GRI RESEARCH

Hydrometeorology
Under this category, the focus is on topics such as the impacts and evaluation of severe weather and hurricanes and visualization tools created by GRI researchers to streamline important information and data.





Advection of Karenia Brevis Blooms from the FL Panhandle towards the MS Bight and Sound
Harmful Algal Blooms (HABs) of Karenia brevis have been documented along coastal waters of every state bordering the Gulf of Mexico (GoM). Some Gulf Coast locations, such as Florida and Texas, suffer from recurrent intense and spatially large blooms, while others such as Mississippi seem to rarely observe them. The main objective of this work is to understand the dynamics that led to the K. brevis bloom in Mississippi coastal waters in fall 2015. Blooms of K. brevis from the Florida Panhandle region are often advected westward towards the Mississippi-Alabama coast; however there is interannual variability in their presence and intensity in Mississippi coastal waters. The 2015 K. brevis bloom was compared to the 2007 Florida Panhandle K. brevis bloom, which showed a westward advection pattern, but did not intensify along the Mississippi coast. Cell counts and flow cytometry were obtained from the Mississippi Department of Marine Resources, Alabama Department of Public Health, Florida Fish and Wildlife Conservation Commission and The University of Southern Mississippi. Ocean color satellite imagery from the Moderate Resolution Imaging Spectroradiometer onboard the Aqua satellite was used to detect and delineate the blooms in 2007 and 2015.
Abstract and Document Site





AmoebaNet- Testing Advanced Network Capabilities Using GeoFish and OceanNOMADS
This project supports the development of NOAA's NMFS/AFSC. It will use advanced networks to link two existing resources for modeling- the OceanNOMADS server and GeoFish and to test the use of a centralized data store with a local application for advanced modeling and interaction.
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An Updated Synoptic Climatology of Lake Erie and Lake Ontario Heavy Lake-Effect Snow Events
Lake-effect snow (LES) storms pose numerous hazards, including extreme snowfall and blizzard conditions, and insight into the large-scale precursor conditions associated with LES can aid local forecasters and potentially allow risks to be mitigated. In this study, a synoptic climatology of severe LES events over Lakes Erie and Ontario was created using an updated methodology based on previous studies with similar research objectives. Principal component analysis (PCA) coupled with cluster analysis (CA) was performed on a case set of LES events from a study domain encompassing both lakes, grouping LES events with similar spatial characteristics into the primary composite structures for LES. Synoptic scale composites were constructed for each cluster using the North American Regional Reanalysis (NARR). Additionally, one case from each cluster was simulated using the Weather Research and Forecast (WRF) model to analyze mesoscale conditions associated with each of the clusters. Three synoptic setups were identified that consisted of discrepancies, mostly in the surface fields, from a common pattern previously identified as being conducive to LES, which features a dipole and upper-level low pressure anomaly located near the Hudson Bay. Mesoscale conditions associated with each composite support differing LES impacts constrained to individual lakes or a combination of both.
Abstract Research Document





CONCORDE Meteorological Analysis (CMA) Data Guide
CONCORDE is the CONsortium for oil spill exposure pathways in COastal River-Dominated Ecosystems (CONCORDE), and is an interdisciplinary research program funded by the Gulf of Mexico Research Initiative (GoMRI) to conduct scientific studies of the impacts of oil, dispersed oil and dispersant on the Gulf
Abstract Document Oceanography Article Discuses CMA





Cost Effective BMPs for Resilient Communities
This project developed a tool that will enable the development industry to design and build more resilient and sustainable communities through the inclusion of BMPs (Best Management Practices) in new commercial and residential construction.
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Development of a Northern Gulf of Mexico Operational Forecast System
The NOAA National Ocean Service's Physical Oceanographic Real-Time Systems (PORTS) along the northern coast of the Gulf of Mexico will provide real-time oceanographic data to promote safe and efficient navigation. The Northern Gulf Institute, through Mississippi State University, will manage and coordinate this Operational Forecast System (OFS) University of Massachusetts-Dartmouth project activity in the development of a model to support the PORTS. A global or basin-scale model will provide boundary conditions to a proposed northern Gulf of Mexico Shelf domain model.
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Development of a Water Budget for Tail-water Recovery Systems
Unsustainable groundwater use for agricultural irrigation has led to declining aquifer levels across the United States, necessitating implementation of water conservation practices. One conservation practice being implemented throughout the lower Mississippi River alluvial valley (LMAV) that collects and stores surface water for irrigation is a tailwater recovery (TWR) system. Accordingly, the overall objective of this study was to develop a water budget for TWR systems. Eight TWR systems were continuously monitored for water depth, allowing rates of water gain and loss to be quantified. Volumes of water movement were calculated based on change in water depth and system dimensions. Using water budgets derived from TWR systems the water volume was calculated and found to be gaining, except during months of irrigation. Extrapolating the water budget to all TWR systems shows a total offset of 15% of the annual groundwater deficit. Tailwater recovery system efficiencies show designs may be altered to improve the water savings and use of these systems.
Journal of Irrigation and Drainage OnlineSite ASCE Online SIte





Dissolved organic matter and trace element variability in a blackwater-fed bay following precipitation
Highlights Dissolved organic matter compositions were used for source-tracking trace metals. Flux of As, Cu, U, PO4, and NO3 correlated with protein-like and soil-derived DOM. The trace element and DOM mobility was controlled by precipitation and discharge. Multivariate statistics revealed anthropogenic sources for the trace metals. Abstract Dissolved organic matter (DOM) often forms complexes with trace metals. The main objective of this study was to identify the sources of trace elements to a coastal bay that is fed by two blackwater rivers using DOM compositions. Surface water samples from twelve sites in Weeks Bay, Alabama were collected during four field trips and a bottom sediment sample was collected during one of the trips. Spectroscopic measurements in tandem with parallel factor analysis and multivariate statistics were used to derive DOM compositions and inductively coupled plasma mass spectrometry was used for determining trace metal concentrations. DOM chemistry and trace element concentrations together with precipitation and discharge, watershed land use and land cover data, and physicochemical parameters were used to determine the source of trace elements in the adjoining areas of the watershed to the bay and finally settling into the bay sediments.
Science Direct





Dissolved Organic Matter and Trace Element Variability in a Blackwater-fed Bay Following Precipitation
Dissolved organic matter (DOM) often forms complexes with trace metals. The main objective of this study was to identify the sources of trace elements to a coastal bay that is fed by two blackwater rivers using DOM compositions. Surface water samples from twelve sites in Weeks Bay, Alabama were collected during four field trips and a bottom sediment sample was collected during one of the trips. Spectroscopic measurements in tandem with parallel factor analysis and multivariate statistics were used to derive DOM compositions and inductively coupled plasma mass spectrometry was used for determining trace metal concentrations. DOM chemistry and trace element concentrations together with precipitation and discharge, watershed land use and land cover data, and physicochemical parameters were used to determine the source of trace elements in the adjoining areas of the watershed to the bay and finally settling into the bay sediments.
Abstract Document Site





Effect of Photo-biodegradation and Biodegradation on the Biogeochemical Cycling of Dissolved Organic Matter across Diverse Surface Water Bodies
The objective of this research was to quantify the temporal variation of dissolved organic matter (DOM) in five distinct waterbodies in watersheds with diverse types of land use and land cover in the presence and absence of sunlight. The water bodies were an agricultural pond, a lake in a forested watershed, a man-made reservoir, an estuary, and a bay. Two sets of samples were prepared by dispensing unfiltered samples into filtered samples in 1:10 ratio (V/V). The first set was exposed to sunlight (10
Abstract and Research





Effects of Rainfall, Geometrical and Geomorphological Variables on Vulnerability of the Lower Mississippi River Levee System to Slump Slides
This study investigated the importance of rainfall and various geomorphological and geometrical factors to the vulnerability of earthen levees to slump slides. The study was performed using a database including 34 slump slides that occurred in the lower Mississippi River levee system from 2008 to 2009. The impact of rainfall within the six months prior to slide occurrence was studied for 23 slides for which an accurate occurrence date was available. Several variables were used to develop a logistic regression model to predict the probability of slump slide occurrence. The proposed model was verified for both slide and non-slide cases. The regression analysis depicts the impact of channel width, river sinuosity index, riverbank erosion, channel shape condition and distance to river. Excluding the sinuosity index, the impact of the other independent variables examined was found to be significant. Occurrence of riverbank erosion around the slide locations was the most significant predictor factor. A channel width of less than 1000 m was ranked as the second most significant variable. The proposed model can aid in locating high-risk areas on levees in order to take prompt protective measures, increase monitoring efforts and enable early response under emergency conditions.
Abstract





Estuarine Influence on Biogeochemical Properties of the Alabama Shelf during the Fall Season
Estuarine-shelf exchange can drive strong gradients in physical and biogeochemical properties in the coastal zone and exert a significant influence on biological processes and patterns. Physical, biogeochemical, and plankton data from an across-shelf transect extending south of Mobile Bay, Alabama, in conjunction with regional time series data, were used to determine the relative importance of estuarine-shelf interactions on the physical-biological structuring of the shelf environment during fall conditions (i.e., well-mixed, low discharge).This period was also characterized by a relatively unique weather event associated with the remnants of Hurricane Patricia, which drove a meteorological flushing of estuarine water onto the shelf. Survey data indicated generally low N:P ratios across the shelf, with slightly elevated dissolved inorganic nitrogen in the Region of Freshwater Influence (ROFI) that extended approximately 30 km offshore. The ROFI had higher values of chlorophyll-a, diatom-specific production, marine snow, and primary productivity, with notable contributions from the larger size cells (
Abstract Document





Evaluation of a Synthetic Rainfall Model, P-CLIPER, for Use in Coastal Flood Modeling
With the projected increase in both tropical cyclone (TC) intensity and proportion of the global population living near the coast, adequate preparation to protect against TC flooding is in the economic interest of coastal cities worldwide. Numerical models that describe TC properties, e.g., storm surge and wind fields, are currently employed to simulate the component of flooding that results from seawater inundation of areas along the coast (i.e., saltwater flooding). However, without the inclusion of freshwater flooding, contributed by inland surface flow and direct precipitation, a total water level (TWL) system for TC flooding lacks a complete picture of the actual coastal flood levels. Working toward a true TWL system, this research investigates the efficacy of the simple and efficient parametric TC rainfall model P-CLIPER (PDF Precipitation-Climatology and Persistence) to provide historically representative TC rainfall to a TWL system. This research demonstrates the success of this novel use of P-CLIPER through calibration and validation to the Tar
Document





Evaluation of the APEX Model to Simulate Runoff Quality from Agricultural Fields in the Southern Region of the U.S.
The Agricultural Policy Environmental eXtender (APEX) model has been widely applied to assess phosphorus (P) loss in runoff water and has been proposed as a model to support practical decisions regarding agricultural P management, as well as a model to evaluate tools such as the P Index. The aim of this study is to evaluate the performance of APEX to simulate P losses from agricultural systems to determine its potential use for refinement or replacement of the P Index in the southern region of the United States. Uncalibrated and calibrated APEX model predictions were compared against measured water quality data from row crop fields in North Carolina and Mississippi and pasture fields in Arkansas and Georgia. Calibrated models satisfactorily predicted event-based surface runoff volumes at all sites (Nash-Sutcliffe efficiency [NSE]
Abstract





FloodViz: Visual Analytics for Assessment and Interpretation of Simulated River Flooding
The FloodViz project involves the development and testing of visual analytics software to enable scientists and forecasters to better interpret and distribute hydrologic information. This software will be useful in the research community as an interpretation tool for river level and flood data. The tools developed serve as a useful platform for hydrologic forecasters within the National Weather Service to more quickly and accurately determine areas at risk for flooding and allow NOAA river forecasters to better visualize the extent of flooding. Additionally, these tools allow forecasters to relay more information to the emergency management community while issuing forecasts to help protect lives, property and the nation.
FloodViz Web Site Email Contact





Forecasting Episodic Changes in Hurricane Intensity and Structure over the Gulf of Mexico
The primary goal of this proposed initial one-year project is to provide greater insight into forecasting time-sensitive trends of rapid formation, changing intensity, and changing wind field area (or size) of hurricanes over the Gulf Mexico in the interest of reducing the uncertainty in the risk posed to Gulf Coast residents and infrastructure. The focus would be to identify key features or processes present in the ambient atmosphere and in the Gulf of Mexico that led to critical episodic changes in the intensity and structure of recent hurricanes: Humberto, Gustav, and Ike.
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Functioning of Coastal River-Dominated Ecosystems and Implications for Oil Spill Response: From Observations to Mechanisms and Models
Coastal river-dominated oceans are physically complex, biologically productive, and intimately connected to human socioeconomic activity. The Deepwater Horizon blowout and subsequent advection of oil into coastal waters of the northern Gulf of Mexico (nGOM) highlighted the complex linkages among oceanographic processes within this river-dominated system and knowledge gaps about it that resulted in imprecise information on both oil transport and ecosystem consequences. The interdisciplinary research program implemented through the CONsortium for oil exposure pathways in COastal River-Dominated Ecosystems (CONCORDE) is designed to identify and quantitatively assess key physical, biological, and geochemical processes acting in the nGOM, in order to provide the foundation for implementation of a synthesis model (coupled circulation and biogeochemistry) of the nGOM shelf system that can ultimately aid in prediction of oil spill transport and impacts.
Abstract and Document site





GeoVol-Geospatial Volume Rendering
This project created software using direct volume rendering techniques that achieved real-time performance and high image quality. A user study was conducted to compare the implemented volume rendering technique with state-of-the-art isosurface rendering to examine hurricane data. The results of the study established that both volume rendering and isosurface visualizations were effective in examining data from computer simulations of hurricanes. Because of the higher image quality and the interactive frame rates, direct volume rendering was preferred. Future studies will be conducted to quantify performance differences between using the traditional 2D methods and the 4D methods.
Hurricane Lili Visualization Email Contact





Health and Productivity of Louisiana Salt Marshes
This study will allow the identification of hotspots of marsh degradation in Louisiana by evaluating marsh biophysical characteristics including distribution of chlorophyll content, green leaf area and green marsh canopy cover. This assessment of marsh health and productivity is due to the Deepwater Horizon oil spill. NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images will be used to retrieve and map these characteristics across the coastal Louisiana salt marshes before and after the spill. The maps and tools produced from the study will be helpful to coastal managers across Louisiana as they evaluate and prioritize the marsh restoration effort which will take place due to the oil spill. Tangible map products will be generated for the first time that can quantitatively assess the effect of the restoration activities and speed of marsh ecosystem recovery.
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Hurricane Landfall Estimation and Storm Surge
The storm surge of Hurricane Katrina, which made landfall in Mississippi and Louisiana in 2005, was unprecedented for its elevation, area coverage, and levee breaches. Due to the storm surge, areas along the Gulf Coast were severely flooded and destroyed. GRI is addressing recent Mississippi and Louisiana storm surge issues using the finite element model ADCIRC. The research will facilitate answers to the sensitivity of the storm surge in Mississippi to wind profiles of major hurricanes, as well as to hurricane eye size and landfall estimation.





Hydrological and Biogeochemical Controls of Seasonality in Dissolved Organic Matter Delivery to a Blackwater Estuary
Changes in riverine discharge of dissolved organic matter (DOM) serves as an indicator of linkages between terrestrial ecosystem and receiving aquatic environments. In this study, we test the hypothesis that the seasonal variability of DOM in an estuary fed by a blackwater river is primarily controlled by water discharge and also modified by photochemical and biological processes. We collected surface water samples during 4-week-long field campaigns to the lower Pearl River estuary located in southeastern Louisiana, two during high discharge in spring and two during low discharge in winter and summer, respectively. DOM composition was determined using spectrofluorometric indices and a site-specific parallel factor model, and dissolved organic carbon (DOC) concentrations. Spring samples with low salinity showed higher abundance of terrestrial, humic-like DOM and higher DOC concentrations, indicating the export of flood plain-derived DOM during high discharge. In contrast, summer and winter samples with high salinity had greater proportions of labile DOM and higher biological and fluorescence indices, which may reflect enhanced photochemical and biological degradation during summer and better preservation of labile DOM in winter. Spring DOM displayed highly variable source and quality character, relative to winter and summer samples.
Abstract and Research





Inflow of Shelf Waters into the Mississippi Sound and Mobile Bay Estuaries in October 2015
The exchange of coastal waters between the Mississippi Sound (MSS), Mobile Bay and Mississippi Bight is an important pathway for oil and pollutants into coastal ecosystems. This study investigated an event of strong and persistent inflow of shelf waters into MSS and Mobile Bay during October 2015 by combining in-situ measurements, satellite ocean color data and ocean model predictions. Navy Coastal Ocean Model (NCOM) predicted high salinity shelf waters continuously flowing into the estuarine system, and forecasted low salinity waters trapped inside the estuaries which did not flush out until the passage of tropical cyclone Patricia





Inland Navigation: Environmental Sustainability
Inland Navigation: Environmental Sustainability provides the current state of environmental preservation procedures for inland waterways. It presents an overview of ecosystem sustainability procedures currently used. This technical report examines environmental considerations for construction, as well as operation and restoration of inland freshwater waterways in the continental United States, which includes the lower Mississippi and lower Columbia rivers. Topics include Hydrology and hydraulics; Sedimentation, dredging, and disposal; Water quality; Habitat (aquatic, terrestrial, wetlands); Migratory fish and birds; Historic preservation; and Restoration and environmental laws directed to waterway design and operation. This report is a valuable reference for those involved with waterway design and operations and will be of use as an educational text for the academic community.
Book





Investigating the Correlation between Radar Backscatter and In Situ Soil Property Measurements
Utilizing remote sensing techniques to extract soil properties can facilitate several engineering applications for large-scale monitoring and modeling purposes such as earthen levees monitoring, landslide mapping, and off-road mobility modeling. This study presents results of statistical analyses to investigate potential correlations between multiple polarization radar backscatter and various physical soil properties. The study was conducted on an approximately 3 km long section of earthen levees along the lower Mississippi river as part of the development of remote levee monitoring methods. Polarimetric synthetic aperture radar imagery from UAVSAR was used along with an extensive set of in situ soil properties. The following properties were analyzed from the top 30
Abstract and Document





Land use and land cover control on the spatial variation of dissolved organic matter across 41 lakes in Mississippi, USA
While dissolved organic matter (DOM) is an important indicator of water quality, land use and land cover (LULC) of watersheds define the source, quality, and quantity of DOM delivered to a waterbody. This study examined the influence of various LULC classes in the spatial distribution of DOM in 41 lakes across the state of Mississippi. To scale the influence of LULC classes on DOM distribution, we have classified 41 lakes into five clusters based on DOM compositions determined by parallel factor analysis. Four major DOM compositions including terrestrial humic-like (C1), microbial humic-like (C2), soil-derived humic-like (C3), and tryptophan-like or tyrosine like (C4) components were identified. Higher amounts of terrestrial humic-like and soil-derived humic-like DOM compositions were observed in lakes within watersheds dominated by forested, barren, wetlands, or agricultural areas with exposed unconsolidated soil. Higher amounts of microbial humic-like composition were observed in lakes surrounded by hay/pasture, rangeland, and urbanized areas. Additionally, protein-like DOM and ammonia were more enriched in larger lakes, indicating the influences of photochemical reactions. High amounts of forested areas and higher concentrations of terrestrial humic-like DOM composition were identified in all lakes suggesting forested areas in the watershed as the principal source of DOM in Mississippi lakes.
Research Document





Linking Cultural, Biological and Economic Values into Wetland Programs: Mississippi Band of Choctaw Indians' Pearl River Wetland Demonstration Project
This project aims to develop procedures for more reliably regenerating rivercane and for planting potential restoration sites in the Coastal Plain, and for maintenance of stands for cultural use by native peoples. We are assessing ecological factors associated with the establishment and maintenance of rivercane stands, developing methods for vegetative propagation of rivercane from rhizome segments, and attempting to transfer our findings directly to the Choctaw and other American Indian groups through local and regional symposia, workshops, and field days.
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Mapping of Invasive Phragmites (Common Reed) in Gulf of Mexico Coastal Wetlands Using Multispectral Imagery and Unmanned Aerial Systems
In coastal wetlands of the Gulf of Mexico, the invasive plant species Phragmites australis (common reed) rapidly alters the ecology of a site by shifting plant communities from heterogeneous mixtures of plant species to homogenous stands of Phragmites. Phragmites grows in very dense stands at an average height of 4.6 m and outcompetes native plants for resources. To restore affected wetlands, resource managers require an accurate map of Phragmites locations. Previous studies have used satellite and manned aircraft-based remote-sensing images to map Phragmites in relatively large areas at a coarse scale; however, low-altitude high-spatial-resolution pixel-based classification approaches would improve the mapping accuracy. This study explores the supervised classification methods to accurately map Phragmites in the coastal wetlands at the delta of the Pearl River in Louisiana and Mississippi, USA, using high-resolution (8 cm ground sample distance; GSD) multispectral imagery collected from a small unmanned aerial system platform at an altitude of 120 m. We create a map through pixel-based Support Vector Machines (SVM) classification using blue, green, red, red edge, and near-infrared spectral bands along with a digital surface model (DSM), vegetation indices, and morphological attribute profiles (MAPs) as features. This study also demonstrates the effects of different features and their usefulness in generating an accurate map of Phragmites locations. Accuracy assessment based on a) a subset of training/testing samples (to show classifier performance) and b) the entire ground reference (GR) map (to show the quality of mapping) is demonstrated. Kappa, overall accuracy (OA), class accuracies, and their confidence intervals (CIs) are reported. An OA of 91% and kappa of 63 is achieved. The results of this study indicate that features such as MAPs are very useful in accurately mapping invasive Phragmites compared with existing region-based approaches.
Abstract and Document





Micromechanics of Undrained Response of Dilative Granular Media Using a Coupled DEM-LBM Model: A Case of Biaxial Test
In this paper, the Discrete Element Method (DEM) is coupled with the Lattice-Boltzmann Method (LBM) to model the undrained condition of dense granular media that display significant dilations under highly confined loading. DEM-only models are commonly used to simulate the micromechanics of an undrained specimen by applying displacements at the domain boundaries so that the specimen volume remains constant. While this approach works well for uniform strain conditions found in laboratory tests, it does not realistically represent non-uniform strain conditions that exist in the majority of real geotechnical problems. The LBM offers a more realistic approach to simulate the undrained condition since the fluid can locally conserve the system volume. To investigate the ability of the DEM-LBM model to effectively represent the undrained constraint while conserving volume and accurately calculating the stress path of the system, a two-dimensional biaxial test is simulated using the coupled DEM-LBM model, and the results are compared with those attained from a DEM-only constant volume simulation
Abstract Document





Naval Coastal Ocean Model (NCOM)/Hybrid Coordinate Ocean Model (HYCOM)
NOAA's Office of Oceanic and Atmospheric Research entrusted GRI to study two versions for each of these models- their global and Gulf of Mexico adaptations. Data was analyzed from instruments tethered to floating and moored buoys, as well as unmanned gliders that look like miniature submarines. The goal was to determine the accuracy of the four model forecasts, as well as their ranking with respect to each other.
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Nitrogen and Organic Carbon Contents of Agricultural Drainage Ditches of the Lower Mississippi Alluvial Valley
Use of agricultural fertilizers as a means of increasing production has resulted in excessive nutrient loading to agricultural drainage ditches, contributing to the Gulf of Mexico hypoxic zone. Drainage ditches can have wetland characteristics and functionality, including the capacity to remediate nutrient loading, which can be promoted using management practices. The purpose of this study was to assess relationships between organic carbon (C) and nitrogen (N) contents of drainage ditch sediment and waters and to evaluate the spatial scope in which organic C is potentially limiting N removal in drainage ditches throughout the Lower Mississippi Alluvial Valley (LMAV).
Abstract





Northern Gulf Institute Integrated Education and Outreach Program
Under this project, National Oceanic and Atmospheric Administration (NOAA), Mississippi State University (MSU) and Dauphin Island Sea Lab (DISL) will work together to lead the effort to combine education and outreach into a single integrated program of a two year duration focusing on issues and opportunities in the Northern Gulf. By implementing education and outreach at the organizational level, drawing on the strengths of the NGI partners and NOAA education and outreach professionals in the Northern Gulf region, and maintaining an identifiable presence at each NGI partner by building a team with members at each institution, the education and outreach activities will increase the visibility and understanding of NGI research and will assist the integration of NGI research across partners and scientific themes.
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Nutrient and Sediment Runoff from Agricultural Landscapes with Varying Suites of Conservation Practices in the Mississippi Alluvial Valley
Increasing concern regarding environmental degradation in coastal areas that experience annual hypoxic zones has led to the need for mitigation of nutrient laden runoff from inland landscapes. An annual occurrence of a hypoxic zone in the Gulf of Mexico has led to the development and implementation of nutrient reduction strategies throughout the Mississippi River Basin (MRB). With federal, state, and private financial and technical assistance, landowners have implemented best management practices (BMPs) to combat nutrient and sediment nonpoint source pollution; however, the effectiveness of these BMPs alone or utilized together has not been quantified. This study uses a field-scale, paired watershed approach in two watersheds in the Mississippi Alluvial Valley to test for differences in sediment and nutrient runoff concentrations between four management systems.
Abstract and publication site





Pollution assessment and land use land cover influence on trace metal distribution in sediments from five aquatic systems in southern USA
Trace elements and heavy metals concentrate in aquatic sediments, potentially endangering benthic organisms. Comparing the concentration of metals in different aquatic bodies will help evaluate their accumulation and distribution characteristics within these systems. Metal pollution and enrichment indices in sediments from diverse aquatic systems in Southern USA, including agricultural ponds, man-made reservoir, river, swamp, and coastal environment were investigated. Following total digestion of the sediments, the concentrations of chromium (Cr), cobalt (Co), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), antimony (Sb), lead (Pb), and uranium (U) were measured using inductively coupled plasma-mass spectrometry (ICP-MS). Pb was found to be highly enriched in the sediment samples from all five environments. The samples from coastal and agricultural ponds showed highest degree of anthropogenic modification (enrichment factor
Research Document





Potential for recycling of suspended solids and nutrients by irrigation of tailwater from tailwater recovery systems
Within the Lower Mississippi Alluvial Valley, conservation practices are being utilized to mitigate nutrient loading to streams from agricultural landscapes. This study was conducted to determine the potential to use solids, phosphorus (P) and nitrogen (N) captured by tailwater recovery (TWR) systems for reuse onto production fields through irrigation applications.
Abstract and Document





Quantifying Capture and Use of Tailwater Recovery Systems
The government has provided financial assistance on approximately 200 tailwater recovery systems in the state of Mississippi, and more in other states. The objective of this study was to quantify surface water capture and use within 31 tailwater recovery ditches (TWR) and on-farm storage reservoirs (OFS), so that conservation benefits could be evaluated. Water-level data were combined with system dimensions, rainfall data, and evaporation estimates to assess total gains and losses over the course of a year. Systems had a net positive balance of approximately 2,200,000 m3m3 (2,200 ML) of captured surface water. Losses from evaporation and infiltration were between 8.68 and 10.97
Abstract and Document





Reduction of solids and nutrient loss from agricultural land by tailwater recovery systems
Best management practices are being implemented throughout the Lower Mississippi River Alluvial Valley with the aim of alleviating pressures placed on downstream aquatic systems by sediment and nutrient losses from agricultural land; however, research evaluating the performance of tail-water recovery (TWR) systems, an increasingly important practice, is limited. This study evaluated the ability of TWR systems to retain sediment and nutrients draining from agricultural landscapes.
Abstract





Representation of Solid and Nutrient Concentrations in Irrigation Water from Tailwater-Recovery Systems by Surface Water Grab Samples
Tailwater recovery (TWR) systems are being implemented on agricultural landscapes to create an additional source of irrigation water. Existing studies have sampled TWR systems using grab samples; however, the representation of solids and nutrient concentrations in these samples to water being irrigated from TWR systems has yet to be investigated. In order to test whether grab samples are representative of water pumped from TWR systems for irrigation use, this study compared concentrations of total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), total Kjeldahl nitrogen (TKN), nitrate-nitrite (NO−3NO−2NO3−NO2−), and ammonium (NH 4NH4 ). Grab samples were collected simultaneously from the surface water and from the respective outflow of irrigation infrastructure in six TWR systems. Comparison of 14 irrigation events showed TSS, TP, TN, TKN, NO−3NO−2NO3−NO2−, and NH 4NH4 did not differ (Pillai’s trace5,1=0.307trace5,1=0.307, p>0.5p>0.5) between surface water grab samples and irrigation water samples. No differences (p>0.05p>0.05) were found for TN, TP, NH 4NH4 , and TKN across sites. This research suggests surface water grab samples from TWR systems represent the solid and nutrient concentrations being irrigated at that moment of time.
Tailwater-Recovery Systems ...Grab Samples





Research on the Performance of Tail-Water Recovery Systems to Alleviate Downstream Aquatic Systems
Best management practices are being implemented throughout the Lower Mississippi River Alluvial Valley with the aim of alleviating pressures placed on downstream aquatic systems by sediment and nutrient losses from agricultural land; however, research evaluating the performance of tail-water recovery (TWR) systems, an increasingly important practice, is limited. This study evaluated the ability of TWR systems to retain sediment and nutrients draining from agricultural landscapes.
Abstract





Satellite Rainfall Applications for Surface Hydrology
GRI has evaluated results which examine how soil moisture states simulated by land surface models are impacted when forced with various precipitation datasets. These datasets are from a collection of Global Precipitation Mission satellite constellation configurations gathered over the continental United States.
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Sequential Applications of Diquat to Control Flowering Rush (Butomus Umbellatus L.) in Mesocosms. Journal of Aquatic Plant Management
Flowering rush (Butomus umbellatus L.) is an aggressive, invasive, aquatic plant spreading throughout water bodies in the northern United States and southern Canada, displacing many native aquatic/wetland plants. This can disrupt ecosystem processes and affect human uses of water bodies. Operational management in Detroit Lakes, MN, reduced flowering rush biomass and propagules by >80% using two sequential, submersed applications of diquat (0.37 mg L-1 ) per growing season (4 wk apart). However, in dense colonies, long-term control has taken years to achieve, suggesting a more aggressive treatment regime may be necessary. A mesocosm study was initiated in 2015 and repeated in 2016 to further investigate diquat (0.37 mg L-1 ; 12 h exposure time) efficacy using one to four biweekly (every other week) sequential herbicide applications to improve flowering rush control.
Abstract Journal of Plant and Aquatic Management,





Southern P Indices, Water Quality Data, and Modeling (APEX, APLE, and TBET) Results: A Comparison
Phosphorus (P) Indices in the southern United States frequently produce different recommendations for similar conditions. We compared risk ratings from 12 southern states (Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and Texas) using data collected from benchmark sites in the South (Arkansas, Georgia, Mississippi, North Carolina, Oklahoma, and Texas). Phosphorus Index ratings were developed using both measured erosion losses from each benchmark site and Revised Universal Soil Loss Equation 2 predictions; mostly, there was no difference in P Index outcome. The derived loss ratings were then compared with measured P loads at the benchmark sites by using equivalent USDA–NRCS P Index ratings and three water quality models (Annual P Loss Estimator [APLE], Agricultural Policy Environmental eXtender [APEX], and Texas Best Management Practice Evaluation Tool [TBET]). Phosphorus indices were finally compared against each other using USDA–NRCS loss ratings model estimate correspondence with USDA–NRCS loss ratings. Correspondence was 61% for APEX, 48% for APLE, and 52% for TBET, with overall P index correspondence at 55%. Additive P Indices (Alabama and Texas) had the lowest USDA–NRCS loss rating correspondence (31%), while the multiplicative (Arkansas, Florida, Louisiana, Mississippi, South Carolina, and Tennessee) and component (Georgia, Kentucky, and North Carolina) indices had similar USDA–NRCS loss rating correspondence—60 and 64%, respectively. Analysis using Kendall’s modified Tau suggested that correlations between measured and calculated P-loss ratings were similar or better for most P Indices than the models.
Document Document Site





Spatial and spectral Hyperspectral Classification Using Local Binary Patterns and Markov Random Fields
Local binary patterns (LBPs) have been extensively used to yield spatial features for the classification of general imagery, and a few recent works have applied these patterns to the classification of hyperspectral imagery. Although the conventional LBP formulation employs only the signs of differences between a central pixel and its surrounding neighbors, it has been recently demonstrated that the difference magnitudes also possess discriminative information. Consequently, a sign-and-magnitude LBP is proposed to provide a spatial
Abstract Document Site





Spatial Technology and High Performance Computing for Improving Prediction of Surface Water Quality
This project will contribute generally to improved coastal management decisions by demonstrating the best use of new data and modeling technologies for ecosystem management. It will specifically lead to improved management of Mobile Bay, with benefits to the Alabama-Mississippi coastal zone and Mississippi Sound.
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Spatial Variation and Temporal Trend of Water Quality
NGI conducted ground truth observations and standardize algorithms to produce and evaluate the spatial and temporal variations of water quality parameters in the Northern Gulf of Mexico (NGOM). The effort is aimed at improving the monitoring of the NGOM ecosystem based on remote sensing and understanding the dynamics of harmful algae blooms in the region.
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The Science of William M. Gray: His Contributions to the Knowledge of Tropical Meteorology and Tropical Cyclones
Advances in knowledge in tropical meteorological research are discussed in the context of contributions made by Professor William M. Gray. Gray pioneered the compositing approach to observational tropical meteorology through assembling of global radiosonde data sets and tropical cyclone research flight data. In the 1970s he made fundamental contributions to knowledge of convective-larger scale interactions. Throughout his career he wrote seminal papers on tropical cyclone structure, cyclogenesis, motion and seasonal forecasts. His conceptual development of a seasonal genesis parameter also laid an important framework for both seasonal forecasting as well climate change studies on tropical cyclones. His work was a blend of both observationally-based studies as well as the development of theoretical concepts. This paper reviews the progress in knowledge in the areas where Dr. Gray provided his largest contributions and describes the scientific legacy of Gray
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Torpedograss control via submersed applications of systemic and contact herbicides in mesocosms
Torpedograss control via submersed applications of systemic and contact herbicides in mesocosms
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UAV Research with NOAA
GRI scientists are using UAVs to assess the speed and rate of how rivers flow and rise and where the water goes, especially in flood type conditions. Partnering with NOAA, both are helping the U.S. to become a “Weather Ready Nation.” This effort can help prevent the loss of life and property before, during and after natural disasters, such as flooding, created by tropical storms and hurricanes. They are conducting research and gaining invaluable environmental and situational data along the lower Pearl River watershed, south of Bogalusa, Louisiana, all the way down to what is called the tidal plain.
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Using Unmanned Aerial Vehicles for High-Resolution Remote Sensing to Map Invasive Phragmites Australis in Coastal Wetlands
The wetland plant species, Phragmites australis, is present on every continent except Antarctica. Both native and non-native subspecies thrive in the USA with the non-natives quickly displacing native wetland plants. Along the Gulf Coast, Phragmites grows in very dense stands, and at heights of greater than 4.6 m, is usually the tallest grass species in a wetland, estuary, and marsh ecosystems. Phragmites is known to alter the ecology of these wetland systems making them less suitable as habitat for many species of flora and fauna. Furthermore, Phragmites presents a navigation hazard to smaller boats by impairing visibility along shorelines and around bends of canals and rivers. Management efforts targeting non-native Phragmites rely heavily on accurately mapping invaded areas. Historically, mapping has been done through walking the perimeter of a stand with a Global Positioning System (GPS) unit, using satellite imagery, or through the use of aerial photography from manned aircraft. These methods are time consuming, are expensive, can have an inadequate resolution, and in some cases are prone to human error. In this work, an Unmanned Aerial System (UAS) was used to capture visible imagery to create a basin-wide distribution map of a large wetland along the US Pearl River delta in southeastern Louisiana. The imagery was collected in the summer and individual images were mosaicked to create a larger map. We then evaluated the use of texture analysis on the mosaics to automatically map the invasive. Specifically, Gabor filters, grey level co-occurrence matrices, segmentation-based fractal texture analysis, and wavelet-based texture analysis were compared for mapping the Phragmites. Our experimental results, conducted using the imagery we collected over four study areas (approximately 2250 ha) along the US Pearl River delta, indicate the proposed texture-based approach yields an average accuracy of 85%, an average kappa accuracy of 70%. These maps have shown to be very useful for resource managers to hasten the eradication efforts of Phragmites.
Abstract and Document





Variation in Dissolved Organic Matter, Trace Metals, and Acidification Parameters in the Western Mississippi Sound
The total amount of oysters harvested in the Mississippi Sound has declined by 85.71% over the last 13 years. The objective of this study was to assess the influence of water quality on the oysters, specifically the temporal changes in dissolved organic matter (DOM), trace elements, and ocean acidification parameters over the largest oyster bed in the western Mississippi Sound.
Abstract





Visualization Techniques for Improving Understanding of Severe Storms
This project advances the visual analysis tools to increase a modeler or analyst's ability to understand hurricane structure, intensity and dynamics. The project focuses on developing new 2D and 3D visualization tools which produce visualization products that can be made publicly available, easily interpreted and can be viewed on personal computers or used in television coverage. The goal is to create a hurricane visualization system that accepts both simulated and measured data as input and put all the data into a single geographic context.
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WISDOM - Weather In-Situ Deployment Optimization Method
GRI scientists and students are participating in WISDOM, the Weather In-Situ Deployment Optimization Method research program that seeks to improve hurricane forecasting time by three to seven days before a storm's landfall by providing wind and atmospheric data in areas of the Atlantic basin that are poorly observed. The WISDOM program launches small super-pressure balloons with payloads that include GPS and satellite radio communications capabilities.
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