level, and ice phenomena. The most dangerous threat to surface water and ground water in Cracow in the last decades has been from industrial and municipal sewage. Currently there are no rivers that meet Drinking Water Quality standards in Cracow. The quality of the ground water has declined because of infiltration of contaminated river water, water from sewage disposal ponds, and pollution from the atmosphere and soil. Cracow does not have enough waste water plants to meet its needs. Most municipal and industrial sewage has not been treated or has been treated only partially. Because of considerable contamination of surface and ground waters in Cracow, more than half of the city's fresh water is pumped about 50 kilometers from a reservoir on the Raba River. A Polish government declaration of April 4, 1989, recognized Cracow as an area of particular protection, and directed that a number of actions be undertaken for the protection of environmental quality.
HERBICIDE AND NITRATE VARIATION IN ALLUVIUM UNDERLYING A CORN FIELD AT A SITE IN IOWA COUNTY, IOWA1
Authors: Kalkhoff S. J. , Detroy M. G. , Cherryholmes K. L. , Kuzniar R. L.
Published: June 2007

ABSTRACT: A hydrologic investigation to determine vertical and seasonal variation of atrazine, alachlor, cyanazine, and nitrate at one location and to relate the variation to ground‐water movement in the Iowa River alluvium was conducted in Iowa County, Iowa, from March 1986 to December 1987. Water samples were collected at discrete intervals through the alluvial sequence from the soil zone to the base of the aquifer. Alachlor, atrazine, and cyanazine were detected most frequently in the soil zone but also were present in the upper part of the alluvial aquifer. Alachlor was detected sporadically, whereas, atrazine, cyanazine, and nitrate were present throughout the year. In the alluvial aquifer, the herbicides generally were not detected during 1986 and were present in detectable concentrations for only a short period of time in the upper 1.6 meters of the aquifer during 1987. Nitrate was present throughout the alluvium and was stratified in the alluvial aquifer. The largest nitrate concentrations were detected in the middle part of the aquifer. Nitrate concentrations were variable only in the upper 2 meters of the aquifer. Vertical movement of herbicides and nitrate in the soil correlated with precipitation and degree of saturation. A clay layer retarded vertical movement of atrazine but not nitrate from the soil layer to the aquifer. Vertical movement could not account for the chemical variation in the alluvial aquifer.
UNCERTAINTY OF EXTREME FLOOD ESTIMATES INCORPRATING HISTORICAL DATA1
Authors: Stevens Ellen W.
Published: June 2007

ABSTRACT: The ability to predict extreme floods is an important part of the planning process for any water project for which failure will be very costly. The length of a gage record available for use in estimating extreme flows is generally much shorter than the recurrence interval of the desired flows, resulting in estimates having a high degree of uncertainty. Maximum likelihood estimators of the parameters of the three parameter lognormal (3PLN) distribution, which make use of historical data, are presented. A Monte Carlo study of extreme flows estimated from samples drawn from three hypothetical 3PLN populations showed that inclusion of historical flows with the gage record reduced the bias and variance of extreme flow estimates. Asymptotic theory approximations of parameter variances and covariances calculated using the second and mixed partial derivatives of the log likelihood function agreed well with Monte Carlo results. First order approximations of the standard deviations of the extreme flow estimates did not agree with the Monte Carlo results. An alternative method for calculating those standard deviations, the “asymptotic simulation” method, is described. The standard deviations calculated by asymptotic simulation agree well with the Monte Carlo results.
STREAM TEMPERATURE ESTIMATION FROM AIR TEMPERATURE1
Authors: Stefan Heinz G. , Preud'homme Eric B.
Published: June 2007

ABSTRACT: Air temperatures are sometimes used as substitutes for stream temperatures. To examine the errors associated with this procedure, linear relationships between stream temperatures, T, and air temperatures, Ta, recorded for 11 streams in the central U.S. (Mississippi River basin) were analyzed. Weather stations were an average 42 miles (range 0 to 144 miles) from the rivers. The general equations, Tw= 5.0 + 0.75 Ta and Tw= 2.9 + 0.86 Ta with temperatures in °C, were derived for daily and weekly water temperatures, respectively, for the 11 streams studied. The simulations had a standard deviation between measurements and predictions of 2.7°C (daily) and 2.1°C (weekly). Equations derived for each specific stream individually gave lower standard deviations, i.e., 2.1°C and 1.4°C, respectively. Small, shallow streams had smaller deviations than large, deep rivers. The measured water temperatures follow the air temperatures closely with some time lag. time lags ranged from hours to days, increasing with stream depth. Taking into account these time lags improved the daily temperature predictions slightly. Periods of ice cover were excluded from the analysis.
EFFECTS OF AGRICULTURAL NUTRIENT MANAGEMENT ON NITROGEN FATE AND TRANSPORT IN LANCASTER COUNTY PENNSYLVANIA1
Authors: Hall David W. , Risser Dennis W.
Published: June 2007

ABSTRACT: Nitrogen inputs to, and outputs from, a 55‐acre site in Lancaster County, Pennsylvania, were estimated to determine the pathways and relative magnitude of loads of nitrogen entering and leaving the site, and to compare the loads of nitrogen before and after the implementation of nutrient management.

Inputs of nitrogen to the site were manure fertilizer, commercial fertilizer, nitrogen in precipitation, and nitrogen in ground‐water inflow; and these sources averaged 93, 4, 2, and 1 percent of average annual nitrogen additions, respectively. Outputs of nitrogen from the site were nitrogen in harvested crops, loads of nitrogen in surface runoff, volatilization of nitrogen, and loads of nitrogen in ground‐water discharge, which averaged 37, less than 1, 25, and 38 percent of average annual nitrogen removals from the site, respectively. Virtually all of the nitrogen leaving the site that was not removed in harvested crops or by volatilization was discharged in the ground water.

Applications of manure and fertilizer nitrogen to 47.5 acres of cropped fields decreased about 33 percent, from an average of 22,700 pounds per year (480 pounds per acre per year) before nutrient management to 15,175 pounds of nitrogen per year (320 pounds per acre per year) after the implementation of nutrient management practices. Nitrogen loads in ground‐water discharged from the site decreased about 30 percent, from an average of 292 pounds of nitrogen per million gallons of ground water before nutrient management to an average of 203 pounds of nitrogen per million gallons as a result of the decreased manure and commercial fertilizer applications. Reductions in manure and commercial fertilizer applications caused a reduction of approximately 11,000 pounds (3,760 pounds per year; 70 pounds per acre per year) in the load of nitrogen discharged in ground water from the 55‐acre site during the three‐year period 1987–1990.
QUALITY ASSURANCE TECHNIQUES FOR ELECTRONIC DATA ACQUISITION1
Authors: Whitfield Paul H. , Wade Norman L.
Published: June 2007

ABSTRACT: Electronic instruments are increasingly being used to gather water quality data. Quality assurance protocols are needed which provide adequate documentation of the procedures followed in calibration, collection, and validation of electronically acquired data. The level of precision of many data loggers exceeds the technology which is commonly used to make field measurements. Overcoming this problem involves using laboratory quality equipment in the field or enhanced quality control at the time of instrument servicing. Time control procedures for data loggers are needed to allow direct comparisons of data between instruments. Electronic instruments provide a mechanism to study transient events in great detail, but, without time controls, multiple loggers produce data which contain artifacts due to timing errors. Individual sensors deployed with data loggers are subject to different degrees of drift over time. Certain measurements can be measured with defined precision and accuracy for long periods of time, while other sensors are subject to loss of both precision and accuracy with increasing time of use. Adequate quality assurance requires the levels of precision and accuracy be documented, particularly those which vary with increasing time deployment.
TRINITY RIVER BASIN, TEXAS1
Authors: Ulery Randy L. , Van Metre Peter C. , Crossfield Allison S.
Published: June 2007

ABSTRACT: In 1991 the Trinity River Basin National Water‐Quality Assessment (NAWQA) was among the first 20 study units to begin investigations under full‐scale program implementation. The study‐unit investigations will include assessments of surface‐water and ground‐water quality. Initial efforts have focused on identifying water‐quality issues in the basin and on the environmental factors underlying those issues. The environmental setting consists of both physical and cultural factors. Physical characteristics described include climate, geology soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, and reservoir operations. Major water‐quality categories are identified and some of the implications of the environmental factors for water quality are presented.
OPEN CHANNEL INTERPOLATION OF CROSS SECTIONAL PROPERTIES1
Authors: Traver Robert G. , Miller Arthur C.
Published: June 2007

ABSTRACT: This paper confirms the use of interpolated data to refine water surface profiles. Sources of error within these computations are due to truncation error, inaccuracies in geometric data, and improper modeling. Confirmation includes the development of an equation that models the effect of data measurement error on the computed water surface profile. A review of interpolation procedures includes a proposed method based upon geometric properties.
SIMULATION AND MAPPING OF SOIL‐WATER CONDITIONS IN THE GREAT PLAINS1
Authors: Zelt Ronald B. , Dugan Jack T.
Published: June 2007

ABSTRACT: Soil‐water conditions provide valuable insight into the hydrologic system in an area. A soil‐water balance quantitatively summarizes soil‐water conditions and is based on climatic, soil, and vegetation characteristics that vary spatially and temporally. Soil‐water balances in the Great Plains of the central United States were simulated for 1951–1980. Results of the simulations were mean annual estimates of infiltration, runoff, actual evapotranspiration, potential recharge, and consumptive water and irrigation requirements at 152 climatic data stations. A method was developed using a geographic information system to integrate and map the simulation results on the basis of spatially variable climatic, soil, and vegetation characteristics. As an example, simulated mean annual potential recharge was mapped. Mean annual potential‐recharge rates ranged from less than 0.5 inch in much of the north‐central and southwestern Great Plains to more than 10 inches in parts of eastern Texas and southwestern Arkansas.
TIDE GATE INFLUENCES ON A TIDAL MARSH1
Authors: Pearlstine Leonard G. , Kitchens Wiley M. , Latham Pamela J. , Bartleson Richard D.
Published: June 2007

ABSTRACT: Construction of a tide gate at the mouth of the north channel of the Savannah River in Georgia has resulted in significant changes in salinities influencing marsh community changes. The tide gate is directly responsible for a 2 to 6 mile upstream displacement of salt water in the river. In the marsh, soil salinities ranged from 0.0 ppt at upstream sites to 12 ppt at downstream sites when the tide gate was in operation. Within two months of taking the tide gate out of operation, interstitial salinities at the downstream sites dropped to 4 ppt. Influences of the tide gate on marsh vegetation were modeled in a geographic information system. With the tide gate out of operation, the model predicts that freshwater marsh would increase in area by 340 percent.
APPLICATIONS OF A GIS FOR MODELING THE SENSITIVITY OF WATER RESOURCES TO ALTERATIONS IN CLIMATE IN THE GUNNISON RIVER BASIN, COLORADO1
Authors: Battaglin William A. , Hay Lauren E. , Parker Randolph S. , Leauesley George H.
Published: June 2007

ABSTRACT: The Gunnison River drains a mountainous basin in western Colorado, and is a large contributor of water to the Colorado River. As part of a study to assess water resource sensitivity to alterations in climate in the Gunnison River basin, climatic and hydrologic processes are being modeled. A geographic information system (GIS) is being used in this study as a link between data and modelers ‐ serving as a common data base for project personnel with differing specialties, providing a means to investigate the effects of scale on model results, and providing a framework for the transfer of parameter values among models. Specific applications presented include: (1) developing elevation grids for a precipitation model from digital elevation model (DEM) point‐elevation values, and visualizing the effects of grid resolution on model results; (2) using a GIS to facilitate the definition and parameterization of a distributed‐parameters, watershed model in multiple basins; and (3) nesting atmospheric and hydrologic models to produce possible scenarios of climate change.
A COMPARISON OF RUNOFF QUALITY EFFECTS OF ORGANIC AND INORGANIC FERTILIZERS APPLIED TO FESCUEGRASS PLOTS1
Authors: Edwards D. R. , Daniel T C.
Published: June 2007

ABSTRACT: Application of fertilizer can degrade quality of runoff, particularly during the first post‐application, runoff‐producing storm. This experiment assessed and compared runoff quality impacts of organic and inorganic fertilizer application for a single simulated storm occurring seven days following application. The organic fertilizers used were poultry (Gallus gallus domesticus) litter, poultry manure, and swine (Sus scrofa domesticus) manure. All fertilizers were applied at an application rate of 217.6 kg N/ha. Simulated rainfall was applied at 50 mm/h for an average duration of 0.8 h. Runoff samples were collected, composited, and analyzed for nitrate N (NO3‐N), ammonia N (NH3‐N), total Kjeldahl N (TKN), ortho‐P (PO4‐P), total P (TP), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliforms (FC), and fecal streptococci (FS). Application of the fertilizers did not alter the hydrologic characteristics of the receiving plots relative to the control plots. Concentrations of fertilizer constituents were almost always greater from treated than from control plots and were usually much greater. Flow‐weighted mean concentrations of NH3‐N, PO4‐P, and TP were highest for the inorganic fertilizer treatment (42.0, 26.6, and 27.9 mg/L, respectively). Runoff COD and TSS concentrations were greatest for the poultry litter treatment. Concentrations of FC and FS were greater for fertilized than for control plots with no differences among fertilized plots, but FC concentrations for all treatments were in excess of Arkansas' primary and secondary contact standards. Mass losses of fertilizer constituents were low (≤ 3 kg/ha) and were small proportions (≤ 3 percent) of amounts applied.
EVALUATION OF THE MAXEY‐EAKIN METHOD FOR ESTIMATING RECHARGE TO GROUND‐WATER BASINS IN NEVADA1
Authors: Avon Lizanne , Durbin Timothy J.
Published: June 2007

AESTRACT An evaluation of the Maxey‐Eakin method for calculating recharge to ground‐water basins in Nevada was performed. The evaluation consisted of comparing Maxey‐Eakin estimates with independent estimates of recharge, and analyzing the nature of the differences between the groups of estimates. In the comparison with the Maxey‐Eakin estimates, two different groups of independent estimates were used: (1) 40 recharge estimates that were identified from water budgets contained in reports by the Nevada Department of Conservation and Natural Resources and (2) 27 recharge estimates that were identified from previous studies that used models. The results of the comparisons indicate generally good agreement between the Maxey‐Eakin estimates and both groups of independent estimates. To quantify this agreement, an analysis was conducted to estimate the uncertainty in the Maxey‐Eakin method. The analysis produced an upper bound on the standard deviation of the Maxey‐Eakin estimate for a given basin. For the group of 40 water‐budget estimates, the upper bound on the standard deviation for an individual basin is 4,800 acre‐ft/yr, and the corresponding coefficient of variation of the Maxey‐Eakin estimate is no greater than 44 percent. For the group of 27 model estimates, the upper bound on the standard deviation is 4,100 acre‐ft/yr, and the corresponding coefficient of variation is no greater than 24 percent.
HYDROGEOLOGY AND PATHS OF FLOW IN THE CARBONATE BEDROCK AQUIFER, NORTHWESTERN INDIANA1
Authors: Arihood Leslie D.
Published: June 2007

ABSTRACT: The U.S. Geological Survey (USGS) is assessing the ground‐water resources of the carbonate bedrock aquifers in Indiana and Ohio as part of their Regional Aquifer Systems Analysis program. Part of this assessment includes the determination of unknown aspects of the hydraulic characteristics, boundaries, and flow paths of the carbonate aquifer. To accomplish this, the USGS drilled three wells through the carbonate aquifer near the Kankakee River in northwestern Indiana. Geophysical logs were used to help determine depths and thicknesses for testing and to help describe geology at the three wells. Packer tests were used to determine direction of ground‐water flow and to provide data for an analysis of the distribution of transmissivity in the carbonate aquifer.

Transmissivity of the carbonates is associated with two physical characteristics of the rocks: fractures and interconnected porosity. Almost all of the transmissivity is derived from horizontal fracturing; however, only a few of the fractures present in the carbonate are transmissive. Some transmissivity is associated with a zone of fossiliferous, vuggy dolomite, which yields water from the rock matrix. Most of the transmissivity is associated with large fractures and solution crevices in the upper 30 feet of the bedrock; less transmissivity is associated with the deeper vuggy reef material, even where extensively fractured. Transmissivity of individual fractures and fossiliferous zones ranges from 300 to 27,000 feet squared per day. The aquifer bottom is defined by a lack of transmissive fractures and an increased shale content near the contact of the Silurian and Ordovician sections.

Water‐level data from the three wells indicate that flow is horizontal at well site 1 north of the Kankakee River, upward at well site 2 near the river, and downward at well site 3 south of the river. Most of the flow occurs in the upper part of the carbonate bedrock where fracturing and solution‐enlarged crevices are most developed. Water levels indicate the the Kankakee River is a hydrologic boundary for the regional carbonate bedrock aquifer.
POTENTIAL EFFECTS OF DEVELOPMENT ON FLOW CHARACTERISTICS OF TWO NEW JERSEY STREAMS1
Authors: Barringer Thomas H. , Reiser Robert G. , Price Curtis V
Published: June 2007

ABSTRACT: Parts of the Raritan River basin in central New Jersey have undergone increasing development over the last several decades. The increasing population relies on the region's ground water and surface water sources for its residential, commercial, and industrial water supply. Urbanization, regionalized wastewater‐treatment facilities, stream channel alterations, and interbasin transfers of water can all affect water availability. This pilot study was conducted to determine whether significant trends exist in the base‐flow and overland‐runoff characteristics of streams in two subbasins with different percentages of urban/built‐up land (Anderson et at., 1976). Changes in flow characteristics that could indicate future reductions in safe water yield of the Raritan River basin were examined. Flow and flow variability of the steams draining these two subbasins have increased over time. Many of the flow measures studied experienced pronounced trend shifts about 1960. The cause of these changes cannot be readily determined from the data, nor is it clear whether the increased flow variability lies outside the natural range of flow variability of the streams draining the subbasins.
EFFECTS OF SOIL TYPE, PLOT CONDITION, AND SLOPE ON RUNOFF AND INTERRILL EROSION OF TWO SOILS IN THE LAKE TAHOE BASIN1
Authors: Naslas G. D. , Miller W. W. , Gifford G. F. , Fernandez G. C. J.
Published: June 2007

ABSTRACT: Few studies have addressed sediment discharge due to interrill erosion from natural and minimally disturbed alpine and subalpine forested watersheds. Infiltration, runoff, and surface erosion of two Tahoe Basin soils under several conditions were investigated using rainfall simulation. A significant three‐way interaction among soil type, plot condition, and slope was identified. Although high erodibiity was commonly associated with disturbance and/or high slope, this was not always the case. Soil type, plot condition, slope, and duration of the event were all found to be important factors in determining the amount of erosion. Decreased water clarity in Lake Tahoe has been partly attributed to increased algal growth associated with surface runoff and erosion from adjacent watersheds. Interpretive evaluation for resource management planning should be event based and carefully delineated on a sitespecific basis.
SEDIMENT, NITRATE, AND AMMONIUM IN SURFACE RUNOFF FROM TWO TAHOE BASIN SOIL TYPES1
Authors: Naslas G. D. , Miller W W. , Blank R. R. , Gifford G. F.
Published: June 2007

ABSTRACT:Few studies have addressed the natural pollution potential of pristine subalpine forested watersheds on a site‐specific basis. Consequently, specific source and amounts of nutrient discharge to tributaries of the Tahoe Basin are difficult to identify. The sediment content and nitrate and ammonium levels in surface runoff from two soil types (Meeks and Umpa), four plot conditions (wooded natural and disturbed, open natural and disturbed), and three slopes (gentle, moderate, and steep) were studied using rainfall simulation that applied a 9 cm h1, 1‐h event. A significant (P ≤ 0.005) two‐way interaction between soil type and plot condition affected runoff nitrate concentration. Runoff from natural or disturbed open plots contained significantly (P = 0.05) greater nitrate than wooded plots. Peak concentrations of nitrate commonly occurred during early runoff, suggesting that peak nitrate discharge to Lake Tahoe tributaries can be expected during early runoff from snowmelt and summer precipitation events. The highest nitrate runoff concentration and 1‐h cumulative loading from the 0.46 m2plots were 6.7 mg L‐1(Umpa, open natural, 15–30 percent slope), and 0.7 mg (Umpa, open natural, ≥ 30 percent slope), respectively. Ammonium in surface runoff was generally below detection limits (≤ 0.05 μgL−1). No statistical relationship between runoff nitrate and sediment discharge was detected.
MODEL ACCURACY IN SNOWMELT‐RUNOFF FORECASTS EXTENDING FROM 1 TO 20 DAYS1
Authors: Rango A. , Martinec J.
Published: June 2007

ABSTRACT: This paper examines the performance of snowmelt‐runoff models in conditions approximating real‐time forecast situations. These tests are one part of an intercomparison of models recently conducted by the World Meteorological Organization (WMO). Daily runoff from the Canadian snowmelt basin Illecille. waet (1155 km2, 509–3150 m a.s.l.) was forecast for 1 to 20 days ahead. The performance of models was better than in a previous WMO project, which dealt with runoff simulations from historical data, for the following reasons: (1) conditions for models were more favorable than a real‐time forecast situation because measured input data and not meteorological forecast inputs were distributed to the modelers; (2) the selected test basin was relatively easy to handle and familiar from the previous WMO project; and (3) all kinds of updating were allowed so that some models even improved their accuracy towards longer forecast times. Based on this experience, a more realistic follow‐up project can be imagined which would include temperature forecasts and quantitative precipitation forecasts instead of measured data.
MEAN AREAL PRECIPITATION FOR DAILY HYDROLOGIC MODELING IN MOUNTAINOUS REGIONS1
Authors: Garen David C. , Johnson Gregory L. , Hanson Clayton L.
Published: June 2007

ABSTRACT: A procedure using detrended kriging has been developed to calculate daily values of mean areal precipitation (MAP) for input to hydrologic models. The important features of this procedure that overcome weaknesses in existing MAP procedures are: (1) specific precipitation‐elevation relationships are determined for each time period as opposed to using relationships based on climatological averages, (2) spatial variability is incorporated by estimating precipitation for each grid cell over a watershed, (3) the spatial correlation structure of precipitation is explicitly modeled, and (4) station weights for precipitation estimates are determined objectively and optimally. Detailed cross‐validation testing of the procedure was done for the Reynolds Creek research watershed in southwestern Idaho. The procedure is suitable for use in operational streamflow forecasting.