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Many aquatic ecosystems are experiencing multiple anthropogenic stressors that threaten their ability to support ecologically and economically important fish species. Two of the most ubiquitous stressors are climate change and non‐point source nutrient pollution. Agricultural conservation practices (ACPs, i.e. farming practices that reduce runoff, prevent erosion, and curb excessive nutrient loading) offer a potential means to mitigate the negative effects of non‐point source pollution on fish populations. However, our understanding of how ACP implementation amidst a changing climate will affect fish production in large ecosystems that receive substantial upstream sediment and nutrient inputs remains incomplete. Towards this end, we explored how anticipated climate change and the implementation of realistic ACPs might alter the recruitment dynamics of three fish populations (native walleye Sander vitreus and yellow perch Perca flavescens and invasive white perch Morone americana) in the highly productive, dynamic west basin of Lake Erie. We projected future (2020–2065) recruitment under different combinations of anticipated climate change (n = 2 levels) and ACP implementation (n = 4 levels) in the western Lake Erie catchment using predictive biological models driven by forecasted winter severity, spring warming rate, and Maumee River total phosphorus loads that were generated from linked climate, catchment‐hydrology, and agricultural‐practice‐simulation models. In general, our models projected reduced walleye and yellow perch recruitment whereas invasive white perch recruitment was projected to remain stable or increase relative to the recent past. Our modelling also suggests the potential for trade‐offs, as ACP implementation was projected to reduce yellow perch recruitment with anticipated climate change. Overall, our study presents a useful modelling framework to forecast fish recruitment in Lake Erie and elsewhere, as well as offering projections and new avenues of research that could help resource management agencies and policy‐makers develop adaptive and resilient management strategies in the face of anticipated climate and land‐management change.
David A. Dippold; Noel R. Aloysius; Steven Conor Keitzer; Haw Yen; Jeffrey G. Arnold; Prasad Daggupati; Michael E. Fraker; Jay F. Martin; Dale M. Robertson; Scott P. Sowa; Mari‐Vaughn V. Johnson; Mike J. White; Stuart A. Ludsin. Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie. Freshwater Biology 2020, 65, 1487 -1508.
AMA StyleDavid A. Dippold, Noel R. Aloysius, Steven Conor Keitzer, Haw Yen, Jeffrey G. Arnold, Prasad Daggupati, Michael E. Fraker, Jay F. Martin, Dale M. Robertson, Scott P. Sowa, Mari‐Vaughn V. Johnson, Mike J. White, Stuart A. Ludsin. Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie. Freshwater Biology. 2020; 65 (9):1487-1508.
Chicago/Turabian StyleDavid A. Dippold; Noel R. Aloysius; Steven Conor Keitzer; Haw Yen; Jeffrey G. Arnold; Prasad Daggupati; Michael E. Fraker; Jay F. Martin; Dale M. Robertson; Scott P. Sowa; Mari‐Vaughn V. Johnson; Mike J. White; Stuart A. Ludsin. 2020. "Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie." Freshwater Biology 65, no. 9: 1487-1508.
This study is a part of the Conservation Effects Assessment Project (CEAP) aimed to quantify the environmental and economic benefits of conservation practices implemented in the cultivated cropland throughout the United States. The Soil and Water Assessment Tool (SWAT) model under the Hydrologic United Modeling of the United States (HUMUS) framework was used in the study. An automated flow calibration procedure was developed and used to calibrate runoff for each 8-digit watershed (within 20% of calibration target) and the partitioning of runoff into surface and sub-surface flow components (within 10% of calibration target). Streamflow was validated at selected gauging stations along major rivers within the river basin with a target R2 of >0.6 and Nash and Sutcliffe Efficiency of >0.5. The study area covered the entire Mississippi and Atchafalaya River Basin (MARB). Based on the results obtained, our analysis pointed out multiple challenges to calibration such as: (1) availability of good quality data, (2) accounting for multiple reservoirs within a sub-watershed, (3) inadequate accounting of elevation and slopes in mountainous regions, (4) poor representation of carrying capacity of channels, (5) inadequate capturing of the irrigation return flows, (6) inadequate representation of vegetative cover, and (7) poor representation of water abstractions (both surface and groundwater). Additional outstanding challenges to large-scale hydrologic model calibration were the coarse spatial scale of soils, land cover, and topography.
Narayanan Kannan; Chinnasamy Santhi; Michael J. White; Sushant Mehan; Jeffrey G. Arnold; Philip W. Gassman. Some Challenges in Hydrologic Model Calibration for Large-Scale Studies: A Case Study of SWAT Model Application to Mississippi-Atchafalaya River Basin. Hydrology 2019, 6, 17 .
AMA StyleNarayanan Kannan, Chinnasamy Santhi, Michael J. White, Sushant Mehan, Jeffrey G. Arnold, Philip W. Gassman. Some Challenges in Hydrologic Model Calibration for Large-Scale Studies: A Case Study of SWAT Model Application to Mississippi-Atchafalaya River Basin. Hydrology. 2019; 6 (1):17.
Chicago/Turabian StyleNarayanan Kannan; Chinnasamy Santhi; Michael J. White; Sushant Mehan; Jeffrey G. Arnold; Philip W. Gassman. 2019. "Some Challenges in Hydrologic Model Calibration for Large-Scale Studies: A Case Study of SWAT Model Application to Mississippi-Atchafalaya River Basin." Hydrology 6, no. 1: 17.
Decision tables have been used for many years in data processing and business applications to simulate complex rule sets. Several computer languages have been developed based on rule systems and they are easily programmed in several current languages. Land management and river–reservoir models simulate complex land management operations and reservoir management in highly regulated river systems. Decision tables are a precise yet compact way to model the rule sets and corresponding actions found in these models. In this study, we discuss the suitability of decision tables to simulate management in the river basin scale Soil and Water Assessment Tool (SWAT+) model. Decision tables are developed to simulate automated irrigation and reservoir releases. A simple auto irrigation application of decision tables was developed using plant water stress as a condition for irrigating corn in Texas. Sensitivity of the water stress trigger and irrigation application amounts were shown on soil moisture and corn yields. In addition, the Grapevine Reservoir near Dallas, Texas was used to illustrate the use of decision tables to simulate reservoir releases. The releases were conditioned on reservoir volumes and flood season. The release rules as implemented by the decision table realistically simulated flood releases as evidenced by a daily Nash–Sutcliffe Efficiency (NSE) of 0.52 and a percent bias of −1.1%. Using decision tables to simulate management in land, river, and reservoir models was shown to have several advantages over current approaches, including: (1) mature technology with considerable literature and applications; (2) ability to accurately represent complex, real world decision-making; (3) code that is efficient, modular, and easy to maintain; and (4) tables that are easy to maintain, support, and modify.
Jeffrey G. Arnold; Katrin Bieger; Michael J. White; Raghavan Srinivasan; John A. Dunbar; Peter M. Allen. Use of Decision Tables to Simulate Management in SWAT+. Water 2018, 10, 713 .
AMA StyleJeffrey G. Arnold, Katrin Bieger, Michael J. White, Raghavan Srinivasan, John A. Dunbar, Peter M. Allen. Use of Decision Tables to Simulate Management in SWAT+. Water. 2018; 10 (6):713.
Chicago/Turabian StyleJeffrey G. Arnold; Katrin Bieger; Michael J. White; Raghavan Srinivasan; John A. Dunbar; Peter M. Allen. 2018. "Use of Decision Tables to Simulate Management in SWAT+." Water 10, no. 6: 713.
Vegetative filter strips (VFS) are popular conservation practices installed at the edges of agricultural fields to reduce losses of pollutants from agricultural areas to receiving waterbodies. The recent interest in using VFS areas as multifunctional landscapes necessitates an improved depiction of VFS in simulation models. This study is aimed to enhance the physical representation of VFS in the Soil and Water Assessment Tool (SWAT) to improve the representation of ecohydrologic processes and land management practices in VFS areas. The proposed enhancement enables routing of water, sediment, and nutrients from the source area through the VFS area and makes the infiltrated water and nutrients available for filter crop uptake. The improvements are implemented in SWAT by modifying input files through Matlab scripts and by changing SWAT subroutines to enable routing. The model improvements are tested with three paired watershed studies with and without edge-of-field VFS in central Iowa. The improved model estimated 46% runoff reduction, 91% sediment reduction, 83% total phosphorus reduction, and 54% nitrate reduction with VFS, and these estimates closely matched the measured VFS reductions. The improved model was able to represent increased infiltration, soil moisture, and denitrification in the VFS area, along with accurately capturing crop yields in the source and VFS areas. Overall, the results indicate improved physical representation of VFS in SWAT. Keywords: Conservation measures, Flexible buffer strips, Multifunctional buffers, SWAT model, Vegetative filter strips.
Raj Cibin; Indrajeet Chaubey; Matthew J. Helmers; K. P. Sudheer; Michael J. White; Jeffrey G. Arnold. An Improved Representation of Vegetative Filter Strips in SWAT. Transactions of the ASABE 2018, 61, 1017 -1024.
AMA StyleRaj Cibin, Indrajeet Chaubey, Matthew J. Helmers, K. P. Sudheer, Michael J. White, Jeffrey G. Arnold. An Improved Representation of Vegetative Filter Strips in SWAT. Transactions of the ASABE. 2018; 61 (3):1017-1024.
Chicago/Turabian StyleRaj Cibin; Indrajeet Chaubey; Matthew J. Helmers; K. P. Sudheer; Michael J. White; Jeffrey G. Arnold. 2018. "An Improved Representation of Vegetative Filter Strips in SWAT." Transactions of the ASABE 61, no. 3: 1017-1024.
Soil samples were obtained from under actively growing Austrian winter peas and from 2 m away in a plot that had no winter peas or other legumes growing in its cover crop mix. Soils were treated with 5 carbon (C) compounds (oxalic, malic, citric, glycine and arginine) and a control (deionized water). Microbial response was measured using an automated soil respiration system (ASRS). The soil under winter peas evolved a higher amount of CO2 than the soil without winter peas across all treatments. The winter peas soil showed an increased response to oxalic and citric acids indicating that these compounds may be released by winter peas and that the microbial community is adept at assimilating them. We may be able to determine the C compounds and associated vegetation to which the indigenous microbial population is frequently exposed. Cover crop recommendations may be made based on microbial response rates to increase the diversity of the microbial community and health of the soil.
Richard L. Haney; Elizabeth B. Haney; Michael J. White; Uglas R. Smith. Soil CO 2 response to organic and amino acids. Applied Soil Ecology 2017, 125, 297 -300.
AMA StyleRichard L. Haney, Elizabeth B. Haney, Michael J. White, Uglas R. Smith. Soil CO 2 response to organic and amino acids. Applied Soil Ecology. 2017; 125 ():297-300.
Chicago/Turabian StyleRichard L. Haney; Elizabeth B. Haney; Michael J. White; Uglas R. Smith. 2017. "Soil CO 2 response to organic and amino acids." Applied Soil Ecology 125, no. : 297-300.
Model-based water quality assessments are an important informer of conservation and environmental policy in the U.S. The recently completed national scale Conservation Effects Assessment Project (CEAP) is being replicated using an improved model populated with new and higher resolution data. National assessments are particularly difficult as models must operate with both a very large spatial extent (the contiguous U.S.) while maintaining a level of granularity required to capture important small scale processes. In this research, we developed datasets to describe the hydrologic connectivity at the U.S. Geological Survey (USGS) 12-digit Hydrologic Unit Code (HUC-12) level. Connectivity between 86,000 HUC-12s as provided by the Watershed Boundary Dataset (WBD) was evaluated and corrected. We also detailed a method to resolve the highly detailed National Hydrography Dataset (NHD) stream segments within each HUC-12 into vastly simplified representative channel schemes suitable for use in the recently developed Soil and Water Assessment Tool + (SWAT+) model. This representative channel approach strikes a balance between computational complexity and accurate representation of the hydrologic system. These data will be tested in the upcoming CEAP II national assessment. Until then, all the WBD corrections and NHDPlus representative channel data are provided via the web for other researchers to evaluate and utilize.
Michael J. White; Katrin Beiger; Marilyn Gambone; Elizabeth Haney; Jeff Arnold; Jungang Gao. Development of a Hydrologic Connectivity Dataset for SWAT Assessments in the US. Water 2017, 9, 892 .
AMA StyleMichael J. White, Katrin Beiger, Marilyn Gambone, Elizabeth Haney, Jeff Arnold, Jungang Gao. Development of a Hydrologic Connectivity Dataset for SWAT Assessments in the US. Water. 2017; 9 (11):892.
Chicago/Turabian StyleMichael J. White; Katrin Beiger; Marilyn Gambone; Elizabeth Haney; Jeff Arnold; Jungang Gao. 2017. "Development of a Hydrologic Connectivity Dataset for SWAT Assessments in the US." Water 9, no. 11: 892.
The proper representation of conservation practices on agricultural lands is an important factor in large-scale assessments of water quality in the United States. Unfortunately, there are few publicly available data sources at the local level and even fewer at the national scale. In this research, randomly selected points within agricultural lands were examined for selected conservation practices using Google Earth aerial imagery by a team of interpreters. In total, 13,530 points had field boundaries digitized, and were subsequently examined and classified. The presence of terraces, grassed waterways, contour farming, center pivot irrigation, strip cropping, ponds, riparian vegetation, filter strips, and land cover were noted. Subjectivity among interpreters was evaluated using duplicate samples and was found to be similar to image misclassification rates in other research. Conservation practice adoption rates for selected major river basins compared favorably with data collected by the Conservation Effects Assessment Project. The frequency of occurrence of each conservation practice was summarized and presented by ecoregion. To facilitate future research, point level data and software source code developed in this research are available via the web at http://nlet.brc.tamus.edu/Conservation. Aerial imagery was found to be a powerful, inexpensive, and easily accessible tool to assess large-scale conservation practice implementation for certain conservation practices.
Michael White; Leighton Haglund; Marcus Gloe; Katrin Bieger; Brandon Namphong; Marilyn Gambone; Eric Hardy; Jungang Gao; Haw Yen; Jeff Arnold. Distribution of Selected Soil and Water Conservation Practices in the U.S. as Identified with Google Earth. JAWRA Journal of the American Water Resources Association 2017, 53, 1229 -1240.
AMA StyleMichael White, Leighton Haglund, Marcus Gloe, Katrin Bieger, Brandon Namphong, Marilyn Gambone, Eric Hardy, Jungang Gao, Haw Yen, Jeff Arnold. Distribution of Selected Soil and Water Conservation Practices in the U.S. as Identified with Google Earth. JAWRA Journal of the American Water Resources Association. 2017; 53 (5):1229-1240.
Chicago/Turabian StyleMichael White; Leighton Haglund; Marcus Gloe; Katrin Bieger; Brandon Namphong; Marilyn Gambone; Eric Hardy; Jungang Gao; Haw Yen; Jeff Arnold. 2017. "Distribution of Selected Soil and Water Conservation Practices in the U.S. as Identified with Google Earth." JAWRA Journal of the American Water Resources Association 53, no. 5: 1229-1240.
Water quality simulation models such as the Soil and Water Assessment Tool (SWAT) and Agricultural Policy EXtender (APEX) are widely used in the US. These models require large amounts of spatial and tabular data to simulate the natural world. Accurate and seamless daily climatic data are critical for accurate depiction of the hydrologic cycle, yet these data are among the most difficult to obtain and process. In this paper we describe the development of a national (US) database of preprocessed climate data derived from monitoring stations applicable to USGS 12-digit watersheds. Various sources and processing methods are explored and discussed. A relatively simple method was employed to choose representative stations for each of the 83,000 12-digit watersheds in the continental US. Fully processed climate data resulting from this research were published online to facilitate other SWAT and APEX modeling efforts in the US.
Michael J. White; Marilyn Gambone; Elizabeth Haney; Jeffrey Arnold; Jungang Gao. Development of a Station Based Climate Database for SWAT and APEX Assessments in the US. Water 2017, 9, 437 .
AMA StyleMichael J. White, Marilyn Gambone, Elizabeth Haney, Jeffrey Arnold, Jungang Gao. Development of a Station Based Climate Database for SWAT and APEX Assessments in the US. Water. 2017; 9 (6):437.
Chicago/Turabian StyleMichael J. White; Marilyn Gambone; Elizabeth Haney; Jeffrey Arnold; Jungang Gao. 2017. "Development of a Station Based Climate Database for SWAT and APEX Assessments in the US." Water 9, no. 6: 437.
The Soil and Water Assessment Tool 2012 (SWAT2012) offers four sediment routing methods as optional alternatives to the default simplified Bagnold method. Previous studies compared only one of these alternative sediment routing methods with the default method. The proposed study evaluated the impacts of all four alternative sediment transport methods on sediment predictions: the modified Bagnold equation, the Kodoatie equation, the Molinas and Wu equation, and the Yang equation. The Arroyo Colorado Watershed, Texas, USA, was first calibrated for daily flow. The sediment parameters were then calibrated to monthly sediment loads, using each of the four sediment routing equations. An automatic calibration tool—Integrated Parameter Estimation and Uncertainty Analysis Tool (IPEAT)—was used to fit model parameters. The four sediment routing equations yielded substantially different sediment sources and sinks. The Yang equation performed best, followed by Kodoatie, Bagnold, and Molinas and Wu equations, according to greater model goodness-of-fit (represented by higher Nash–Sutcliffe Efficiency coefficient and percent bias closer to 0) as well as lower model uncertainty (represented by inclusion of observed data within 95% confidence interval). Since the default method (Bagnold) does not guarantee the best results, modelers should carefully evaluate the selection of alternative methods before conducting relevant studies or engineering projects.
Haw Yen; Shenglan Lu; Qingyu Feng; Ruoyu Wang; Jungang Gao; Dawn Michelle Brady; Amirreza Sharifi; Jungkyu Ahn; Shien-Tsung Chen; Jaehak Jeong; Michael James White; Jeffrey George Arnold. Assessment of Optional Sediment Transport Functions via the Complex Watershed Simulation Model SWAT. Water 2017, 9, 76 .
AMA StyleHaw Yen, Shenglan Lu, Qingyu Feng, Ruoyu Wang, Jungang Gao, Dawn Michelle Brady, Amirreza Sharifi, Jungkyu Ahn, Shien-Tsung Chen, Jaehak Jeong, Michael James White, Jeffrey George Arnold. Assessment of Optional Sediment Transport Functions via the Complex Watershed Simulation Model SWAT. Water. 2017; 9 (2):76.
Chicago/Turabian StyleHaw Yen; Shenglan Lu; Qingyu Feng; Ruoyu Wang; Jungang Gao; Dawn Michelle Brady; Amirreza Sharifi; Jungkyu Ahn; Shien-Tsung Chen; Jaehak Jeong; Michael James White; Jeffrey George Arnold. 2017. "Assessment of Optional Sediment Transport Functions via the Complex Watershed Simulation Model SWAT." Water 9, no. 2: 76.
The soil extractant, H3A, has undergone several iterations to extract calcium (Ca), iron (Fe), aluminum (Al), potassium (K), phosphorus (P), ammonium (NH4-N) and nitrate (NO3-N) under ambient soil conditions. Few soil extractants currently used by commercial and university soil testing laboratories can perform multi-nutrient extraction without over- or under-estimating at least one nutrient. Soil pH and plant root exudates have a strong influence on nutrient availability and H3A was developed to mimic soil conditions. Lithium citrate was previously used in the H3A formulation, but resulted in a cloudy supernatant in some samples, complicating laboratory analyses. In this study, we removed lithium citrate and compared the nutrients extracted from the modified (H3A-4) to the established (H3A-3) solutions. We found that the new extractant, H3A-4, produced a clear supernatant even in soils with low pH and high iron and aluminum concentrations. H3A-4 accurately predicts plant available nutrients and is a viable choice for commercial and laboratory settings due to its ease of use.
Richard L. Haney; Elizabeth B. Haney; Douglas R. Smith; Michael J. White. Removal of Lithium Citrate from H3A for Determination of Plant Available P. Open Journal of Soil Science 2017, 07, 301 -314.
AMA StyleRichard L. Haney, Elizabeth B. Haney, Douglas R. Smith, Michael J. White. Removal of Lithium Citrate from H3A for Determination of Plant Available P. Open Journal of Soil Science. 2017; 07 (11):301-314.
Chicago/Turabian StyleRichard L. Haney; Elizabeth B. Haney; Douglas R. Smith; Michael J. White. 2017. "Removal of Lithium Citrate from H3A for Determination of Plant Available P." Open Journal of Soil Science 07, no. 11: 301-314.
SWAT+ is a completely restructured version of the Soil and Water Assessment Tool (SWAT) that was developed to face present and future challenges in water resources modeling and management and to meet the needs of the worldwide user community. It is expected to improve code development and maintenance; support data availability, analysis, and visualization; and enhance the model's capabilities in terms of the spatial representation of elements and processes within watersheds. The most important change is the implementation of landscape units and flow and pollutant routing across the landscape. Also, SWAT+ offers more flexibility than SWAT in defining management schedules, routing constituents, and connecting managed flow systems to the natural stream network. To test the basic hydrologic function of SWAT+, it was applied to the Little River Experimental Watershed (Georgia) without enhanced overland routing and compared with previous models. SWAT+ gave similar results and inaccuracies as these models did for streamflow and water balance. Taking full advantage of the new capabilities of SWAT+ regarding watershed discretization and landscape and river interactions is expected to improve simulations in future studies. While many capabilities of SWAT have already been enhanced in SWAT+ and new capabilities have been added, the model will continue to evolve in response to advancements in scientific knowledge and the demands of the growing worldwide user community. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.
Katrin Bieger; Jeffrey G. Arnold; Hendrik Rathjens; Michael J. White; David D. Bosch; Peter M. Allen; Martin Volk; Raghavan Srinivasan. Introduction to SWAT+, A Completely Restructured Version of the Soil and Water Assessment Tool. JAWRA Journal of the American Water Resources Association 2016, 53, 115 -130.
AMA StyleKatrin Bieger, Jeffrey G. Arnold, Hendrik Rathjens, Michael J. White, David D. Bosch, Peter M. Allen, Martin Volk, Raghavan Srinivasan. Introduction to SWAT+, A Completely Restructured Version of the Soil and Water Assessment Tool. JAWRA Journal of the American Water Resources Association. 2016; 53 (1):115-130.
Chicago/Turabian StyleKatrin Bieger; Jeffrey G. Arnold; Hendrik Rathjens; Michael J. White; David D. Bosch; Peter M. Allen; Martin Volk; Raghavan Srinivasan. 2016. "Introduction to SWAT+, A Completely Restructured Version of the Soil and Water Assessment Tool." JAWRA Journal of the American Water Resources Association 53, no. 1: 115-130.
Complex watershed simulation models are powerful tools that can help scientists and policy-makers address challenging topics, such as land use management and water security. In the Western Lake Erie Basin (WLEB), complex hydrological models have been applied at various scales to help describe relationships between land use and water, nutrient, and sediment dynamics. This manuscript evaluated the capacity of the current Soil and Water Assessment Tool (SWAT) to predict hydrological and water quality processes within WLEB at the finest resolution watershed boundary unit (NHDPlus) along with the current conditions and conservation scenarios. The process based SWAT model was capable of the fine-scale computation and complex routing used in this project, as indicated by measured data at five gaging stations. The level of detail required for fine-scale spatial simulation made the use of both hard and soft data necessary in model calibration, alongside other model adaptations. Limitations to the model's predictive capacity were due to a paucity of data in the region at the NHDPlus scale rather than due to SWAT functionality. Results of treatment scenarios demonstrate variable effects of structural practices and nutrient management on sediment and nutrient loss dynamics. Targeting treatment to acres with critical outstanding conservation needs provides the largest return on investment in terms of nutrient loss reduction per dollar spent, relative to treating acres with lower inherent nutrient loss vulnerabilities. Importantly, this research raises considerations about use of models to guide land management decisions at very fine spatial scales. Decision makers using these results should be aware of data limitations that hinder fine-scale model interpretation.
Haw Yen; Michael J. White; Jeffrey G. Arnold; S. Conor Keitzer; Mari-Vaughn V. Johnson; Jay D. Atwood; Prasad Daggupati; Matthew E. Herbert; Scott P. Sowa; Stuart A. Ludsin; Dale M. Robertson; Raghavan Srinivasan; Charles A. Rewa. Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios. Science of The Total Environment 2016, 569-570, 1265 -1281.
AMA StyleHaw Yen, Michael J. White, Jeffrey G. Arnold, S. Conor Keitzer, Mari-Vaughn V. Johnson, Jay D. Atwood, Prasad Daggupati, Matthew E. Herbert, Scott P. Sowa, Stuart A. Ludsin, Dale M. Robertson, Raghavan Srinivasan, Charles A. Rewa. Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios. Science of The Total Environment. 2016; 569-570 ():1265-1281.
Chicago/Turabian StyleHaw Yen; Michael J. White; Jeffrey G. Arnold; S. Conor Keitzer; Mari-Vaughn V. Johnson; Jay D. Atwood; Prasad Daggupati; Matthew E. Herbert; Scott P. Sowa; Stuart A. Ludsin; Dale M. Robertson; Raghavan Srinivasan; Charles A. Rewa. 2016. "Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios." Science of The Total Environment 569-570, no. : 1265-1281.
Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical USGS water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34 percent and phosphorus reductions from 1 to 10 percent in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.
Ana María García; Richard Brown Alexander; Jeffrey G. Arnold; Lee Norfleet; Michael J. White; Dale M. Robertson; Gregory E. Schwarz. Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin. Environmental Science & Technology 2016, 50, 6991 -7000.
AMA StyleAna María García, Richard Brown Alexander, Jeffrey G. Arnold, Lee Norfleet, Michael J. White, Dale M. Robertson, Gregory E. Schwarz. Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin. Environmental Science & Technology. 2016; 50 (13):6991-7000.
Chicago/Turabian StyleAna María García; Richard Brown Alexander; Jeffrey G. Arnold; Lee Norfleet; Michael J. White; Dale M. Robertson; Gregory E. Schwarz. 2016. "Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin." Environmental Science & Technology 50, no. 13: 6991-7000.
In recent years, large-scale watershed modeling has been implemented broadly in the field of water resources planning and management. Complex hydrological, sediment, and nutrient processes can be simulated by sophisticated watershed simulation models for important issues such as water resources allocation, sediment transport, and pollution control. Among commonly adopted models, the Soil and Water Assessment Tool (SWAT) has been demonstrated to provide superior performance with a large amount of referencing databases. However, it is cumbersome to perform tedious initialization steps such as preparing inputs and developing a model with each changing targeted study area. In this study, the Hydrologic and Water Quality System (HAWQS) is introduced to serve as a national-scale Decision Support System (DSS) to conduct challenging watershed modeling tasks. HAWQS is a web-based DSS developed and maintained by Texas A & M University, and supported by the U.S. Environmental Protection Agency. Three different spatial resolutions of Hydrologic Unit Code (HUC8, HUC10, and HUC12) and three temporal scales (time steps in daily/monthly/annual) are available as alternatives for general users. In addition, users can specify preferred values of model parameters instead of using the pre-defined sets. With the aid of HAWQS, users can generate a preliminarily calibrated SWAT project within a few minutes by only providing the ending HUC number of the targeted watershed and the simulation period. In the case study, HAWQS was implemented on the Illinois River Basin, USA, with graphical demonstrations and associated analytical results. Scientists and/or decision-makers can take advantage of the HAWQS framework while conducting relevant topics or policies in the future.
Haw Yen; Prasad Daggupati; Michael J. White; Raghavan Srinivasan; Arndt Gossel; David Wells; Jeffrey G. Arnold. Application of Large-Scale, Multi-Resolution Watershed Modeling Framework Using the Hydrologic and Water Quality System (HAWQS). Water 2016, 8, 164 .
AMA StyleHaw Yen, Prasad Daggupati, Michael J. White, Raghavan Srinivasan, Arndt Gossel, David Wells, Jeffrey G. Arnold. Application of Large-Scale, Multi-Resolution Watershed Modeling Framework Using the Hydrologic and Water Quality System (HAWQS). Water. 2016; 8 (4):164.
Chicago/Turabian StyleHaw Yen; Prasad Daggupati; Michael J. White; Raghavan Srinivasan; Arndt Gossel; David Wells; Jeffrey G. Arnold. 2016. "Application of Large-Scale, Multi-Resolution Watershed Modeling Framework Using the Hydrologic and Water Quality System (HAWQS)." Water 8, no. 4: 164.
Michael White; Marilyn Gambone; Haw Yen; Prasad Daggupati; Katrin Bieger; Debjani Deb; Jeff Arnold. Development of a Cropland Management Dataset to Support U.S. Swat Assessments. JAWRA Journal of the American Water Resources Association 2015, 52, 269 -274.
AMA StyleMichael White, Marilyn Gambone, Haw Yen, Prasad Daggupati, Katrin Bieger, Debjani Deb, Jeff Arnold. Development of a Cropland Management Dataset to Support U.S. Swat Assessments. JAWRA Journal of the American Water Resources Association. 2015; 52 (1):269-274.
Chicago/Turabian StyleMichael White; Marilyn Gambone; Haw Yen; Prasad Daggupati; Katrin Bieger; Debjani Deb; Jeff Arnold. 2015. "Development of a Cropland Management Dataset to Support U.S. Swat Assessments." JAWRA Journal of the American Water Resources Association 52, no. 1: 269-274.
The Upper Trinity River Basin (TRB) is the most populated river basin and one of the largest water suppliers in Texas. However, sediment and nutrient loads are reducing the capacity of reservoirs and degrading water quality. The objectives of this study are to calibrate and validate the Soil and Water Assessment Tool (SWAT) model for ten study watersheds within the Upper TRB in order to assess nutrient loads into major reservoirs in the basin and to predict the effects of point source elimination and urbanization on nutrient loads through scenario analyses. SWAT performed reasonably well for the current condition except for two out of five tributaries in the Eagle Mountain watershed and total phosphorous OPEN ACCESS Water 2015, 7 5690 in Richland-Chambers. The impacts of simulated scenarios varied within watersheds. Point-source elimination achieved reductions ranging from 0.3% to 24% in total phosphorus and 1% to 56% in total nitrogen received by the reservoirs. Population and development projections were used to examine the impacts of urbanization on each watershed. Projected urbanization in 2030 had large effects on simulated total phosphorus loads in some watersheds, ranging from a reduction of 1% to an increase of 111%. Projected urbanization also affected simulated total nitrogen loads, from a reduction of 3% to an increase of 24%. One limitation of this study is the lack of long-term, up-to-date water quality data due to discontinued water-quality monitoring stations. Although careful considerations were given to the adjustment of parameter values reflecting various aspects of the nutrient processes, further data collection will enhance modeling study for assessment of these watersheds’ water resources and environmental problem.
Taesoo Lee; Xiuying Wang; Michael White; Pushpa Tuppad; Raghavan Srinivasan; Balaji Narasimhan; Darrel Andrews. Modeling Water-Quality Loads to the Reservoirs of the Upper Trinity River Basin, Texas, USA. Water 2015, 7, 5689 -5704.
AMA StyleTaesoo Lee, Xiuying Wang, Michael White, Pushpa Tuppad, Raghavan Srinivasan, Balaji Narasimhan, Darrel Andrews. Modeling Water-Quality Loads to the Reservoirs of the Upper Trinity River Basin, Texas, USA. Water. 2015; 7 (10):5689-5704.
Chicago/Turabian StyleTaesoo Lee; Xiuying Wang; Michael White; Pushpa Tuppad; Raghavan Srinivasan; Balaji Narasimhan; Darrel Andrews. 2015. "Modeling Water-Quality Loads to the Reservoirs of the Upper Trinity River Basin, Texas, USA." Water 7, no. 10: 5689-5704.
The availability of freshwater is a prerequisite for municipal development and agricultural production, especially in the arid and semiarid portions of the western United States (U.S.). Agriculture is the leading user of water in the U.S. Agricultural water use can be partitioned into green (derived from rainfall) and blue water (irrigation). Blue water can be further subdivided by source. In this research, we develop a hydrologic balance by 8-Digit Hydrologic Unit Code using a combination of Soil and Water Assessment Tool simulations and available human water use estimates. These data are used to partition agricultural groundwater usage by sustainability and surface water usage by local source or importation. These predictions coupled with reported agricultural yield data are used to predict the virtual water contained in each ton of corn, wheat, sorghum, and soybeans produced and its source. We estimate that these four crops consume 480 km3 of green water annually and 23 km3 of blue water, 12 km3 of which is from groundwater withdrawal. Regional trends in blue water use from groundwater depletion highlight heavy usage in the High Plains, and small pockets throughout the western U.S. This information is presented to inform water resources debate by estimating the cost of agricultural production in terms of water regionally. This research illustrates the variable water content of the crops we consume and export, and the source of that water.
Michael White; Marilyn Gambone; Haw Yen; Jeff Arnold; Daren Harmel; Chinnasamy Santhi; Richard Haney. Regional Blue and Green Water Balances and Use by Selected Crops in the U.S. JAWRA Journal of the American Water Resources Association 2015, 51, 1626 -1642.
AMA StyleMichael White, Marilyn Gambone, Haw Yen, Jeff Arnold, Daren Harmel, Chinnasamy Santhi, Richard Haney. Regional Blue and Green Water Balances and Use by Selected Crops in the U.S. JAWRA Journal of the American Water Resources Association. 2015; 51 (6):1626-1642.
Chicago/Turabian StyleMichael White; Marilyn Gambone; Haw Yen; Jeff Arnold; Daren Harmel; Chinnasamy Santhi; Richard Haney. 2015. "Regional Blue and Green Water Balances and Use by Selected Crops in the U.S." JAWRA Journal of the American Water Resources Association 51, no. 6: 1626-1642.
The objective of this study was to evaluate soil nutrient loading and depth distributions of extractable nitrogen (N), phosphorus (P), and potassium (K) after long-term, continuous annual surface applications of anaerobically digested class B biosolids at a municipal recycling facility in central Texas. Commercial forage production fields of coastal bermudagrass (Cynodon dactylon L.) were surface applied at 0, 20, 40, or 60 Mg dry biosolids ha−1 y−1 for 8 years. Application duration was evaluated in fields treated with 20 Mg dry biosolids ha−1 y−1 for 0, 8, or 20 years. Total soil loads of extractable inorganic N and P increased linearly with application rate, but only extractable P increased with duration. Neither total load nor soil distribution of extractable K was affected by biosolid applications. Mineralization of biosolid-derived organic N and P likely contributed to elevated concentrations of nitrate throughout the soil profile (0–110 cm) and orthophosphate in surface soils (0–40 cm).
Richard L. Haney; Virginia L. Jin; Mari-Vaughn V. Johnson; Michael J. White; Jeffrey G. Arnold. On-Site Assessment of Extractable Soil Nutrients after Long-Term Biosolid Applications to Perennial Forage. Communications in Soil Science and Plant Analysis 2015, 46, 873 -887.
AMA StyleRichard L. Haney, Virginia L. Jin, Mari-Vaughn V. Johnson, Michael J. White, Jeffrey G. Arnold. On-Site Assessment of Extractable Soil Nutrients after Long-Term Biosolid Applications to Perennial Forage. Communications in Soil Science and Plant Analysis. 2015; 46 (7):873-887.
Chicago/Turabian StyleRichard L. Haney; Virginia L. Jin; Mari-Vaughn V. Johnson; Michael J. White; Jeffrey G. Arnold. 2015. "On-Site Assessment of Extractable Soil Nutrients after Long-Term Biosolid Applications to Perennial Forage." Communications in Soil Science and Plant Analysis 46, no. 7: 873-887.
Water quality impairment due to excessive nutrients and sediment is a major problem in the United States (U.S.). An important step in the mitigation of impairment in any given water body is determination of pollutant sources and amount. The sheer number of impaired waters and limited resources makes simplistic load estimation methods such as export coefficient (EC) methods attractive. Unfortunately ECs are typically based on small watershed monitoring data, which are very limited and/or often based on data collected from distant watersheds with drastically different conditions. In this research, we seek to improve the accuracy of these nutrient export estimation methods by developing a national database of localized EC for each ecoregion in the U.S. A stochastic sampling methodology loosely based on the Monte‐Carlo technique was used to construct a database of 45 million Soil and Water Assessment Tool (SWAT) simulations. These simulations consider a variety of climate, topography, soils, weather, land use, management, and conservation implementation conditions. SWAT model simulations were successfully validated with edge‐of‐field monitoring data. Simulated nutrient ECs compared favorably with previously published studies. These ECs may be used to rapidly estimate nutrient loading for any small catchment in the U.S. provided the location, area, and land‐use distribution are known.
Michael White; Daren Harmel; Haw Yen; Jeff Arnold; Marilyn Gambone; Richard Haney. Development of Sediment and Nutrient Export Coefficients for U.S. Ecoregions. JAWRA Journal of the American Water Resources Association 2015, 51, 758 -775.
AMA StyleMichael White, Daren Harmel, Haw Yen, Jeff Arnold, Marilyn Gambone, Richard Haney. Development of Sediment and Nutrient Export Coefficients for U.S. Ecoregions. JAWRA Journal of the American Water Resources Association. 2015; 51 (3):758-775.
Chicago/Turabian StyleMichael White; Daren Harmel; Haw Yen; Jeff Arnold; Marilyn Gambone; Richard Haney. 2015. "Development of Sediment and Nutrient Export Coefficients for U.S. Ecoregions." JAWRA Journal of the American Water Resources Association 51, no. 3: 758-775.
Phosphorus loading and measurement is of concern on lands where biosolids have been applied. Traditional soil testing for plant-available P may be inadequate for the accurate assessment of P loadings in a regulatory environment as the reported levels may not correlate well with environmental risk. In order to accurately assess potential P runoff and leaching, as well as plant uptake, we must be able to measure organic P mineralized by the biotic community in the soil. Soils with varying rates of biosolid application were evaluated for mineralized organic P during a 112-day incubation using the difference between P measured using a rapid-flow analyzer (RFA) and an axial flow Varian ICP-OES. An increase in the P mineralized from the treated soils was observed from analysis with the Varian ICP-OES, but not with the RFA. These results confirm that even though organic P concentrations have increased due to increasing biosolid application, traditional soil testing using an RFA for detection, would not accurately portray P concentration and potential P loading from treated soils.
Richard L. Haney; Virginia L. Jin; Mari-Vaughn V. Johnson; Elizabeth B. Haney; R. Daren Harmel; Jeffrey G. Arnold; Michael J. White. Analysis Methods for the Determination of Anthropogenic Additions of P to Agricultural Soils. Open Journal of Soil Science 2015, 05, 59 -68.
AMA StyleRichard L. Haney, Virginia L. Jin, Mari-Vaughn V. Johnson, Elizabeth B. Haney, R. Daren Harmel, Jeffrey G. Arnold, Michael J. White. Analysis Methods for the Determination of Anthropogenic Additions of P to Agricultural Soils. Open Journal of Soil Science. 2015; 05 (02):59-68.
Chicago/Turabian StyleRichard L. Haney; Virginia L. Jin; Mari-Vaughn V. Johnson; Elizabeth B. Haney; R. Daren Harmel; Jeffrey G. Arnold; Michael J. White. 2015. "Analysis Methods for the Determination of Anthropogenic Additions of P to Agricultural Soils." Open Journal of Soil Science 05, no. 02: 59-68.