bluuebunny/crossref_metadata_2025 huggingface dataset:
A CRITIQUE OF WATERSHED MANAGEMENT EFFORTS IN THE LOWER MISSISSIPPI ALLUVIAL PLAIN1
Authors: Ballweber Jeffery A.
Published: June 2007

ABSTRACT: Integrated watershed management in the Lower Mississippi Alluvial Plain (Delta) requires blending federal, state, and local authority. The federal government has preeminent authority over interstate navigable waters. Conversely, state and local governments have authority vital for comprehensive watershed management. In the Delta, integrating three broad legal and administrative regimes: (1) flood control, (2) agricultural watershed management, and (3) natural resources and environmental management, is vital for comprehensive intrastate watershed, and interstate river basin management. Federal Mississippi River flood control projects incorporated previous state and local efforts. Similarly, federal agricultural programs in the River's tributary headwaters adopted watershed management and were integrated into flood control efforts. These legal and administrative regimes implement national policy largely in cooperation with and through technical and financial assistance to local agencies such as levee commissions and soil and water conservation districts. This administrative infrastructure could address new national concerns such as nonpoint source pollution which require a watershed scale management approach. However, the natural resources and environmental management regime lacks a local administrative infrastructure. Many governmental and non governmental coordinating organizations have recently formed to address this shortcoming in the Delta. With federal and state leadership and support, these organizations could provide mechanisms to better integrate natural resources and environmental issues into the Delta's existing local administrative infrastructure.
STAKEHOLDER INVOLVEMENT AND SOCIAL CAPITAL: KEYS TO WATERSHED MANAGEMENT SUCCESS IN ALABAMA1
Authors: Mullen Michael William , Allison Bruce E.
Published: June 2007

ABSTRACT: Forces driving the initiation of watershed management activities in Alabama have ranged from top‐down, agency‐led initiatives to bottom‐up, citizen‐led initiatives. A number of watershed projects in Alabama were examined including three NPS projects funded by U.S. EPA grants and a more comprehensive locally‐initiated watershed management authority. Watershed projects were categorized into four different models. Factors which produced significant differences in the development and utilization of social capital and local capacities for watershed management were investigated. The success of watershed management initiatives was examined qualitatively and appears to correlate with a number of social factors. These factors include the extent of stakeholder involvement, the availability of social capital in the watershed, and the presence of a real or perceived water resource concern or problem. Both short term project success and the longer term prognosis for continued watershed management activities seems to depend most upon the amount of social capital in the watershed. Two major changes in resource management programs and organizations could lead to increased focus on and support for local watershed management initiatives. These are reorganization of resource management agencies around watershed units, and assignment of at least one staff person in each watershed unit to watershed management.
LANDCARE AND COMMUNITY‐LED WATERSHED MANAGEMENT IN VICTORIA, AUSTRALIA1
Authors: Ewing Sarah
Published: June 2007

ABSTRACT: Australia's ‘Landcare’ program is a community‐based participatory program established by government to tackle the problem of land degradation. Landcare involves thousands of Australians working together in locally based groups, tackling problems of common concern. Government and community are now looking to ‘scale up’ the Landcare idea to a regional level. State and territory governments have moved to create regional (often watershed‐based) frameworks for land management planning and resource conservation, in accordance with the concept of integrated watershed management. Growing out of the success of community involvement in Landcare, many of these approaches involve the community. However scaling up of the Landcare idea introduces problems of both time and space. There have been a number of problems experienced in the implementation of Landcare and integrated watershed management. These problems include the equitable delineation of membership on decision‐making bodies; the raising of sufficient funds for program implementation; and the coordination of a diversity of governmental layers, planning processes and management programs. This paper reviews how the State of Victoria has responded to these challenges and suggests what challenges remain.
A PROPOSED APPROACH TO COORDINATION OF WATER RESOURCE DEVELOPMENT AND ENVIRONMENTAL REGULATIONS1
Authors: Whipple William , Duflois Donald , Grigg Neil , Herricks Edwin , Holme Howard , Jones Jonathan , Keyes Conrad , Ports Mike , Rogers Jerry , Strecker Eric , Tucker Scott , Urbonas Ben , Viessman Bud , Vonnahme Don
Published: June 2007

ABSTRACT: The planning and developing of water resources to meet the country's needs for water supply, flood control, hydroelectric power, irrigation, and navigation now needs to take more account of environmental needs and regulations. Water resource development is often beneficial to the environment, but may also be harmful, as in cases involving salmon and various other endangered species. As a national objective, the environment must be preserved and in some cases restored; but how can this be done consistent with other national objectives, relating to life and welfare of human beings? This problem has aroused the concern of many engineers and water scientists. As a result, a national conference on this subject was held in Chicago in June 1998, as an integral part of ASCE's Annual Conference on Water Resources Planning and Management and the Annual Conference on Environmental Engineering. At the conclusion of that conference, a post‐conference meeting was held by a group of prominent water resource practitioners. It was concluded at this meeting that action should be taken by our government to establish a new form of interagency approach, involving the states, as a means of coordination in cases of national importance.
SELECTION AND SUSTAINABILITY OF LAND AND WATER RESOURCE MANAGEMENT SYSTEMS1
Authors: Prato Tony , Hajkowicz Stefan
Published: June 2007

ABSTRACT: Most spatial decision support systems for natural resource planning and management are limited by their scenario‐based (non‐behavioral), deterministic (non‐stochastic) structure. A spatial decision support system is developed that uses a multiple attribute decision‐making model to explain how a property manager selects a land and water resource management system (LWRMS) based on its multiple, stochastic economic and environmental attributes. The decision support system assesses sustainable resource management at the property and watershed scales and identifies the most cost‐effective policy for enhancing sustainable resource management. Economic attributes are determined with an economic model and environmental attributes are simulated with an environmental model. Input parameters for both models are generated with a geographic information system. The decision support system is used to rank five LWRMS for a sample of 20 farmers in Missouri's Goodwater Creek watershed and for two hypothetical watershed alliance groups. Results indicate that the average farmer and the two alliance groups would rank the five LWRMS in the same manner. From the viewpoint of the watershed alliance, the most preferred LWRMS for the average farmer in the watershed is sustainable.
EVALUATION OF RUNOFF, EROSION, AND PHOSPHORUS MODELING SYSTEM—SIMPLE1
Authors: Kornecki Ted S. , Sabbagh George J. , Storm Daniel E.
Published: June 2007

ABSTRACT: The purpose of this study was to evaluate the performance of Spatially Integrated Models for Phosphorus Loading and Erosion (SIMPLE) in predicting runoff volume, sediment loss, and phosphorus loading from two watersheds. The modeling system was applied to the 334 ha QOD subwatershed, part of the Owl Run watershed, located in Fauquier County, Virginia, and to the 2240 ha watershed, Battle Branch, located in Delaware County, Oklahoma. Simulation runs were conducted at cell and field scales, and simulation results were compared with observed data. Runoff volume and dissolved phosphorus loading were measured at the Battle Branch watershed. Runoff volume, sediment yield, and total phosphorus loading were measured at the QOD site. SIMPLE tended to underestimate runoff volumes during the dormant period, from November to March. The comparison between observed and predicted dissolved phosphorus showed better correlation than for observed and predicted total phosphorus loading. Cell level simulations provided similar estimates of runoff volume and phosphorus loading when compared to field level simulations for both watersheds. However, observed sediment yields better compared with the values predicted from the cell level simulation when compared to field level simulation. Finally, results of model evaluation indicated that SIMPLE's predictive ability is acceptable for screening applications but not for site‐specific quantitative predictions.
ESTIMATION OF LONG‐TERM DISCHARGE STATISTICS BY REGIONAL ADJUSTMENT1
Authors: Bakke Paul D. , Thomas Robert , Parrett Charles
Published: June 2007

ABSTRACT: A regional adjustment relationship was developed to estimate long‐term (30‐year) monthly median discharges from short term (three‐year) records. This method differs from traditional approaches in that it is based on site‐specific discharge data but does not require correlation of these data with discharges from a single hydrologically similar long‐term gage. The method is shown to be statistically robust, and applicable to statistics other than the median.
EXTERNALITIES, WATER PRICES, AND WATER TRANSFERS1
Authors: Jordan Jeffrey L.
Published: June 2007

Discussing, estimating or analyzing the value of water is a difficult task. In addressing the value of water as reflected in its price — either as charged by a water utility, as the price of a water transfer, or a water sale in some market — this paper will examine three propositions regarding water pricing. The paper will consider the marginal scarcity rent of water, estimates of externalities, the full cost pricing of water and the consequences of these considerations on water prices, transfers and the efficiency of water use.
BENEFITS FROM MANAGING FARM PRODUCED NUTRIENTS1
Authors: Ogg Clayton
Published: June 2007

Manures and fertilizers are applied to agricultural lands in excess of recommended amounts, resulting in widespread pollution of surface and ground water and contributing a substantial source of greenhouse gases associated with global warming. By developing policies that exploit the value of farm produced nutrients, input costs can be minimized. Better accounting for or crediting of farm produced nutrients is leading to economically beneficial conservation of fertilizer. In addition, hog producers who own enough land may benefit from properly managing manure nutrients. Poultry litter is valuable as fertilizer and can be marketed by independent dealers to farmers in nutrient deficit areas, with very modest assistance from the government. Dairy producers may modify their past income support programs to finance central compost facilities. Although nutrient problems were neglected in the past, recent Federal initiatives and joint initiatives with states exploit many of these and other opportunities to avoid excessive application of nutrients to the land.
ESTIMATING ATRAZINE LEACHING IN THE MIDWEST1
Authors: Burkart Michael R. , Gassman Philip W. , Moorman Thomas B. , Singh Piyash
Published: June 2007

Data from seven Management Systems Evaluation Areas (MSEA) were used to test the sensitivity of a leaching model, Pesticide Root Zone Model‐2, to a variety of hydrologic settings in the Midwest. Atrazine leaching was simulated because it was prevalent in the MSEA studies and is frequently detected in the region's groundwater. Short‐term simulations used site specific soil and chemical parameters. Generalized simulations used data avail. able from regional soil databases and standardized variables. Accurate short‐term simulations were precluded by lack of antecedent atrazine concentrations in the soil profile and water, suggesting that simulations using data for less than five years underestimate atrazine leaching. The seven sites were ranked in order of atrazine detection frequency (concentration > 0.2 μg L‐1) in soil water at 2 m depth in simulations. The rank order of the sites based on long‐term simulations were similar to the ranks of sites based on atrazine detection frequency from groundwater monitoring. Simulations with Map Unit Use File (MUUF) soils data were more highly correlated with ranks of observed atrazine detection frequencies than were short‐term simulations using site‐specific soil data. Simulations using the MIJUIF data for soil parameters were sufficiently similarity to observed atrazine detection to allow the credible use of regional soils data for simulating leaching with PRZM‐2 in a variety of Midwest soil and hydrologic conditions. This is encouraging for regional modeling efforts because soil parameters are among the most critical for operating PRZM‐2 and many other leaching models.
COMPARISON OF TRACE ELEMENT CONCENTRATIONS IN TISSUE OF COMMON CARP AND IMPLICATIONS FOR MONITORING1
Authors: Goldstein Robert M. , DeWeese L. Rod
Published: June 2007

Common carp (Cyprinus carpio) collected from four sites in the Red River of the North in 1994 were analyzed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), selenium (So), and zinc (Zn). Concentrations differed among liver, muscle, and whole body. Generally, trace element concentrations were the greatest in livers while concentrations in whole bodies were greater than those in muscle for Cd, Cu, Ni, Pb, and Zn, and concentrations in muscle were similar to whole body for As and Se. Concentrations of Cr were lower in liver than either muscle or whole body. Correlations between liver and whole body concentrations were stronger than those between liver and muscle concentrations, but the strongest correlations were between muscle and whole body concentrations. Examination of tissue concentrations by collection sites suggested that, for a general survey, the whole body may be the most effective matrix to analyze.
EROSION ON LOGGING ROADS IN REDWOOD CREEK, NORTHWESTERN CALIFORNIA1
Authors: Rice Raymond M.
Published: June 2007

Road‐related erosion was estimated by measuring 100 randomly located plots on a 180 km road network in the middle reach of R'dwood Creek in northwestern California. The estimated erosion ratn of 177 m3km‐1was contrasted with two earlier studies in nearby parts of the same watershed. A sizable proportion of the great reduction in erosion from that reported in the earlier studies is attributed to changes in forest practice rules. Those changes have resulted in better placement and sizing of culverts and, especially, to less reliance on culverts to handle runoff from logging roads.
USE OF A VIEWER BOX IN SECCIII DISK MEASUREMENTS1
Authors: Smith David G. , Hoover Creighton M.
Published: June 2007

We used a closed‐ended viewer box in the measurement of Secchi depth and compared the results with simultaneous naked‐eye measurements. We have shown that use of such a viewer box increases Secchi depth measurement by removing the interfering effects of water surface glare and glitter. A viewer box also increases between‐observer precision. Measurements made both with and without the viewer box are slightly greater on the shady side of the boat than on the sunny side; the latter is the preferred side if Secchi data are to be related to other optical properties. As expected, the difference between viewer box and naked eye measurements increases with increasing wave height but not with increasing illuminance. Because of the lack of uniformity in the way Secchi depth is estimated, and the inherent optical problems with current Secchi depth procedures, an appeal is made for production of a standardized protocol for Secchi observations, including the use of a closed‐ended viewer box on the sunny side of the boat.
GROUNDWATER GEOCHEMISTRY IN THE SEMINOLE WELL FIELD, CEDAR RAPIDS, IOWA1
Authors: Boyd Robert A.
Published: June 2007

The City of Cedar Rapids obtains its municipal water supply from four well fields in an alluvial aquifer along the Cedar River in east‐central Iowa. Since 1992, the City and the U.S. Geological Survey have cooperatively studied the groundwater‐flow system and water chemistry near the well fields. The geochemistry in the alluvial aquifer near the Seminole Well Field was assessed to identify potentially reactive minerals and possible chemical reactions that produce observed changes in water chemistry. Calcite, dolomite, ferrihydrite, quartz, rhodochrosite, and siderite were identified as potentially reactive minerals by calculating saturation indexes. Aluminosiicate minerals including albite, Ca‐montmorillonite, gibbsite, illite, K‐feldspar, and kaolinite were identified as potentially reactive minerals using hypothetical saturation indexes calculated with an assumed dissolved aluminum concentration of 1 microgram per liter. Balanced chemical equations derived from inverse‐modeling techniques were used to assess chemical reactions as precipitation percolates to the water table. Calcite dissolution was predominate, but aluminosilicate weathering, cation exchange, and redox reactions also likely occurred. Microbial‐catalyzed redox reactions altered the chemical composition of water infiltrating from the Cedar River into the alluvial aquifer by consuming dissolved oxygen, reducing nitrate, and increasing dissolved iron and manganese concentrations. Nitrate reduction only occurred in relatively shallow (3 to 7 meters below land surface) groundwater near the Cedar River and did not occur in water infiltrating to deeper zones of the alluvial aquifer.
IMPACTS OF CLIMATE CHANGE ON AQUATIC ECOSYSTEM FUNCTIONING AND HEALTH1
Authors: Meyer Judy L. , Sale Michael J. , Mulholland Patrick J. , Poff N. LeRoy
Published: June 2007

ABSTRACT: We review published analyses of the effects of climate change on goods and services provided by freshwater ecosystems in the United States. Climate‐induced changes must be assessed in the context of massive anthropogenic changes in water quantity and quality resulting from altered patterns of land use, water withdrawal, and species invasions; these may dwarf or exacerbate climate‐induced changes. Water to meet instream needs is competing with other uses of water, and that competition is likely to be increased by climate change. We review recent predictions of the impacts of climate change on aquatic ecosystems in eight regions of North America. Impacts include warmer temperatures that alter lake mixing regimes and availability of fish habitat; changed magnitude and seasonality of runoff regimes that alter nutrient loading and limit habitat availability at low flow; and loss of prairie pothole wetlands that reduces waterfowl populations. Many of the predicted changes in aquatic ecosystems are a consequence of climatic effects on terrestrial ecosystems; shifts in riparian vegetation and hydrology are particularly critical. We review models that could be used to explore potential effects of climate change on freshwater ecosystems; these include models of instream flow, bioenergetics models, nutrient spiraling models, and models relating riverine food webs to hydrologic regime. We discuss potential ecological risks, benefits, and costs of climate change and identify information needs and model improvements that are required to improve our ability to predict and identify climate change impacts and to evaluate management options.
THE IMPACTS OF CLIMATIC CHANGES FOR WATER RESOURCES OF THE COLORADO AND SACRAMENTO‐SAN JOAQUIN RIVER BASINS1
Authors: Gleick Peter H. , Chalecki Elizabeth L.
Published: June 2007

ABSTRACT: A wide variety of regional assessments of the water‐related impacts of climatic change have been done over the past two decades, using different methods, approaches, climate models, and assumptions. As part of the Water Sector research for the National Assessment of the Implications of Climatic Variability and Change for the United States, several major summaries have been prepared, looking at the differences and similarities in results among regional research projects. Two such summaries are presented here, for the Colorado River Basin and the Sacramento River Basin. Both of these watersheds are vitally important to the social, economic, and ecological character of their regions; both are large snowmelt‐driven basins; both have extensive and complex water management systems in place; and both have had numerous, independent studies done on them. This review analyzes the models, methods, climate assumptions, and conclusions from these studies, and places them in the context of the new climate scenarios developed for the National Assessment. Some significant and consistent impacts have been identified for these basins, across a wide range of potential climate changes. Among the most important is the shift in the timing of runoff that results from changes in snowfall and snowmelt dynamics. This shift has been seen in every regional result across these two basins despite differences in models and climate change assumptions. The implications of these impacts for water management, planning, and policy are discussed.
VARIABILITY CHARACTERISTICS OF MONTHLY PRECIPITATION IN CENTRAL OKLAHOMA1
Authors: Rossel Frédéric , Garbrecht Jurgen
Published: June 2007

ABSTRACT: To fully take advantage of regional climate forecast information for agricultural applications, the relationship between divisional and station scale precipitation characteristics must be quantified. The spatial variability of monthly precipitation is assumed to consist of two components: a systematic and a random component. The systematic component is defined by differences in long‐term mean precipitation between stations within a climate division, and the random component by differences between station and divisional standardized values. For the Central Climate Division of Oklahoma, the systematic component has a positive precipitation gradient from west to east with a slope ranging between 3 to 16 mm of precipitation per 100 km depending on the month of the year. On the other hand, the random component ranges between 27 to 48 percent of the mean temporal variation of the monthly precipitation. This significant random spatial variability leads to large localized departures from divisional values, and clearly demonstrates the critical influence of the random component in the utilization of divisional climate forecasts for local agricultural applications. The results of this study also provide an uncertainty range for local monthly precipitation projections that are derived from divisional climate information.
ASSESSMENT OF IMPACTS OF CLIMATE CHANGE ON WATER QUALITY IN THE SOUTHEASTERN UNITED STATES1
Authors: Cruise James F. , Limaye Ashutosh S. , Al‐Abed Nassim
Published: June 2007

ABSTRACT: An assessment of current and future water quality conditions in the southeastern United States has been conducted using the EPA BASINS GIS/database system. The analysis has been conducted for dissolved oxygen, total nitrate nitrogen and pH. Future streamflow conditions have been predicted for the region based on the United Kingdom Hadley Center climate model. Thus far, the analyses have been conducted at a fairly coarse spatial scale due to time and resource limitations. Two hydrologic modeling techniques have been employed in future streamflow prediction: a regional stochastic approach and the application of a physically based soil moisture model. The regional model has been applied to the entire area while the physically based model is being used at selected locations to enhance and support the stochastic model. The results of the study reveal that few basins in the southeast exhibit dissolved oxygen problems, but that several watersheds exhibit high nitrogen levels. These basins are located in regions of intense agricultural activity or in proximity to the gulf coast. In many of these areas, streamflow is projected to decline over the next 30–50 years, thus exacerbating these water quality problems.
NEW METHODS OF MODELING WATER AVAILABILITY FOR AGRICULTURE UNDER CLIMATE CHANGE: THE U.S. CORNBELT1
Authors: Strzepek Kenneth M. , Major David C. , Rosenzweig Cynthia , Iglesias Ana , Yates David N. , Holt Alyssa , Hillel Daniel
Published: June 2007

ABSTRACT: This paper reports on new methods of linking climate change scenarios with hydrologic, agricultural an water planning models to study future water availability for agriculture, an essential element of sustainability. The study is based on the integration of models of water supply and demand, and of crop growth and irrigation management. Consistent modeling assumptions, available databases, and scenario simulations are used to capture a range of possible future conditions. The linked models include WATBAL for water supply; CERES, SOYGRO, and CROPWAT for crop and irrigation modeling; and WEAP for water demand forecasting, planning and evaluation. These models are applied to the U.S. Cornbelt using forecasts of climate change, agricultural production, population and GDP growth.

Results suggest that, at least in the near term, the relative abundance of water for agriculture can be maintained under climate change conditions. However, increased water demands from urban growth, increases in reservoir evaporation and increases in crop consumptive use must be accommodated by timely improvements in crop, irrigation and drainage technology, water management, and institutions. These improvements are likely to require substantial resources and expertise. In the highly irrigated basins of the region, irrigation demand greatly exceeds industrial and municipal demands. When improvements in irrigation efficiency are tested, these basins respond by reducing demand and lessening environmental stress with an improvement in system reliability, effects particularly evident under a high technology scenario. Rain‐fed lands in the Cornbelt are not forced to invest in irrigation, but there is some concern about increased water‐logging during the spring and consequent required increased investment in agricultural drainage. One major water region in the Cornbelt also provides a useful caveat: change will not necessarily be continuous and monotonic. Under one GCM scenario for the 2010s, the region shows a significant decrease in system reliability, while the scenario for the 2020s shows an increase.
INVERSE SOLUTION OF HYDRAULIC DIFFUSIVITY DETERMINED BY WATER LEVEL FLUCTUATION1
Authors: Shih David Ching‐Fang
Published: June 2007

ABSTRACT: This study uses the spectral analysis to inversely solve for hydraulic diffusivity of a one‐dimensional aquifer with boundaries subject to non‐steady state water level fluctuation. Given water level spectra obtained from observation wells and tidal gauge stations, hydraulic diffusivity of a confined aquifer in a Quaternary alluvial plain is found to be about 1.8×106m2/hr which is one order of magnitude higher than the value obtained from a local pump test performed in the same area.
SEMIPERMEABLE MEMBRANE DEVICES USED TO ESTIMATE BIOCONCENTRATION OF POLYCHLORINATED BIPHENYLS1
Authors: Chambers Douglas B.
Published: June 2007

ABSTRACT: Aquatic organisms passively accumulate hydrophobic organic compounds, such as polychlorinated biphenyls, even when ambient water concentrations of the contaminant are below analytical detection limits. However, contaminant concentrations in tissue samples are subject to an inherently high level of variability due to differences in species, life stage, and gender bioconcentration potentials. Semipermeable membrane devices (SPMDs) were used to sample Aroclor 1254, a mixture of readily bioconcentrated polychlorinated biphenyls (PCBs), in a contaminated wetland near Flat Top, WV. The devices consisted of triolein, a lipid found in fish, enclosed in a polyethylene membrane. SPMDs were deployed in the water column and in direct contact with wetland sediments along a previously identified concentration gradient of PCBs. The devices were retrieved after a 25‐day exposure period. Analytes were recovered by dialyzing the devices in nanograde hexane. Hexane dialysates were condensed and analyzed by gas chromatography. All deployed devices sequestered quantifiable amounts of Aroclor 1254. Water‐column SPMDs accumulated PCBs far in excess of ambient water concentrations. The devices contacting sediments accumulated PCBs at all sites, though accumulated concentrations did not exceed concentrations in sediment. Patterns of PCB concentration in the devices corresponded to the identified gradient at the site. Results from the water‐column SPMDs were used to estimate the concentration of the dissolved, bioavailable fraction of PCBs present in the water column. These concentrations ranged from 0.01 to 0.09 μg/L of bioavailable Aroclor 1254.
LABORATORY TESTS OF EROSION DEPENDENCE ON PROPERTIES OF SOILS AND RAINFALL1
Authors: Liu Hu , Cleveland Theodore G. , Han Wang Keh
Published: June 2007

ABSTRACT: One hundred and sixty‐two rainfall‐induced soil erosion tests were conducted to assist in predicting soil loss and subsequent increase in total suspended solids leaving a highway construction site during a rainfall event. A rainfall simulator and a water flume were constructed for the tests. Soil shear strength, compressive strength, rainfall intensity, and soil bed slope were treated as variables during the experiments. The soil with a higher shear strength resisted soil erosion better than lower strength soils. Soil loss was nearly independent of shear strength at low rainfall intensity but at high intensities, the shear strength was more important in resisting soil loss. Lower soil loss can be expected for cohesive soils if the compressive strength is high.
LANDSLIDE INITIATION, RUNOUT, AND DEPOSITION WITHIN CLEARCUTS AND OLD‐GROWTH FORESTS OF ALASKA1
Authors: Johnson A. C. , Swanston D. N. , McGee K. E.
Published: June 2007

ABSTRACT: More than 300 landslides and debris flows were triggered by an October 1993 storm on Prince of Wales Island, southeast Alaska. Initiation, runout, and deposition patterns of landslides that occurred within clearcuts, second‐growth, and old‐growth forests were examined. Blowdown and snags, associated with cedar decline and “normal” rates of mortality, were found adjacent to at least 75 percent of all failures regardless of land use. Nearly 50 percent of the landslides within clearcuts occurred within one year following timber harvest; more than 70 percent of these sites had hydrophytic vegetation directly above failures. In following the runout paths of failures, significantly more erosion per unit area occurred within clearcuts than in old‐growth forests on slopes with gradients from 9 to 28* (16 to 54 percent). Runout length, controlled by hillslope position within deglaciated valleys, was typically longer in old‐growth forests than in second growth and clearcuts (median values were 334, 201, and 153 m, respectively). Most landslides and debris flows deposited in first‐and second‐order channels before reaching the main stem channels used by anadromous fish. Slide deposits in old‐growth forests were composed of a higher proportion of woody debris than deposits derived from slides in second growth or clearcuts.
THE TWO‐DIMENSIONAL UPLAND EROSION MODEL CASC2D‐SED1
Authors: Johnson Billy E. , Julien Pierre Y , Molnar Darcy K , Watson Chester C.
Published: June 2007

ABSTRACT: The two‐dimensional soil erosion model CASC2D‐SED simulates the dynamics of upland erosion during single rainstorms. The model is based on the raster‐based surface runoff calculations from CASC2D. Rainfall precipitation is distributed in time and space. Infiltration is calculated from the Green‐Ampt equations. Surface runoff is calculated from the diffusive wave approximation to the Saint‐Venant equations in two‐dimensions. Watershed data bases in raster Geographical Information System (GIS) provide information on the soil type, size fractions, soil erodibility, cropping management, and conservation practice factors for soil erosion calculations. Upland sediment transport is calculated for the size fractions (sand, silt, and clay), and the model displays the sediment flux, the amount of suspended sediment, and the net erosion and deposition using color graphics. The model has been tested on Goodwin Creek, Mississippi. The peak discharge and time to peak are within ± 20 percent and sediment transport rates within −50 percent to 200 percent.
DO WETLANDS BEHAVE LIKE SHALLOW LAKES IN TERMS OF PHOSPHORUS DYNAMICS?1
Authors: Moustafa M. Z.
Published: June 2007

ABSTRACT: The applicability of empirical relationships governing phosphorus (P) retention and nutrient assimilation in lakes and reservoirs was extended to include free surface water wetland treatment systems. Mixed reactor models have been used in lakes to predict steady state P concentration, characterize trophic state, compare P‐dynamics, and predict permissible P‐loading rates. Applying lake models to free surface water wetlands treatment systems, it was found that: sedimentation rates, loading rates, and settling velocity in these wetlands, and their typology are comparable to their lake counterparts. The analyses also suggest that phosphorus removal efficiency in a free surface water wetland treatment system is independent of trophic status, and similar to lakes, these wetlands can be classified according to their trophic state. Oligo‐and eutrophic wetland treatment systems can be defined by low and high TP inflow concentrations, respectively. In this study, olig‐otrophic status is defined as systems receiving inflow P‐loading less than 0.10 g m‐2 year‐1, and their P inputs are mainly derived from agricultural and stormwater runoff. Eutrophic treatment systems, on the other hand, are defined as those receiving inflow P‐loading higher than 0.20 g m2 year‐1, and their inputs are mainly derived from industrial and municipal wastewater. The comparability found between lakes and free surface water wetlands treatment systems raises the question: should we consider these wetlands “shallow lakes?”
SOLUBLE SUGAR COMPOSITION OF POND‐CYPRESS: A POTENTIAL HYDROECOLOGICAL INDICATOR OF GROUND WATER PERTURBATIONS1
Authors: Bacchus Sydney T , Hamazaki Toshihide , Britton Kerry O. , Haines Bruce L.
Published: June 2007

ABSTRACT: Pond‐cypress, a deciduous conifer, is a dominant canopy species in depressional wetlands of the southeastern Coastal Plain (SCP). Extensive premature decline and death of pond‐cypress trees in central Florida have been attributed to hydroperiod alterations due to excessive withdrawals of ground water from the Floridan aquifer. One factor identified in the decline process is basal decay, which may be related to the presence of Botryosphaeria rhodina and Fusarium species (nonaggressive, facultative fungal pathogens). These fungi have been cultured from sapwood tissue of declining pond‐cypress associated with ground water mining, but not from pond‐cypress away from ground water mimng areas. In this experiment, differences in soluble (nonstructural) carbohydrate composition of branch tips were evaluated for one‐and two‐year old, nursery‐grown (unsheltered) pond‐cypress, following a year of growth under treatment conditions (control, fungal inoculation, water stress, and fungal inoculation plus water stress) in a growth chamber. Results from two methods of wet chemical analysis were compared (trimethylsilyl methylglycoside‐Method A, and alditol acetate ‐ Method B). Three pentoses (arabinose, rhamnose, and xylose) and three hexoses (galactose, glucose, and mannose) were identified in branch tips from both age classes. A fourth hexose (fucose) also was identified in samples from the younger trees. The acidic sugar, galacturonic acid, was identified in both age classes using Method A. Results suggest that prolonged water stress is correlated with greater relative concentrations of the neutral soluble sugars rhamnose (P = 0.02), xylose (P = 0.02), and galactose (P = 0.02), in addition to the acidic sugar galacturonic acid (P = 0.01), for Method A, and arabinose (P = 0.02) for Method B. These results also suggest that in the absence of water stress, the fungal pathogen B. rhodina does not penetrate to the sapwood of the trees, and that inoculation with this fungal pathogen is not correlated with differences in relative concentrations of nonstructural, soluble carbohydrates, based on Method A analysis. Empirical evidence suggests that pond‐cypress trees in depressional wetlands respond similarly to anthropogenic perturbations of ground water, but not to natural periods of drought in the absence of such perturbations. Therefore, pond‐cypress appear to be integrators of groundwater perturbations. Greater concentrations of the soluble sugars identified in this study in pond‐cypress branch tips may be hydroecological indicators of such anthropogenic perturbations as unsustainable yield from the regional aquifer and adverse impacts from aquifer storage and recovery (ASR) activities in the SCP.
EVALUATION OF SELECTED PESTICIDES IN NORTH CAROLINA SURFACE WATER SUPPLIES: INTAKE STUDY1
Authors: Holman Robert E. , Leidy Ross B. , Walker Ashlee E.
Published: June 2007

ABSTRACT: Studies were conducted to analyze the presence of 11 selected pesticides in 12 surface water supply intakes in the Piedmont and coastal plain regions of North Carolina. Samples were assayed using enzyme linked immunosorbent assays (ELISAs). Samples with pesticide detection of 1 μg/L or greater were extracted and confirmed using gas chromatography/mass spectrometry (GC/MS). Detection limits of the immunosorbent assays for pesticide residues were generally an order of magnitude higher than GC/MS. Atrazine was detected in approximately 45 percent of the samples, and on two occasions was at or above the lifetime Maximum Contaminant Level of 3.0 μg/L set by the Environmental Protection Agency for an annual average in finished drinking water. Metolachlor was detected in 58 percent of the samples. Of the remaining nine pesticides, including carbaryl, aldicarb, 2,4‐D, chiorpyrifos, acetochlor, methomyl, carbofuran, alachlor, and chlorothalonil, only aldicarb, 2,4‐D, and chlorpyrifos were detected in less than 9 percent of the samples for each pesticide.
FROZEN SOIL IMPACT ON GROUND WATER‐SURFACE WATER INTERACTION1
Authors: Daniel John A. , Staricka James A.
Published: June 2007

ABSTRACT: Ground water and surface water interaction in the prairie pothole region of the United States and Canada is seasonally dominated by the presence of thick, frozen soil layers that affect infiltration. During a spring thaw, the subsoil may remain frozen, preventing infiltration. The impact of the frozen soil layer on the timing of infiltration of depressional‐focused recharge to the ground water is not clearly understood. The objective of this paper is to relate changes in the water table during spring to changes in frost depth and soil water content. A depression and adjacent upland study site were instrumented with CRREL‐type frost tubes, neutron probe access tubes, and ground water monitoring wells. Increases in water table levels in a depression occurred before the frost layer decomposed and infiltrating water quickly formed a recharge mound. Water table responses at the upland site took place as two events. The first event was a gradual rise, probably caused by the lateral dissemination of the recharge mound. The second rise was a rapid rise coinciding with the decomposition of the soil frost layer. Because of the accumulation of surface water in depressions, agricultural practices that remove water from a field can affect water resources management by limiting the addition of water recharge to unconfmed ground water.
RECIRCULATING WELLS: GROUND WATER REMEDIATION AND PROTECTION OF SURFACE WATER RESOURCES1
Authors: Ryan Keith W. , Dwight Donald M. , Hlousek Douglas A.
Published: June 2007

ABSTRACT: Several chlorinated solvent plumes threaten the sole‐source aquifer underlying the Massachusetts Military Reservation at the western end of Cape Cod. Sensitive surface water features including ponds, cranberry bogs, and coastal wetlands are hydraulically connected to the aquifer. For one of the plumes (CS‐10 the original remedy of 120 extraction and reinjection wells has the potential for significant disruption of surface water hydrology, through the localized drawdown and mounding of the water table. Recirculating wells with in‐well air stripping offer a cost‐effective alternative to conventional pump‐and‐treat technology that does not adversely affect the configuration of the water table. Pilot testing of a two well system, pumping 300 gpm, showed a capture radius of > 200 feet per well, in‐well trichloroethylene (TCE) removal efficiencies of 92 to 98 percent per recirculation cycle, an average of three recirculation cycles within the capture zone, and no measurable effect on water table elevations at any point within the recirculation/treatment zone. During 120 days of operation, the mean concentration of TCE in the treatment zone was reduced by 83 percent, from 1,111 μg/l to 184 μg/l. Full‐scale design projections indicate that 60 wells at an average spacing of 160 feet, having an aggregate recirculation 11 MGD, can contain the CS‐b plume without ground water extraction or adverse hydraulic effects on surface water resources. The estimated capital costs for such a system are about $7 million, and annual operations‐and‐maintenance costs should be about $1.4 million, 40 percent of those associated with a pump and treat system over a 20‐year period.
INTEGRATING DEMOGRAPHIC AND LANDSAT (TM) DATA AT A WATERSHED SCALE1
Authors: Kuczenski Tracy K , Field Donald R. , Voss Paul R. , Radeloff Volker C. , Hagen Alice E.
Published: June 2007

ABSTRACT:Recurrent calls for integrated resource management urge that an understanding of human activities and populations be incorporated into natural resource research, management, and protection efforts. In this paper, we hypothesize that watersheds can be a valuable geography for organizing an inquiry into the relationship between humans and the environment, and we present a framework for conducting such efforts. The framework is grounded in the emerging field of landscape ecology and incorporates demographic theory and data. Demography has been advanced by technological capabilities associated with the 1990 Census. Employing Geographic Information System (GIS) tools, we couple Landsat Thematic Mapper (TM) land cover data with census‐derived housing density data to demonstrate the operation of our framework and its utility for better understanding human‐landscape interactions. In our investigation of the Kickapoo Watershed and two sub‐ watersheds, located in southwestern Wisconsin, we identify relationships between landscape composition and the distribution and social structure of human populations. Our findings offer insight into the interplay between people and biophysical systems.
GLOBAL CLIMATE CHANGE AND PUBLIC PERCEPTION: THE CHALLENGE OF TRANSLATION1
Authors: Seacrest Susan , Kuzelka Robert , Leonard Rick
Published: June 2007

ABSTRACT: Global climate change is examined from the perspective of its relevancy and urgency as a public policy issue. Interpreting from literature specific to investigations into public awareness and concern, climate change is seen as a legitimate though less than urgent issue. The literature reveals that the general public holds surprising misconceptions about the processes contributing to climate change, including failure to grasp the fundamental connection to CO2. General ambivalence is also suggested from the results of two surveys conducted by The Groundwater Foundation. They first asked participants in a recent Groundwater Guardian Conference to rate levels of discussion and concern for water resources implications in the participants' communities. A second survey polled national water resource organizations about the extent climate change has been a focus of their educational, investigative, or advocacy efforts. The paper concludes by describing basic barriers to stimulating public response to climate change, which education about the issue should address, and by offering a model to educate and involve citizens based on the Groundwater Guardian program developed by the The Groundwater Foundation.
IMPACTS OF CLIMATE CHANGE ON WATER YIELD IN THE UPPER WIND RIVER BASIN1
Authors: Stonefelt Michael D. , Fontaine Thomas A. , Hotchkiss Rollin H.
Published: June 2007

ABSTRACT: The potential impacts of climate change on water yield are examined in the Upper Wind River Basin. This is a high‐elevation, mountain basin with a snowfall/snowmelt dominated stream‐flow hydrograph. A variety of physiographic conditions are represented in the rangeland, coniferous forests, and high‐elevation alpine regions. The Soil Water Assessment Tool (SWAT) is used to model the baseline input time series data and climate change scenarios. Five hydroclimatic variables (temperature, precipitation, CO2, radiation, and humidity) are examined using sensitivity tests of individual and coupled variables with a constant change and coupled variables with a monthly change. Results indicate that the most influential variable on annual water yield is precipitation; and, the most influential variable on the timing of streamflow is temperature. Carbon dioxide, radiation, and humidity each noticeably impact water yield, but less significantly. The coupled variable analyses represent a more realistic climate change regime and reflect the combined response of the basin to each variable; for example, increased temperature offsets the effects of increased precipitation and magnifies the effects of decreased precipitation. This paper shows that the hydrologic response to climate change depends largely on the hydroclimatic variables examined and that each variable has a unique effect (e.g., magnitude, timing) on water yield.
CLIMATE CHANGE IMPACTS ON THE HYDROLOGY AND PRODUCTIVITY OF A PINE PLANTATION1
Authors: Sun Ge , Amatya Devendra M. , McNulty Steven G. , Skaggs R. Wayne , Hughes Joseph H.
Published: June 2007

ABSTRACT:There are increasing concerns in the forestry community about global climate change and variability associated with elevated atmospheric CO2. Changes in precipitation and increases in air temperature could impose additional stress on forests during the next century. For a study site in Carteret County, North Carolina, the General Circulation Model, HADCM2, predicts that by the year 2099, maximum air temperature will increase 1.6 to 1.9°C, minimum temperature will increase 2.5 to 2.8°C, and precipitation will increase 0 to 10 percent compared to the mid‐1990s. These changes vary from season to season. We utilized a forest ecosystem process model, PnET‐II, for studying the potential effects of climate change on drainage outflow, evapotranspiration, leaf area index (LAI) and forest Net Primary Productivity (NPP). This model was first validated with long term drainage and LAI data collected at a 25‐ha mature loblolly pine (Pinus taedaL.) experimental watershed located in the North Carolina lower coastal plain. The site is flat with poorly drained soils and high groundwater table. Therefore, a high field capacity of 20 cm was used in the simulation to account for the topographic effects. This modeling study suggested that future climate change would cause a significant increase of drainage (6 percent) and forest productivity (2.5 percent). Future studies should consider the biological feedback (i.e., stomata conductance and water use efficiency) to air temperature change.