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Refinement and regionalization of phosphorus assessment tools in Mississippi
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Ramirez-Avila J.J., Oldham J.L., Ortega-Achury S.L., Osmond D., Martin J.L., Locke M., Read J.J.


Phosphorus is a major nonpoint source pollutant that causes eutrophication in surface waters. Phosphorus (P) Indices are applied assessment tools used to identify agricultural fields most vulnerable to P loss by accounting for major source and transport factors controlling P movement. There is a wide range in formulation and management recommendations of P Indices among the southern states leading to differences in P-management recommendations under relatively similar site conditions. This situation creates the need for rigorous evaluations of P Indices to determine directional and magnitudinal correctness. Mississippi State University-based investigators participate in a southern multistate research program with the objectives to coordinate and advance P management in the region by ensuring that P assessment tools developing using guidance in the 2011 NRCS 590 standard are compared to water quality data. The research goals include producing tools that provide more consistent results across physiographic regions that will encourage greater similarity between southern state P Index ratings and ensuing recommendations. Values of annual P loss measured in two Mississippi physiographic regions, i.e. agricultural fields in the Mississippi Delta and pastures in the poultry production counties in South Mississippi, are used to compare southern P Index assessments against water quality data, and to calibrate and validate the Agricultural Policy/Environmental eXtender (APEX) model. Results will show the assessment for P loss vulnerability estimated by different southern P Indices and the performance of the APEX model before and after calibration and validation procedures for the proposed scenarios.

Numerical Modeling of Flow and Mercury Distribution in Enid Lake, Mississippi
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Chao X., Hossain A.K., Cizdziel J., Jia Y.


The Yazoo River Basin is the largest basin in Mississippi. Four large flood control reservoirs: Arkabutla Lake, Sardis Lake, Enid Lake and Grenada Lake, are located in this region, providing significant natural and recreational resources. The soils in this region are highly erodible, resulting in a large amount of sediment discharged into the water bodies. Sediments are normally associated with many pollutants and greatly affect water quality and aquatic lives. Mercury concentrations in water, sediment and fish in Enid Lake are relatively high, and a fish consumption advisory was issued by Mississippi Department of Environmental Quality (MDEQ) in 1995. In this study, a numerical model was developed based on CCHE3D, a three-dimensional free surface hydrodynamic, sediment and water quality model to simulate the flow, sediment and mercury distributions in Enid Lake. Total mercury in water and sediment were simulated, and the major processes, including advection, diffusion, adsorption/desorption, bed release, atmosphere deposition, settling, etc., were considered in the model. This model was calibrated and validated using field measurements and remote sensing data. This model provides useful tools for understanding the fate and transport of mercury in natural lakes.

Developing Numeric Nutrient Criteria For Mississippi
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Young A., Caviness K.


Nutrient loads, including nitrogen and phosphorus, have been a major cause of impairments in water bodies nationwide. In 2001 the USEPA developed an Action Plan requiring that all states develop numeric nutrient criteria in order to protect uses from nutrient pollution. Since then, the Mississippi Department of Environmental Quality (MDEQ) has been active in pursing this goal, including creating a Nutrient Criteria Development Plan and collecting data to derive scientifically defensible nutrient criteria. A technical advisory group (TAG) consisting of members of state, federal, and research scientists has been formed to aid MDEQ in deriving these criteria with their technical knowledge and regional experience. The methods used to determine criteria are data compilation, classification of waters, and data analysis. In an effort to be more scientifically defensible, MDEQ is applying the multiple lives of evidence approach for nutrient criteria development. The multiple lines of evidence approach involves looking at several lines of analysis, such as distributional analysis, stressor-response, scientific literature, and water quality models to create a final endpoint. In addition to developing criteria, MDEQ recognizes that moving forward the implementation of these criteria is also a priority of the state. An implementation work group has been formed to address issues such as permits, assessment, total maximum daily loads (TMDLs), waste load allocations (WLAs), and watershed planning. The MDEQ, along with the support of the TAG and the involvement of stakeholders, are making great strides in developing criteria for the Mississippi's rivers, streams, lakes, coastal and Delta waters.

Leaching of copper from different copper treated woodwastes
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Singleton B., Borazjani H., Cox M.


There has been a significant increase in production of copper treated lumber since voluntary halt in production of chromated copper arsenate (CCA) for residential use by the wood treating industry. Disposal of copper treated wood wastes have become an environmental issue for companies using these products for residential applications. This study evaluated recovery of copper from sawdust of copper azole(CA),micronized copper azole(MCA), azole copper quat(ACQ), and micronized copper quat(MCQ) using two different extraction procedures(toxicity characteristic leaching procedure(TCLP), and sonication) in acidic water. No significant differences in copper recovery were observed between CA and MCA by both extraction procedures. The same results were observed for ACQ and MCQ also. However, copper recovery for MCQ and ACQ were significantly higher than CA, and MCA.

Diamondhead MS BMP Demonstration Site, Outreach Tools and Model Ordinance
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Gallo W.C.


Researchers at Mississippi State University along with the Mississippi Department of Environmental Quality (MDEQ) have developed new BMP demonstrations, educational outreach material and policy tools for coastal Mississippi. A proposal for a BMP demonstration site was developed that promotes resilient community design and development in Diamondhead, MS. The demonstration site is designed to accommodate future commercial development, protect watershed health, and demonstrate small and large scale structural BMPs from infiltration basins to regional detention. Two presentations and two brochures were also developed that focus on homeowners and policy makers. Both sets of documents are designed to provide a broad overview of the tools, policies and practices homeowners and policy makers can adapt to better protect their a home watershed and a community watershed. All documents will be available for use from the MDEQ to meet NPDES Phase II education and outreach requirements. Lastly, a new model ordinance was created based on a review of other model ordinances throughout the country and adapted for the specific needs of coastal Mississippi. The ordinance is designed to be flexible and adaptable to any community's requirements by providing options and insights into the choices available throughout the document. This document will also be available for municipalities use from the MDEQ.

The Migratory Bird Habitat Initiative: Managing Waterbird Habitats After The 2010 Gulf Oil Spill
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Kaminski R.M., Davis J.B., Webb L., Tapp J., Weegman M.M.


In response to the 2010 Deepwater Horizon Gulf Oil Spill, the USDA Natural Resources Conservation Service (NRCS) funded the Migratory Bird Habitat Initiative (MBHI), providing landowners in eight Gulf coastal states $40 M in cost-share assistance to manage wetland habitats for waterbirds inland from the spill through 1-3-year contracts. As part of the comprehensive MBHI, we quantified (1) waterbird use of MBHI managed (i.e., primarily artificial flooding), non-managed, and other wetlands and (2) potential food resources for these birds in wetlands in the Lower Mississippi Alluvial Valley (MAV). Managed Wetlands Reserve Program (WRP) lands received significantly greater use by waterbirds than passively or non-managed WRP easements. In Louisiana and Mississippi, nearly 3 times more dabbling ducks (Anatini) and all ducks combined (Anatinae) were observed on MBHI than on non-managed WRP wetlands. Additionally, waterbirds other than waterfowl and shorebirds were nearly twice more abundant on MBHI than non-managed WRP wetlands. In Arkansas and Missouri, MBHI wetlands attracted over 2 times more dabbling ducks than non-managed WRP wetlands. Concerning food abundance and habitat carrying capacity for waterbirds, MBHI wetlands in Louisiana and Mississippi contained =1.26 and =1.53 times more total seed biomass and biomass of seeds known to be eaten by waterfowl, respectively, than non-managed WRP wetlands. In Arkansas and Missouri, seed biomass during winter was 21% greater on MBHI wetlands than non-managed WRP wetlands. While no significant differences in aquatic invertebrate biomass or number of invertebrate families were detected between managed and non-managed WRP wetlands in Arkansas and Missouri, production of invertebrates during autumn was 3 times greater on MBHI wetlands than non-managed WRP wetlands. During winter, invertebrate biomass was approximately 40% greater on MBHI and non-managed WRP wetlands than public-owned managed wetlands in these states. Our evaluation implies that MBHI management increased waterbird use and potential foraging carrying capacity of WRP wetlands for waterbirds and possibly provided alternative habitats for these birds inland from oil impacted Gulf coastal wetlands. Continued financial incentives to landowners in the MAV and nationally to manage wetlands at conservation easements following restoration have the potential to increase contribution of private lands to waterbird habitat availability and carrying capacity.

Mississippi Water Resources Inventory & Projections for Economic Development
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Linhoss A., Balwebber J., Pote J.


Mississippi's water resources are an important part of the state's economy, environment, and quality of life. Water is an essential commodity and the importance of water to Mississippi's economy is clear given the number of economic sectors that rely on the resource (e.g. agriculture, industry, energy, and public supply). However, the economic value of water is in many ways immeasurable because (1) it provides life whose economic value is incalculable, (2) there many external factors that are often not accounted for in the market value of water (e.g. pollution and environmental impacts), (3) users often self-supply and do not pay a market value for the resource, and (4) water is a complex resource whose value depends on volume, timing, reliability, and quality. The objective of this research is to assess the value of Mississippi's water resources within an integrative environmental and economic development framework. Mississippi is blessed with rich water resources. The state has the second highest rate of annual rainfall in the continental U.S. and major ground water aquifers underlie 83% of the state. River flow through Mississippi is dominated by the Mississippi River which discharges an average of 723,000 cubic feet per second. When combined, the rest of the rivers in Mississippi discharge approximately 60,000 cubic feet per second, which is only 7% of the flow in the Mississippi River. Eight dams in the state (0.2%) have the primary purpose of water supply and Mississippi has the least number of reservoirs with the purpose of water supply, relative to neighboring states. Mississippi's water use is dominated by groundwater and agriculture. 32% of Mississippi's water withdrawal permits are from surface water and the remaining 68% are from ground water. Irrigation for agriculture is the primary groundwater beneficial use category and industry is the primary surface water beneficial use category. Mississippi's high dependence on groundwater runs opposite the trend for most of the comparison states and Mississippi withdraws the least amount of groundwater relative to neighboring states. As Mississippi moves forward through economic and community development it is important to recognize the environmental and economic values of water. This research provides a broad perspective for assessing water use in Mississippi as well as understanding the vulnerable aspects of our water resources.

The Mississippi Freshwater Assessment: A New Tool for Supporting Decision Making for Mississippi's Freshwater Resources
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Piazza B.


TNC is in the early phases a project to compile, analyze, and present scientific information to improve conservation and protection of Mississippi's freshwater resources. This comprehensive statewide freshwater assessment is a scientifically sound evaluation of watershed and landscape integrity (i.e., land use and cover, floodplain connectivity, channelization), water quality, surface flow, groundwater trends, and biological health (i.e., trends in species diversity indicators,) of all of the state's watersheds. The data resource and analysis tool will provide a powerful, online mapper with decision-support capability to facilitate the development of freshwater science and conservation objectives and prioritize freshwater conservation statewide. It will be freely available and useful for any stakeholder, including policy- and decision-makers, environmental resource managers, local watershed conservation groups, and the general public, and will allow both technical and lay audiences to evaluate the effects of current and future water use and watershed development proposals. This assessment will provide the capability to draw attention to the status of Mississippi's watersheds, develop agency, NGO, and industry partnerships, and provide quickly accessible facts and figures to support science-based and sound policy outcomes about water. This presentation will describe the framework, components, and capabilities of the assessment system, and will investigate an example of a similar system built for Louisiana. When complete, our Mississippi Freshwater Assessment will integrate with Louisiana's system as well as TNC's Gulf of Mexico Resilience decision support tool (maps.coastalresilience.org) to move toward the ultimate goal of providing a common approach and framework for supporting decision making and management of freshwater and coastal resources across the northern Gulf of Mexico.

Austin's Quadrant: a new framework for assessing water use models
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Czarnecki J.M., Kröger R., Omer A.R.


Although water resources are frequently discussed as an issue of Tragedy of the Commons, this paradigm has well-published shortcomings which make it irrelevant in some situations. A new framework for water use models is proposed where regions are evaluated on two continua, infrastructure and supply. A quadrant is formed wherein regions in quadrant I experience both ample water supply and adequate infrastructure with which to utilize available supply. Regions falling within quadrants II and IV experience a shortage of either supply (II) or infrastructure (IV) but adequate levels of the opposite factor. Regions falling within quadrant III bear the double burden of limited supply and infrastructure. This paper explores case studies within the four quadrants and attempts to answer the questions: (1) What does it take to move from quadrants III or IV to quadrants II or I, and more importantly (2) how do regions in quadrant I not move into quadrant II? Engineered infrastructure must increase concomitantly with governance infrastructure or regions will slide farther down the supply continuum. Education and outreach hold the most promise to shoring up the future of water resources for these regions. Users who make the connection between individual use and its effect on aquifer supply are more likely to engage in conserving behavior and to be more accepting of regulation of use. If adequate education alone is unable to stem overuse, then at least regulation will be supported.

An Assessment of Private Wells Used for Drinking Water in Mississippi and Alabama
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Barrett J., Grammer P.


Most residents of Mississippi and Alabama are served by one of the over 1,700 public water systems in these states. Having access to a public water system provides citizens with safety and quality of water through the regulatory enforcement of the Mississippi State Department of Health-Bureau of Public Water Supply (MSDH) and the Alabama Department of Environmental Management (ADEM). Mississippi and Alabama citizens on private wells do not have the luxury of knowing the quality and/or quantity of their water on a regular basis. Unfortunately, a reliable method for determining the population that depends on a private well for their water supply has not existed since the 1990 census. This presentation will compare currently available methods and present a new methodology for estimating private well usage in Mississippi and Alabama. This novel method uses connections reported to the Safe Drinking Water Information System adjusted to account for non-residential connections, along with census data to generate improved estimates that are quite different from other available sources. This method has been used to generate well usage estimates for all counties in Mississippi and Alabama that can be utilized to better strategize water infrastructure improvements and well monitoring programs.

Enhancing the USGS Streamgaging Network in the Mississippi River Basin: Continuous Water-Quality and Groundwater Data
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Roberts B.A.


The U.S. Geological Survey (USGS), Mississippi Water Science Center, in cooperation with the U.S. Army Corp of Engineers, Vicksburg District, is in the process of enhancing selected streamgages throughout the Mississippi River Basin to include continuous hourly water-quality and groundwater data. In Mississippi, the USGS is installing a ultraviolet nitrate sensor to collect continuous nitrate data, and a water-quality sonde to collect continuous temperature, specific conductance, turbidity, chlorophyll-a, and dissolved organic matter data on the Mississippi River near Vicksburg, Miss., and the Bogue Phalia near Leland, Miss. Both sites will be operated in conjunction with the USGS National Water Quality Assessment Program to understand nitrate dynamics during extreme hydrologic conditions such as baseflow and storms and to provide a more complete data set for future nitrate load calculations.

Quality of water in public supply wells located in the Southeastern Coastal Plain and Coastal Lowlands aquifer systems, Mississippi, 2013
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Welch H.L., Barlow J.R.


Groundwater provides over one-third of the water used for public supply in the United States and nearly half of the water used for public water supply in the southeastern United States. In 2013, the U.S. Geological Survey's National Water Quality Assessment Program began studies to provide nationally consistent water-quality data from principal aquifer systems that account for the majority of withdrawals for public supply throughout the United States. Two of these principal aquifers, the Southeastern Coastal Plain and Coastal Lowlands aquifer systems, were selected for sampling in 2013. These aquifer systems are located in the southeastern part of the United States, and each consists of unconsolidated to semiconsolidated sand, silt and clay deposits that thicken and dip coastward. The Southeastern Coastal Plain aquifer system spans approximately 90,000 sq miles and includes parts of 6 states, and the Coastal Lowlands aquifer system spans approximately 98,000 sq miles and includes parts of 5 states. Public-supply wells were selected for sampling using an equal-area grid approach to ensure a spatially unbiased sampling distribution.

Indirect Regulation of the MRVA Aquifer: Options for the Mississippi Delta
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Massey J.H.


An intensively used resource requires intensive management. The Mississippi River Valley Alluvial aquifer is an intensively used resource whose value will only grow as demand for irrigation continues to rise. Effective regulation is necessary in the management of commonly-held resources, and may be direct or indirect in form. Direct regulation includes actions such as permitting, metering, monitoring of water extractions, and assessment of extraction fees. Indirect regulation seeks to manage a resource without coming in direct contact with it. Educational and certification programs represent indirect forms of regulation. Water-resource management literature suggests that indirect regulation is more effective and practical in situations where large numbers of geographically-diffuse extractors use the resource. This is because the cost of effective direct regulation is often prohibitively expensive. Given that there are more than 18,000 active agricultural groundwater well permits distributed over a 17 county area in the Mississippi Delta, indirect regulation will, by necessity, play an important role in the successful management of the alluvial aquifer. The purpose of this presentation is to discuss options for the indirect regulation of the Mississippi River Valley Alluvial aquifer.

Nutrient Reduction In Mississippi: Partnering For Success
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Bhowal P.


Mississippi is blessed with abundant water resources, and protection of these water resources is essential to ensure sustainability of Mississippi's ecosystems and economies. One of the biggest challenges for Mississippi's surface waters, the Mississippi River and the Gulf of Mexico is the presence of excess nutrients in these waters. The Gulf of Mexico contains a hypoxic zone that is a result of nutrient-rich water from the Mississippi River flowing into the Gulf. Nutrients, in the form of nitrogen and phosphorus, come from a variety of sources including farmlands and lawns where fertilizers are used, wastewater treatment facilities, animal wastes from farms and pasturelands. Accordingly, the issues of nutrient pollution and Gulf Hypoxia have become priorities for Mississippi's Delta, Upland and Coastal regions that contribute significant nutrients loading to the Gulf. Mississippi's approach to reduce nutrient loadings within basins and to the Gulf of Mexico is a highly collaborative, stakeholder supported process centered on development and implementation of comprehensive nutrient reduction strategies for the Delta (December 2009), Coastal (March 2011), and Upland (March 2011) regions of the state. These strategies identified 11 strategic elements to help reduce nutrient loading to Mississippi's surface waters. Over 50 staff from multiple state and federal resource agencies and other organizations in Mississippi have been working together to help develop and implement these comprehensive nutrient reduction strategies. Implementation includes engaging stakeholders, characterizing watersheds, determining status and trends, documenting management programs, establishing quantitative targets, selecting analytical tools, identifying/implementing established and innovative best management practices (BMPs), designing monitoring work, providing incentive and funding, and communicating results. These nutrient reduction strategies are currently being implemented in 10 priority watersheds in the Delta (7), Upland (2), and Coastal (1) regions of the state.

Benefits of On-Farm Water Storage Systems in Porter Bayou Watershed
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Tagert M.L., Paz J.O., Pote J.W., Kirmeyer R.L.


Since the 1970's, groundwater levels in the Mississippi Alluvial Aquifer have decreased as the number of irrigated acres in the Mississippi Delta has increased. Today, there are roughly 18,000 permitted irrigation wells dependent on water from the Mississippi Alluvial Aquifer, with approximately 50,000 new irrigated acres added both in 2011 and 2012. As concern has grown over groundwater declines and increasing fuel costs to run irrigation pumps, farmers have been implementing more irrigation conservation measures, such as on farm water storage (OFWS) systems. These systems began appearing in the Mississippi Delta in 2010 in conjunction with the implementation of the Mississippi River Basin Healthy Watersheds Initiative (MRBI). OFWS systems typically are surrounded by fields that are padded and piped, directing rainfall and runoff to a tailwater recovery ditch, from where it is then pumped into a pond for storage. Water is pumped from the pond and used for irrigation at a later date. These systems offer farmers the dual benefit of providing water for irrigation and also capturing nutrient rich tailwater for on farm reuse. This presentation will give an update on the project, which has monitored water savings and nutrient levels at two OFWS systems, one each at Metcalf Farm and at Pitts Farm, in the Porter Bayou Watershed, Mississippi. Data collection began in February 2012 and is ongoing, with water samples collected for analysis every three weeks throughout the growing season from March-October and every six weeks through the off season. Cumulative readings were also taken on flow meters to measure water use from the storage pond. The ability of these systems to reduce downstream nutrient concentrations has been mixed, with systems performing better when the tailwater recovery ditch is not full and can contain runoff on site. Thus, better management will improve the nutrient reduction potential of these systems. The water savings potential of these systems has been substantial. Metcalf Farm used 42 and 17 million gallons of water from the storage pond in 2012 and 2013, respectively; Pitts Farm used 60 and 56 million gallons of water from the storage pond in 2012 and 2013, respectively. These amounts reflect savings in groundwater that was not pumped from the Mississippi Alluvial Aquifer.

Assessing new BMPS: efficiencies of a Tailwater Recover System and On-farm Storage Reservoir
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Omer A., Kröger R.


The Lower Mississippi Alluvial Valley in Mississippi is economically important due to its highly productive agricultural land. However, producers in this region face two predominant environmental issues that are inherently linked to the agricultural industry. Firstly, intensive agriculture practices which have resulted in increased surface transport of nutrient laden sediments, contributing to eutrophication in receiving waters and to the Gulf of Mexico Hypoxic Zone. Secondly, current water withdrawals from the Mississippi River Valley alluvial aquifer for irrigation during the growing season when precipitation is minimal are not sustainable. These issues threatening environmental resources necessitate best management practices (BMPs) and groundwater conservation. This research investigates BMP systems as water resource conservation methods. Such practices include surface water capture and irrigation re-use systems, referred to as tailwater recovery systems (TWR) and on-farm storage reservoirs (OFS). A single year investigation of two TWRs and one OFS highlighted water holding capacities for irrigation reuse and functionality for nutrient capture as well. Research also included the investigation of the delivery of nutrients and water from a TWR to rice fields during the 2013 growing season, which allowed for the calculation of potential economic savings by a producer pumping surface water rather than ground water. While this research is ongoing, initial investigations indicate that TWRs and OFSs have much promise for water conservation in the Lower Mississippi Alluvial Valley.

Using low-grade weirs as a BMP: Effects on nutrient remediation and microbial denitrification
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Poganski B., Kröger R.


Although the term "anthropogenic influence" often has a negative connotation surrounding it, it encompasses all human influences to the environment, including flood control, restoration, and conservation practices. Interestingly, in addition to land use purposes, water management practices, such as BMPs, can also influence factors affecting denitrification. A study was conducted evaluating the composition of microbial communities involved in key processes of denitrification following physiochemical changes introduced by low-grade weir implementation. Investigations of functional genes involved in denitrification via quantitative polymerase-chain reaction (qPCR) included those encoding for subunits of nitrate reductase (nirK, nirS) and nitrous oxide (nosZ). Understanding how low-grade weirs alter drainage environments in such a way that impacts microbial community structure and function, and subsequent nutrient transformations, which will advance engineering and remediation strategies. Understanding the impacts of low-grade weirs on nutrient reduction capacities will also provide a greater understanding of how to improve nutrient management strategies to reduce Gulf of Mexico hypoxia.

Effects of organic carbon amendments on nitrogen removal in agricultural drainage ditch sediments
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Faust D.R., Kröger R.


Agricultural fertilizer applications have resulted in loading of nitrogen nutrients to agricultural drainage ditches in the Lower Mississippi Alluvial Valley, contributing to the Gulf of Mexico hypoxic zone. Previous studies have observed that nitrogen loading decreases with implementation of best management practices within and in proximity to aquatic ecosystems in agricultural settings. The purpose of this study was to determine effects of organic carbon amendments on nitrogen removal in agricultural drainage ditch water at various lengths of time and carbon-to-nitrogen (C:N) ratios. In one experiment, control, dissolved organic carbon (DOC), and particulate organic carbon (POC) amendment groups were prepared in laboratory microcosms for time treatments of 3, 7, 14, and 28 days with six replicates per treatment. In a second experiment, control, DOC, and POC amendment groups were prepared in microcosms at C:N ratios of 5, 10, 15, and 20 with six replicates per treatment. A permutational multivariate analysis of variance was used to detect statistically significant differences in nitrogen nutrient among treatments (F11,60=19.0, P=0.001 and F8,45=23.2, P<0.001). Mean increases of 3.27 ± 0.52 and 19.2 ± 4.5 mg N L-1 of total nitrogen were observed in overlying water of all treatments of experiments one and two, respectively. However, 60-100% removal of nitrate-nitrogen in overlying water was observed in all treatments with removal occurring in DOC and POC treatments. These results indicate that amendments of organic carbon made to drainage ditch sediments increase nitrate-nitrogen removal, particularly over longer periods of time. Any amendments of DOC increase N removal, regardless of C:N ratio, while amendments of POC at a C:N ratio of five are optimal for N removal. This study provides support for using organic carbon amendments as a best management practice in agricultural drainage ditches.

Distribution and Cycling of Mercury Species in Wetlands and Reservoirs in Northern Mississippi
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Cizdziel J., Brown G.


Methylmercury (MeHg) is a neurotoxin that accumulates in tissues and biomagnifies up the aquatic food chain. Fish consumption advisories have been issued Enid Lake and the Yocona River, a large reservoir and its tributary in north-central Mississippi. This study examined the origin, distribution, and cycling of mercury species in the Yocona River, Enid Lake and associated wetlands. Environmental conditions can have a dramatic impact on the production, transport and fate of Hg species in a given area. Wetlands play a critical role in the cycling of Hg in watersheds and have been shown to be net sources of MeHg to ecosystems. Total-Hg and MeHg were determined seasonally over the course of two years in the inflow and outflow of Enid and Sardis Lakes, in associated wetlands. The Hg species were also measured during storm events (i.e., in runoff from urban, agricultural, and wetland/forest areas). A range of water quality parameters were measured to determine the primary factors controlling the distribution and transport of Hg species in the watershed. The project served as an important step toward building a mass balance for mercury in Enid Lake. Key findings include: - Wetland areas were determined to be hotspots for MeHg in the watershed with relatively high concentrations in water and fish - Levels of Hg in river water were highest at peak flows during storm events. - Forest soil and wetland sediment had higher levels of Hg and organic matter than agriculture soils. - Hg levels were highest in the urban runoff, followed by forest/wetland, and agriculture. - Runoff from highly erodible agricultural areas likely provides the largest input of Hg to Enid Lake by transport of particle-bound-Hg. - MeHg in wetland water was about double that found in lake water, and both spiked during the summer months, with wetlands reaching as high as 1.3 ng/L. - MeHg in the wetland water was negatively correlated with oxidizing reducing potential. - The net flux of T-Hg in Enid Lake was the most negative in the winter due to lowering of lake water levels to accommodate spring rains, and most positive during storm events, suggesting that rain storm events contribute a significant portion of Hg to the lakes. - The net flux of MeHg in Enid Lake was more negative in the summer than fall and spring due to higher methylation and evaporation rates.

Flood Inundation Mapping to Aid Emergency Management Planning in the Cities of Hattiesburg and Petal
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Storm J.


Many cities throughout Mississippi are located on or near major rivers or streams. As a result, residential, commercial, and industrial areas, as well as transportation structures can be at risk when flooding occurs. The cities of Hattiesburg and Petal are located along the Leaf River and have experienced flooding in the past including major events in 1961, 1974, and 1983. The largest recorded flood event occurred on April 15, 1974 and affected approximately 6,000 people and caused damages in excess of $8.3 million (1974 value unadjusted for inflation). The U.S. Geological Survey (USGS), in cooperation with the Cities of Hattiesburg and Petal, Forrest County, Mississippi Emergency Management Agency, Mississippi Department of Homeland Security, and the Emergency Management District, has developed a series of flood inundation maps at 1-foot increments ranging in stage from bank-full (22.0 ft) to approximately the peak of record flood (34.0 ft) for a 6.8 mile reach of the Leaf River through the cities. A one-dimensional steady-flow model was calibrated with the stage/discharge relationship at the USGS stream gaging station 02473000 Leaf River at Hattiesburg, MS (http://waterdata.usgs.gov/ms/nwis/uv/?site_no=02473000&PARAmeter_cd=00065,00060), and flood profile information obtained following the 1974 event. The model results were coupled with land surface elevation data from Light Detection and Ranging (LiDAR) surveys and GIS to produce inundation maps depicting the areal extent of flooding in Hattiesburg and Petal at pre-defined river stages. The inundation maps are available to the public through a web based interactive mapper that allows the user to select the river stage and then display the corresponding inundation map. Estimated water depths are shown by clicking anywhere within the inundated area on the map. Emergency management personnel will be able to use the inundation maps to manage and plan a course of action for future floods by pre-determining affected residences, businesses, municipalities, and roadways at forecasted National Weather Service (NWS) flood levels. Citizens will be able to visually determine what affect there may be to their property or business and take appropriate action ahead of time. The maps are available to the public through the USGS and from the NWS at the following links: http://wim.usgs.gov/FIMI/ http://water.weather.gov/ahps/inundation.php

Quantitative Estimation of Suspended Sediments and Associated Mercury Concentration in Enid Lake Using Remote Sensing Techniques
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Hossain A., Chao X., Cizdziel J., Jia Y.


The streams, lakes, and reservoirs in the Yazoo River Basin provide significant natural and recreational resources in Mississippi. However, since the soils in this region are highly erodible, large amount of sediments are discharged into the water bodies. Sediments are often associated with pollutants, which cause many water bodies in this region to be impaired due to the contaminated sediments. Mercury is one of the widely distributed and persistent pollutants in this environment. Mississippi currently has 11 water bodies under fish consumption advisories for mercury, including Enid Lake. To study the mercury contamination issue in the Enid Lake, the National Center for Computational Hydroscience and Engineering at the University of Mississippi has an on-going research project funded by the Mississippi Water Resources Research Institute and USGS to study the transport, fate, and risk of mercury in Enid Lake. As one of the tasks of this project the potential of the remote sensing techniques were explored to estimate the mercury concentration associated with suspended sediments in Enid Lake. Suspended sediment concentration has been estimated and mapped successfully using remote sensing for the last three decades. Different approaches and algorithms had been developed over time for SSC estimation using optical satellite data. Several studies had success in estimating total suspended sediments (TSS) using simple linear regression techniques involving the Moderate-resolution Imaging Spectroradiometer (MODIS) visible and near infra red (VNIR) data and in situ measurements. Similar approach was used in this study to estimate TSS and associated mercury concentration in Enid Lake, MS. The correlation coefficients of the regression equations were obtained using in situ measurements of TSS and mercury from two field campaigns, and near-real time reflectance values of the VNIR bands of MODIS imagery. Preliminary results indicate that these regression equations can be used for quantitative estimation of TSS and associated mercury in Enid Lake with reasonable accuracy

An Integrated Watershed Approach to Water Sanitation and Hygiene priorities for Lake Chivero, Zimbabwe
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Buka H., Linhoss A., Pote J.


This paper describes an integrated watershed approach to water sanitation and hygiene for a water supply reservoir near Harare, Zimbabwe`s capital city. From the construction of the lake to the present, considerable difficulties have been experienced in water quality and water treatment. Discharges from urban and rural agriculture, sewage treatment works and industries have caused severe stresses on the lake's water quality. To combat eutrophication in the mid-1970s, a Hydrobiology Research Unit was established to facilitate pollution research and a biological nutrient removal sewage treatment plant was also installed. This was successful for a decade but afterwards water quality started to deteriorate due to increases in population. The original sewage treatment plants were designed to handle 18 million liters of human waste a day for a population of about 500,000 people but now the estimated population has exceeded 1.4 million people therefore overloading the sewage works. Continued deposition of sewage effluents has contributed to the spread of aquatic weeds such as water hyacinth (Eichhornia crassipes), blue-green algae (Anabaenopsis sp) and spaghetti weed (Hydrocotyle ranunculoides). The weeds strive under a constant supply of nitrogen and phosphorus as they are the major nutrients in the Lake. The area around the lake has been designated as a wildlife sanctuary, which offers the potential for managing water quality better. In 1997 there were recorded fish kills especially the Green headed Tilapia due to low levels of oxygen. A total of 11,735 cholera cases were recorded as of December 2008 due to poor sanitation and water shortages. For these reasons the objective of this review is to assess the integrated impacts of water quality on the environment and sanitation throughout the lake, watershed, and water supply service area.

Regional Rainfall Frequency Analysis and drought reduction in the Tombigbee River Basin
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Ramirez-Avila J.J., McAnally W.H., Tagert M.L., Ortega-Achury S.L.


A regional frequency analysis was conducted for precipitation to bring more detailed information about the amount and distribution of rainfall over the Tombigbee River Basin to promote efficient water resources management in the study area. In addition, the results of the regional frequency analysis were combined with climatological drought reduction information to determine the probability that a cumulative precipitation depth needed to end a drought will be equaled or exceeded at least once in a specific season in the Tombigbee River Basin. A total of 28 precipitation gages in eastern and northeastern Mississippi and western Alabama were included in the study representing 1,352 station years of record. A regional analysis methodology was utilized, and the Tombigbee River Basin was considered a homogeneous region to increase the dataset and improve the reliability of precipitation-frequency estimates. The International Center for Integrated Water Resources (ICIWaRM) Regional Analysis of Frequency Tool (ICI-RAFT) was used to develop the regional frequency analysis. The software involves the application of the L-moments to characterize the variability, skewness and kurtosis of the data, determine heterogeneity in the region, and assist in the identification of appropriate regional probability distribution(s). Verification of results indicated that the selected frequency distributions provide reliable exceedance values for precipitation. Results also showed that spring would be the season with a more probable chance of recovery from a moderate or severe drought in the Tombigbee River Basin.

Interdisciplinary Assessment of Mercury Transport, Fate and Risk in Enid Lake, Mississippi
Final Project Report

Year: 2014 Authors: Chao X., Cizdziel J.V., Willett K., Hossain A.K.


Enid Lake is one of the important large recreation lakes in Mississippi, and the mercury level is relatively high compared with other large lakes. This research brought together a team of scientists that with their expertise in analytical chemistry, remote sensing technology, hydraulic modeling and risk assessment to study the transport, fate and risks of mercury in Enid Lake. Two field measurements were conducted in spring and fall to measure the flow, sediment and mercury in Enid Lake. The remote sensing technology was applied to analyze the concentration distributions of sediment and mercury in the whole lake, and the results are generally in good agreement with measured data. A numerical model was developed to simulate the flow, sediment, and mercury in the lake, and the interaction between the mercury and sediment was taken into accounted. Risk assessment was conducted to analyze the potential risk of mercury both in the environment and human fish consumption. The research results help us understand the transport mechanisms of sediment and mercury in large lakes, and provide useful information for decision makers to evaluate established TMDLs and fish consumption advisories.

The Red Creek Consolidated Mitigation Bank and the Challenges of Stream Restoration in Gulf Coastal Plain Soils and Weather
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Maurer B.


Since the Mobile and Vicksburg districts of the Corps began regulating impacts to streams, the Mississippi Department of Transportation has been proactive in acquiring advance credits for future impacts in several watersheds. One such project is the Red Creek Consolidated Mitigation Bank, located in coastal Jackson County and established in partnership with The Nature Conservancy. Approved in 2011, this wetland and stream bank is providing credits on wet pine flats, bayhead and bottomland hardwood forest, and 3,345 linear feet of stream restoration primarily on two reaches of a tributary to Red Creek. The site is part of an ecologically-significant conservation area in the Pascagoula River watershed. The two restoration reaches have distinctive features; a Priority 2 Restoration was completed on steep and highly entrenched section of the upper stream to arrest severe headcutting. In the second reach, Priority 1 stream relocation was completed in a low-gradient bottomland forest to prevent active downcutting. Completed in the spring of 2012, the stream restoration work was subject to several substantial rain storms (including Hurricane Isaac, which dropped 15-20 inches on the site) before soils had settled and vegetation was fully established. In addition, unforeseen seepage areas developed on some of the steeper slopes causing slumping in the toe areas. Significant damage from storms in these seepage areas and later universally throughout much of the project forced a re-evaluation of the design before repairs were completed. This presentation will discuss and contrast the two restoration reaches, including the challenges of choosing Best Management Practices (BMPs)for stream restoration, and establishing vegetation in erodible, relatively low-nutrient soils and unfavorable weather conditions (hot and dry with periodic intense rainfall). Finally, we will evaluate the damage and repairs to restoration reaches, and how the untimely storms quickly taught us what worked best and what needed improvement.

Groundwater Depletion in the Mississippi Delta as Observed by the Gravity Recovery and Climate Experiment (GRACE) Satellite System
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Hossain A.


The Gravity Recovery and Climate Experiment (GRACE), launched in early 2002, is a satellite mission jointly managed by the US National Aeronautics and Space Administration (NASA) and the German Aerospace Center (DLR). Its goal is to map Earth's gravity field with high precision, approximately on a monthly basis. Global representations of Earth's gravity field are produced based on a K-band microwave system, which measures the distance (loosely controlled at about 220 km) between two identical satellites nearly continuously as they revolve in a tandem, near polar orbit, at an initial 485 km altitude. The gravitational effects of changes in atmospheric surface pressure and ocean bottom pressure are removed using numerical model analyses, such that the remaining variability can be attributed primarily to the redistribution of terrestrial water storage, thus provide measurements of column integrated terrestrial water storage (TWS) for the entire globe. Several recent studies clearly demonstrated that GRACE-derived estimates of variations of total water storage (all of the snow, ice, surface water, soil water and groundwater in a region), when combined with auxiliary hydrological datasets, can provide groundwater storage change estimates of sufficient accuracy to benefit water management. This paper summarizes the recent studies that conducted to investigate the groundwater depletion in the Mississippi Delta using GRACE data. This paper also presents the results obtained from the analysis of last ten years monthly GRACE Level 3 data for the Mississippi Delta areas.

Water Depth In An Oxbow Lake-Wetland And Its Influence On Soil Chemistry, Cypress Tree Growth, And Groundwater Recharge
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Lahiri C., Davidson G.R., Threlkeld S.T.


Sky Lake, MS, is an oxbow lake-wetland that was once part of the ancestral Ohio-Mississippi River system. It hosts some of the largest and oldest cypress trees in the state, with several trees exceeding 40 ft in circumference. An elevated boardwalk recently built into the heart of the wetland now allows unique access to the public and has provided a platform for mounting experimental equipment to monitor several environmental parameters pertinent to managing wetlands and water resources. An ongoing study along the boardwalk is currently monitoring changes in water level, water and soil chemistry (pH, Eh, DO, conductivity, temperature), and atmospheric parameters (precipitation, temperature, relative humidity), and relating the data to tree growth (sap flow rates, trunk expansion) and to changes in groundwater level in a monitoring well located inside the meander loop. Preliminary data indicate that both the flow and chemistry of water within the root zone is highly variable over short distances, likely caused by physical heterogeneity created by fallen and buried tree limbs in various stages of decomposition. Substantial changes in soil zone Eh, an indicator of the redox potential that can influence nutrient uptake by plant roots, were observed over time with no significant correlation between measurement locations. This means that single measurements of soil chemistry at point locations in this wetland environment are not necessarily representative of the conditions for the system as a whole. Measurements at multiple locations are required to adequately assess the chemical conditions that contribute to the health of wetland flora. Groundwater levels measured in the monitoring well rose and fell over a several month period corresponding to high and low water levels in the wetland, respectively, suggesting a possible surface-groundwater connection. Digital cameras set up with dendrometer bands are allowing collection of daily changes in the circumference of four different trees that will allow correlation with sap flow and the monitored environmental variables.

Delineation of Watersheds in Northwestern Mississippi to the Sub-Watershed Level
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Rose C.E.


In 2009, river systems in Mississippi were delineated to the watershed level, and most were delineated to the subwatershed level. One of the exceptions was the northwestern part of Mississippi in the lower part of the Yazoo River Basin (locally referred to as the "Delta") where only watershed-level delineations were completed. Watersheds and sub-watersheds previously delineated in Mississippi were based on elevation change and water body locations as observed from topographic maps, digital elevation models, and aerial photographs. Previous attempts to delineate watersheds in the Mississippi Delta region to the sub-watershed boundaries were problematic due to the following issues: topographically-uniform, low relief land elevations (less than 100 feet of rise in land-surface elevation from Vicksburg to Memphis); land management practices employed by land owners and growers who frequently change drainage patterns; and insufficient scale of available elevation to allow delineation of subtle topographic features. Therefore, the Mississippi Delta region was not delineated to the sub-watershed level until more precise digital elevation tools were available for use. Delineation of watershed boundaries and designation of watershed numbering and naming is an important first step for resource managers that are concerned with ecosystem and water body health and remediation of point and non-point source pollution. Previous scientific studies have implicated the Delta region as a contributor to the hypoxic zone in the Gulf of Mexico, and a large percentage of Delta waters are listed as impaired on the section 303(d) List of Impaired Waters. For Delta streams, ecosystem health and mitigation of nonpoint source pollution is a primary concern for resource managers, and delineation of watersheds in this region is a critical and necessary step for future planning and mitigation activities. Since the publication of the Mississippi Watershed Boundary Dataset in 2009, the entire Yazoo River Basin (including the Mississippi Delta region) has been mapped using Light Detection and Ranging (LiDAR) technology (funded by the U.S. Army Corps of Engineers, Vicksburg District), which has a root mean square error vertical land surface bare-earth accuracy of 9 centimeters. With the availability of LiDAR data, it is now more reasonable to delineate the Mississippi Delta region to the sub-watershed level. The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, has completed the delineation of river systems in the Mississippi Delta region to the subwatershed level.

Pathogen Indicator Monitoring in the Ross Barnett Reservoir
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Capps P., Hicks M., Surbeck C.Q.


Man-made reservoirs are often used for both water supply and recreation. The US Environmental Protection Agency's (EPA) recent National Lakes Assessment survey includes water quality concerns for beneficial uses of such man-made reservoirs. The EPA ranks the Ross Barnett Reservoir watershed as the most important in the state of Mississippi and has selected it as a Priority Watershed. The Ross Barnett Reservoir, a 33,000-acre lake, provides drinking water to the city of Jackson, MS, and forty-eight surrounding communities. Further, an estimated 2.5 million people visit the reservoir each year for recreational purposes, including boating, fishing, water-skiing, and swimming. Substantial residential and commercial developments in Madison and Rankin counties along the 105 miles of reservoir shoreline have the potential to affect water quality in the reservoir. Due to the reservoir's important role as a water-supply source, the protection of the water quality in the reservoir is crucial for human health. A collaborative investigation is underway by the University of Mississippi, the U.S. Geological Survey, and the Mississippi Department of Environmental Quality, to assess pathogen indicator concentrations in the Ross Barnett Reservoir. Sources of the pathogens may include stormwater runoff, failing septic systems, lake-bottom sediments, and humans in direct contact with the water. Data for pathogen indicators and other water-quality parameters such as water temperature, pH, dissolved oxygen, conductivity, nitrate, phosphate, and solar strength, were collected at two recreational sites at the reservoir twice a week for 23 weeks through the spring and summer of 2013. Average concentrations for all E. coli, enterococci, and fecal coliform were 264 cfu/100mL, 175 cfu/100mL, and 298 cfu/100mL, and standard deviations for each were 654 cfu/100mL, 249 cfu/100mL, and 952 cfu/100mL, respectively. The concentrations of pathogen indicators and nutrients, and values of physical parameters will be statistically analyzed to provide insight about contamination sources. A review of past monitoring efforts in other related fresh-water lakes will also be reported.

Water quality modeling in the Ross Barnett Reservoir
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Jackson G.


This study presentation investigates the utilization and economic feasibility of hydrodynamic models as tools for assessing factors impacting water quality in the Ross Barnett Reservoir and the Pearl River for nutrient TMDL development. The primary focus is the development steps necessary to create a hydrodynamic model that provides transport information to subsequent application of a water quality model (WASP). Environmental Fluid Dynamics Code (EFDC) is a complex, dynamic, multi-dimensional computer model used to simulate hydrology in water bodies. The hydrodynamic model output feeds directly into the WASP water quality simulation. The secondary focus is on data acquisition and EFDC model manipulation methods for completing the hydrodynamic modeling. Monitoring was completed to create modern bathymetry of Ross Barnett Reservoir to provide accurate model cell grid representation. Temperature and dissolved oxygen profile monitoring were gathered to provide data for model output comparison. The EFDC model successfully predicted lake stratification and subsequent mixing based on changes in observed meteorological conditions. Finally, the model development costs and level of difficulty must be justified to consider broad use of this model development combination for state water quality agencies. EFDC / WASP model development tools that will reduce the development costs are in production, and should improve the usefulness of the EFDC / WASP model combination in the future.

Climate Variability Impacts on Crop and Sediment Yields
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Parajuli P.B., Jayakody P., Sassenrath G.


This study evaluated future climate variability impact on stream flow, crop and sediment yields under three different tillage systems in the Big Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) was applied to the BSRW using observed stream flow and crop yields data. The model was successfully calibrated and validated and future climate scenarios were simulated. Results showed that there is no significant difference (p > 0.05) between average corn and soybean yields under simulated tillage systems in the BSRW. However, results determined a significant difference on sediment yields from three simulated tillage systems (p values of 0.002 for corn, and 0.003 for soybean). The model simulated results showed that future average maximum temperature may increase and experience a longer summer periods with frequent extreme rainfall events but similar monthly precipitation patterns.

A STELLA model for estimating phosphorus removal from wastewater in a vertical-flow constructed wetland system
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Ouyang Y.


Elevated phosphorus (P) in surface waters can cause eutrophication of aquatic ecosystems and can impair water for drinking, industry, agriculture, and recreation. Vertical flow constructed wetland (VFCW) can purify P contaminated wastewaters before they discharge into streams and rivers. The goal of this study is to develop a model for predicting the fate, transport, and removal of P from wastewaters in a VFCW using the commercial available STELLA (Structural Thinking, Experiential Learning Laboratory with Animation) software. The VFCW used in this study consists of soil and plant species with variably saturation conditions such as wetting (ponding) and drying (draining) cycles. The water movement through the soil, xylem, and surrounding atmosphere in the VFCW system is calculated using water potential theory, whereas the fate and transport mechanisms of P used in this model include: (1) application of wastewater (containing P) to the VFCW; (2) adsorption of P in the soil; (3) uptake of P by plant roots, (4) mineralization of organic P; and (5) leaching of soluble P. Additionally, the surficial processes such as rainfall and evapotranspiration are included in the model. The resulted model is calibrated and validated with experimental data prior to its applications. A simulation scenario is then performed to estimate P removal from a domestic wastewater in the VFCW system under varying hydraulic retention times. Simulation results will be presented and discussed.

Quantification of Harmful Algal Blooms (HABs) in the Grand Bay in Jackson County, MS
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Dampier J., Dash P., Begonia M.F.


Harmful Algal Blooms (HABs) are caused by species of tiny plants, phytoplankton. HABs may cause harm through the production of potent chemical toxins or by their accumulated biomass. Impacts include massive fish kills, loss of sales revenue primarily from fisheries and tourism, loss of commercially valuable and culturally vital shellfish resources, illness and death in populations of protected marine species, and threats to human health. Among the many HAB impacts in the northern Gulf of Mexico, those due to coastal blooms of the diatoms genus Pseudo-nitzschia with its associated toxin domoic acid, and the dinoflagellates of the genus Karenia with its associated toxin brevetoxin are of particular concern. This work (a field, laboratory and satellite remote sensing research) focused on quantifying HABs in the Grand Bay. It encompasses the collection of field data which is analyzed in the laboratory for pigments, suspended sediments, dissolved materials, and toxins as well as a satellite remote sensing component focused on developing techniques for mapping HABs from space. Recently, a procedure was developed to estimate cyanobacterial concentrations by quantifying chlorophyll a and the primary cyanobacterial pigment phycocyanin using OCM satellite data. This required the development of an atmospheric correction and vicarious calibration methodology for satellite data in inland and coastal waters. It has been tested to work for data from several satellite sensors such as OCM, SeaWiFS, MODIS, MERIS and QuickBird. This research is focused on use of satellite sensors, NPP VIIRS and MODIS AQUA, and the developed techniques to quantify HABs in the Grand Bay. In addition to algal toxins, the toxicity of environmental pollutants (i.e., heavy metals such as Pb, Cd, etc.) in the water was investigated and the mutual relationships between the heavy metals and HABs will be examined. This research will enhance the current state of knowledge on detection and mapping of the HABs in the Grand Bay and thus support state and coastal community efforts to manage fisheries in the region.

Groundwater Level Forecasting in Sunflower County, Mississippi using Artificial Neural Networks
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Guzm S., Paz J.O., Tagert M.L.


The Mississippi Delta Region is one of the most important in the United States given the high productivity levels of crops such as corn, cotton, rice, and soybean. Most of these crops require supplemental irrigation to sustain yield and to reduce the impacts of extended periods of dryness during the growing season. Due to the expansion of croplands , the annual volume of groundwater withdrawals have increased dramatically over the past two decades, exceeding aquifer recharge and generating an important reduction in the aquifer levels. In this study, we present the preliminary groundwater level simulation results for a well in Sunflower County that is within the Mississippi River Valley Shallow Alluvial (MRVA) aquifer. The performance of two different artificial neural networks (ANN) for groundwater level forecasting was evaluated in order to identify an optimal architecture that can simulate decreasing trends of the groundwater level in summer season. Two algorithms, Levenberg-Marquardt and Bayesian Regularization, were evaluated in order to obtain a model that shows better results in the simulation of changes in groundwater level and provide acceptable predictions up to 3 months ahead. The ANN predictive performance was assessed based on the comparison between Root Mean Square Error (RMSE) for each algorithm. Neural networks learn and recognize patterns in the nonlinear temporal data through mathematical analysis and computational architecture inspired by how the human brain works given a set of examples. This methodology is a tool to predict in a short period of time, groundwater levels at specific control points that would be used in an optimized regional plan to manage water withdrawals, and help farmers and water managers decide how to implement plan control procedures and conservation practices.

Evaluating the impacts of crop rotations on groundwater recharge and water table depth in the Mississippi Delta
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Dakhlalla A.O., Parajuli P.B.


The Mississippi River Valley Alluvial Aquifer (MRVA), which underlies the Big Sunflower River Watershed (BSRW), is the most heavily used aquifer in Mississippi. Because the MRVA is primarily used for irrigating crops such as corn, cotton, soybean, and rice, the water levels have been declining rapidly over the past few decades. Each crop rotation practice demands certain irrigation amounts and applications, which in turn can affect the hydrogeology of the aquifer. The objective of this study is to assess the impacts of crop rotation practices on groundwater recharge rates and water table depths in the BSRW using the Soil and Water Assessment Tool (SWAT) model. The SWAT model was hydrologically calibrated for monthly streamflow using observed streamflow data from 3 USGS gage stations (Merigold, Sunflower, and Leland). Because this study focuses on groundwater processes, the model was also calibrated for water table depths at several ground water wells throughout the BSRW. The observed water table depths used to calibrate the model were provided by the Yazoo Management District (YMD). The model was evaluated based on the coefficient of determination, Nash-Sutcliffe Efficiency, and root mean square error statistics. The crop rotation scenarios that will be employed in this study are corn after soybean, soybean after rice, and continuous soybean. This study will provide some insight into which crop rotation practices cause the most fluctuations on groundwater recharge and water table depths.

Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, MS To The Underlying Alluvial Aquifer
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Patton A.C., Davidson G.R., Rigby J.R., Barlow J.


Long-term groundwater level and river stage measurements at a USGS coupled groundwater stream-gaging station located on the Sunflower River at Sunflower, MS show an apparent stage-threshold for infiltration to the underlying alluvial aquifer. This site is located near the center of a large regional cone of depression in the Mississippi River Valley alluvial aquifer and therefore provides insight into the effects of groundwater declines on streamflow in the Big Sunflower River. Groundwater levels respond to changes in river stage only when river stage exceeds 34 m msl (mean sea level). The purpose of this research was to identify the responsible mechanism. Two hypotheses were considered: (1) scour of infiltration-limiting fine-grained bottom sediments during high flow rate events at higher stage, and (2) lateral infiltration at high stage into more permeable coarser grained sedimentary layers intersecting the stream channel at higher elevation.

Empirical evidence of recharge in the Mississippi Alluvial Aquifer
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Johnson D.R., Barlow J.


Multiple groundwater models have been constructed to model the alluvial aquifer. These models differ significantly in the allocation of water for recharge. This paper will examine the potential sources of recharge and estimate their magnitudes. Other literature will be used to validate the assumptions presented in this paper.

National Weather Service Flood Surveys & Post-Event Analysis of Hurricane Isaac
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Lincoln W.S.


After the substantial impact to the United States East Coast from Hurricane Sandy, Hurricane Isaac may become the forgotten hurricane of 2012. With its above average size and slow forward motion, Isaac produced higher storm surge than typically seen by a storm of its wind category, and also dropped notably heavy rainfall across portions of southeast Louisiana and south Mississippi. Over a four day period from August 28th to August 31st, rainfall totals ranged from 10-15 inches across most of the area, with a few areas seeing more than 20 inches. This significant rainfall caused flooding of numerous rivers in the forecast area of the National Weather Service (NWS) Lower Mississippi River Forecast Center, especially areas within the county warning area of the New Orleans/Baton Rouge Weather Forecast Office. Because of the rare nature of the event, a team composed of NWS staff from multiple offices was assembled to record the impacts, survey flood crests when necessary, and discuss the event with local residents. Post-event flood surveys were conducted over a number of days in early September, 2012, particularly across the Wolf, Tchoutacabouffa, Biloxi, and Escatawpa River watersheds in Mississippi and the Tangipahoa River watershed in Louisiana. A vast amount of observations, anecdotal data, and recommendations were collected by the survey teams and summarized in a report for the River Forecast Center and the Weather Forecast Office. Flooding of numerous locations was of a magnitude seen only on very rare occasions and may have been the worst flooding yet-experienced by numerous long term residents. Luckily, due to the sparse population density in most of the river floodplain areas, impacts were not as severe as would typically be expected. Findings from the post-event flood surveys and analysis of data from numerous sources will be presented to further our understanding of Isaac's hydrologic impact.

The Role of Long-term Monitoring In Understanding Phosphate Spills Into A National Estuarine Research Reserve
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Cressman K., Woodrey M., Ruple D.


Grand Bay National Estuarine Research Reserve (GBNERR) is an 18,400-acre protected area in southeastern Jackson County, MS. The GBNERR, along with 27 other Reserves, collects long-term environmental data, including water quality, weather and nutrient parameters, following accepted national protocols as part of a System-Wide Monitoring Program (SWMP). In 2005, a phosphate facility on GBNERR's western border released wastewater into Bangs Lake. Data from SWMP were used to help determine the timing and duration of the event. The pH measured by a data logger deployed at the Bangs Lake water quality station dropped to 3.7. Orthophosphate, tested monthly in the water column and usually below the detection limit of 0.01 mg/L, spiked to over 4 mg/L: more than 400 times higher than normal. PO4 concentrations returned to baseline levels after Hurricane Katrina and remained below 0.01 mg/L until September 2012, when Hurricane Isaac led to another release into Bangs Lake. Routine nutrient sampling three weeks after Isaac found phosphate levels over 1 mg/L in Bangs Lake. Phosphate was also high at further distances from the plant. As of December 2013, other stations' water column phosphate concentrations had returned to normal, but phosphate in Bangs Lake remained higher than historical levels. Research by collaborators at nearby institutions has helped fill in details of the magnitude and spatial patterns of the 2012 spill. This work, combined with the long-term context of SWMP data, led to the formation of a Phosphate Working Group, which will continue to explore the ecological effects of this long-term addition of phosphorus to Bangs Lake.

Investigating the Water Quality of Four Large Mississippi Lakes and Grand Bay, MS-AL Gulfcoast
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Dash P., Ikenga J.O., Pinckney J.L.


Harmful Algal Blooms (HABs), harmful microorganisms, and toxic metals represent three main water quality deteriorating agents in the water-bodies. The objectives of this research were to take a systems level approach to investigate the water quality of four large Mississippi freshwater lakes including lakes Sardis, Enid, Grenada and Ross Barnett Reservoir and the Grand Bay in Mississippi Alabama gulf coast. Ten field campaigns were undertaken to the freshwater lakes and six sampling trips were organized to the Grand Bay to collect water samples, to measure the physical parameters including temperature, salinity, dissolved oxygen and pH, to measure remote sensing reflectance and backscattering at twelve discrete sites in each of the water bodies. The water samples were collected for high performance liquid chromatography (HPLC) photopigments, colored dissolved organic matter (CDOM), suspended particulate matter (SPM), phycotoxins, nutrients, absorption, bacterial counts, toxic metals, and microscopy analyses. In all these water-bodies, organic SPM surpassed its inorganic counterpart, which indicates that organics have a bigger share in the water quality deterioration in these systems. The photo-pigments derived relative abundances of major algal groups suggested the abundance of cyanobacteria, diatoms and dinoflagellates in all these systems. An investigation of the species composition will reveal the detail community structure. Phycotoxins and several types of bacteria and toxic metals were found in all the water bodies. The observation of these water quality issues warrants continuous operational monitoring of the water quality, investigation of fate and transport of pollutants, and implementation of best management practices for all these water-bodies.

Flow Characteristics of Selected River Basins in Mississippi
Proceedings of the 43rd Mississippi Water Resources Conference

Year: 2014 Authors: Runner M.


The U.S. Geological Survey has been collecting stage and flow data at select locations in Mississippi for more than 100 years. The first data collection station was built on the Tombigbee River at Columbus in 1895. Currently, continuous flow data are collected at more than 70 locations and instantaneous peak flow data at an additional 95. Stage and flow data have many uses and serve a variety of purposes filling a valuable need for both governmental agencies, academic institutions, and the general public at large.

There are many benefits to a stable streamgaging program including resource management, flood operations of structures, and flood forecasting. Most of these benefits are derived from access to current flow data, but there are benefits from long-term data sets that are not as readily apparent. One of these is the ability to use these data to detect trends in flow characteristics over time.

This report presents statistical summaries for data sets of select gages near the mouth of major river basins in Mississippi. Data for the Tombigbee, Chickasawhay, Leaf, Pascagoula, Yazoo, Big Black, and other select rivers are presented.

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