Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 29 of 29

Full-Text Articles in Physical Sciences and Mathematics

Beyond The Tide: A Comprehensive Guide To Sea-Level-Rise Inundation Mapping Using Foss4g, Levente Juhasz, Jinwen Xu, Randall W. Parkinson Nov 2023

Beyond The Tide: A Comprehensive Guide To Sea-Level-Rise Inundation Mapping Using Foss4g, Levente Juhasz, Jinwen Xu, Randall W. Parkinson

GIS Center

No abstract provided.


Hydrologic Properties Of Mangrove And Sawgrass Peat In Shark River Slough, Everglades, Florida, Nicole Cordoba May 2022

Hydrologic Properties Of Mangrove And Sawgrass Peat In Shark River Slough, Everglades, Florida, Nicole Cordoba

FIU Electronic Theses and Dissertations

Peat sediments are the foundation of most wetlands, acting as a medium for water to flow through, governed by hydraulic conductivity, and as a potential source of nutrients. Shark River Slough is a known, main fresh waterway for Everglades National Park, distributing essential nutrients and freshwater into the wetland. Hydraulic conductivity was calculated through experimental (both in situ water and higher salinity water) falling head tests performed on mangrove and sawgrass peat cores. Nutrient concentrations were analyzed for the pore water released during hydrologic testing. Hydraulic conductivity values were higher in the sawgrass peat than the mangrove peat. No significant …


Integrating Compound Flood Conditions Through 2d Hydraulic Modeling For Simulating Flood Risk Processes In Coastal Cities, Francisco Pena Guerra Mr. Oct 2021

Integrating Compound Flood Conditions Through 2d Hydraulic Modeling For Simulating Flood Risk Processes In Coastal Cities, Francisco Pena Guerra Mr.

FIU Electronic Theses and Dissertations

Low elevation coastal karst environments are highly vulnerable to flooding conditions due to climate change. Trends in rising global temperatures have increased the frequency and intensity of extreme precipitation, hydrometeorological phenomena and sea level rise, exacerbating the impact of pluvial, fluvial, coastal and groundwater flood hazards. Compound flooding events amplify flood hazards and pose a higher threat to residents and infrastructure in unison compared to independent phenomena. Recent advancements in coupling hydrologic and hydraulic modeling frameworks have improved our ability to account for the combined effects of extreme pluvial, fluvial, and coastal flood hazards. This innovation in the hydroinformatics field …


Hydrogeophysical Characterization And Imaging In The Mangrove Lakes Region Of Everglades National Park And Big Pine Key, Florida, Usa, Michael Eyob Kiflai Jul 2020

Hydrogeophysical Characterization And Imaging In The Mangrove Lakes Region Of Everglades National Park And Big Pine Key, Florida, Usa, Michael Eyob Kiflai

FIU Electronic Theses and Dissertations

Coastal groundwater aquifers are susceptible to saltwater intrusion from natural and anthropogenic sources. Everglades National Park (ENP) has been adversely impacted by past human activities that altered freshwater flow through the system. In Big Pine Key (BPK), the flat and low-lying topography less than 2m makes the freshwater lens vulnerable to tidal and storm surge events. This study investigated different inversion scenarios and used Electrical Resistivity Tomography (ERT) and Electromagnetic (EM) survey to characterize the spatial and temporal change of the groundwater chemistry and image the aquifers. In Big Pine Key, Hurricane Irma made landfall as a category 4 storm …


Modeling Drought, Drought Teleconnection, And Its Effect On Groundwater Level Dynamics In The Biscayne Aquifer, Anteneh Z. Abiy Apr 2020

Modeling Drought, Drought Teleconnection, And Its Effect On Groundwater Level Dynamics In The Biscayne Aquifer, Anteneh Z. Abiy

FIU Electronic Theses and Dissertations

Developing a self-sufficient water supply system in Southeast Florida is one input to the success of the ongoing restoration effort in the Everglades. Maintaining a high groundwater level in the urban side of the Biscayne Aquifer (BA) is important to sustain the urban water supply. However, the long-term groundwater table condition in the Biscayne Aquifer (BA) is threatened by a combination of drought, groundwater pumping, and sea-level rise. Further, the long-term drought pattern, drought drivers, and the aquifer’s response to drought and other stress conditions are not well known. As a result, options that would help to maintain a high …


Developing Ocean Color Algorithm Using Moderate Resolution Imaging Spectroradiometer (Modis) Sensor For Shallow Coastal Water Bodies, Mohd Manzar Abbas Jun 2018

Developing Ocean Color Algorithm Using Moderate Resolution Imaging Spectroradiometer (Modis) Sensor For Shallow Coastal Water Bodies, Mohd Manzar Abbas

FIU Electronic Theses and Dissertations

This study analyses the spatial and temporal variability of chlorophyll-a in Chesapeake Bay; assesses the performance of Ocean Color 3M (OC3M) algorithm; and develops a novel algorithm to estimate chlorophyll-a for coastal shallow water. The OC3M algorithm yields an accurate estimate of chlorophyll-a concentration for deep ocean water (RMSE=0.016), but it failed to perform well in the coastal water system (RMSE=23.17) of Chesapeake Bay. A novel algorithm was developed which utilizes green and red bands of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The novel algorithm derived the chlorophyll-a concentration more accurately in Chesapeake Bay (RMSE=4.20) than the OC3M algorithm. …


Environmental Dynamics Of Dissolved Organic Matter And Dissolved Black Carbon In Fluvial Systems: Effects Of Biogeochemistry And Land Use, J. Alan Roebuck Jr. May 2018

Environmental Dynamics Of Dissolved Organic Matter And Dissolved Black Carbon In Fluvial Systems: Effects Of Biogeochemistry And Land Use, J. Alan Roebuck Jr.

FIU Electronic Theses and Dissertations

Black carbon (BC) is an organic residue formed primarily from biomass burning (e.g., wildfires) and fossil fuel combustion. Until recently, it was understood that BC was highly recalcitrant and stabilized in soils over millennial scales. However, a fraction of the material can be solubilized and transported in fluvial systems as dissolved BC (DBC), which represents on average 10% of the global export of dissolved organic carbon (DOC) from rivers to coastal systems. The composition of DBC controls its reactivity, and it has been linked with a variety of in-stream processes that induce both carbon sequestration and evasion of CO₂ from …


Investigating The Effects Of Land-Cover Change On The Hydrologic Conditions Of A Restored Agricultural Area In Everglades National Park, Dillon Reio Jun 2017

Investigating The Effects Of Land-Cover Change On The Hydrologic Conditions Of A Restored Agricultural Area In Everglades National Park, Dillon Reio

FIU Electronic Theses and Dissertations

In the Florida Everglades, remodeling of natural wetlands to promote agriculture and human settlement, have profoundly altered its hydrologic regime. As a result of anthropogenic changes, many restoration programs have been initiated to restore hydrologically controlled wetland ecosystems. One such restoration project that has been ongoing for the past 27 years is the Hole-in-the-Donut restoration program in Everglades National Park. The restoration program is unique in that it utilized an unorthodox technique to restore the landscape. The viability of the restoration technique was assessed by coupling long-term hydrologic and evapotranspiration data with water chemistry analyses. Key results indicated that the …


Water-Rock Interactions And Seasonal Hydrologic Processes In Constructed Everglades Tree Islands, Andres E. Prieto Estrada Jul 2016

Water-Rock Interactions And Seasonal Hydrologic Processes In Constructed Everglades Tree Islands, Andres E. Prieto Estrada

FIU Electronic Theses and Dissertations

The decline of tree islands in the freshwater-Everglades wetland because of hydrologic manipulation, has compromised valuable ecosystem services. Although the role of tree islands in maintaining freshwater quality stems largely from evapotranspiration processes, fundamental questions remain about the effects of different geologic materials on their hydrogeochemical functioning. To reduce this uncertainty, the lithological composition of a set of man-made tree islands was investigated coupled with long-term hydrologic and hydrochemical data. Key results indicate that limestone substrates and peat substrates with elevated proportions of sand, facilitated surface water-groundwater interactions and mineral dissolution. However, limestone-based islands were more effective in lowering the …


Simple Models For Underdamped Slug Tests In High Permeability Aquifers, Maria E. Marquez Jun 2016

Simple Models For Underdamped Slug Tests In High Permeability Aquifers, Maria E. Marquez

FIU Electronic Theses and Dissertations

Accurate hydraulic conductivity values are necessary for understanding groundwater flow. Methods for estimating hydraulic conductivity show limitations because measured values vary several orders of magnitude in high permeability aquifers. Slug tests, while cost and time efficient, result in values lower than expected. It is proposed that underdamped behavior of water in a well is similar to mass on a damped spring; hence, models constructed to simulate behavior independent of aquifer effects might replicate some tests. The Poiseuille and Darcy-Weisbach models, and extensions of these models considering entry/exit effects, are applied to an aquifer-free laboratory test, and real wells. Aquifer-free laboratory …


Hydrogeochemical Modeling Of Saltwater Intrusion And Water Supply Augmentation In South Florida, Yonas T. Habtemichael Apr 2016

Hydrogeochemical Modeling Of Saltwater Intrusion And Water Supply Augmentation In South Florida, Yonas T. Habtemichael

FIU Electronic Theses and Dissertations

The Biscayne Aquifer is a primary source of water supply in Southeast Florida. As a coastal aquifer, it is threatened by saltwater intrusion (SWI) when the natural groundwater flow is altered by over-pumping of groundwater. SWI is detrimental to the quality of fresh groundwater sources, making the water unfit for drinking due to mixing and reactions with aquifer minerals. Increasing water demand and complex environmental issues thus force water utilities in South Florida to sustainably manage saltwater intrusion and develop alternative water supplies (e.g., aquifer storage and recovery, ASR).

The objectives of this study were to develop and use calibrated …


Gaseous Carbon Emissions (Methane And Carbon Dioxide) From Wetland Soils In A Re-Created Everglades Landscape, Bradley R. Schonhoff Nov 2015

Gaseous Carbon Emissions (Methane And Carbon Dioxide) From Wetland Soils In A Re-Created Everglades Landscape, Bradley R. Schonhoff

FIU Electronic Theses and Dissertations

Reducing the rates of greenhouse gas (GHG) emissions is critical in combatting global climate change. Carbon dioxide (CO2) and methane (CH4) are the two most important carbon-based GHGs, for their atmospheric warming potential. Wetlands such as the Florida Everglades play major roles in the global carbon cycle, as varying hydrologic conditions lead to differential production rates of these two GHGs. This study measured CO2 and CH4 emissions in a re-created Everglades ridge-and-slough wetland, where water levels were controlled to reflect natural flood patterns. As expected, lower elevations were flooded longer and produced more CH …


The Effect Of Disturbance And Freshwater Availability On Lower Florida Keys’ Coastal Forest Dynamics, Danielle E. Ogurcak Nov 2015

The Effect Of Disturbance And Freshwater Availability On Lower Florida Keys’ Coastal Forest Dynamics, Danielle E. Ogurcak

FIU Electronic Theses and Dissertations

Coastal forest retreat in the Florida Keys during the 20th century has been attributed to a combination of sea level rise and hurricane storm surge impacts, but the interactions between these two disturbances leading to forest decline are not well understood. The goal of my research was to assess their effects over a period spanning more than two decades, and to examine the relationships between these press and pulse disturbances and freshwater availability in pine rockland, hardwood hammock, and supratidal scrub communities. Impacts and recovery from two storm surges, Hurricanes Georges (1998) and Wilma (2005), were assessed with satellite-derived …


Performance Of High Resolution Satellite Rainfall Products Over Data Scarce Parts Of Eastern Ethiopia, Shimelis B. Gebere, Tena Alamirew, Broder J. Merkel, Assefa M. Melesse Sep 2015

Performance Of High Resolution Satellite Rainfall Products Over Data Scarce Parts Of Eastern Ethiopia, Shimelis B. Gebere, Tena Alamirew, Broder J. Merkel, Assefa M. Melesse

Department of Earth and Environment

Accurate estimation of rainfall in mountainous areas is necessary for various water resource-related applications. Though rain gauges accurately measure rainfall, they are rarely found in mountainous regions and satellite rainfall data can be used as an alternative source over these regions. This study evaluated the performance of three high-resolution satellite rainfall products, the Tropical Rainfall Measuring Mission (TRMM 3B42), the Global Satellite Mapping of Precipitation (GSMaP_MVK+), and the Precipitation Estimation from Remotely-Sensed Information using Artificial Neural Networks (PERSIANN) at daily, monthly, and seasonal time scales against rain gauge records over data-scarce parts of Eastern Ethiopia. TRMM 3B42 rain products show …


Modeling A Phosphorus Credit Trading Program In The Lake Okeechobee Watershed, Juliana Corrales Sep 2015

Modeling A Phosphorus Credit Trading Program In The Lake Okeechobee Watershed, Juliana Corrales

FIU Electronic Theses and Dissertations

Lake Okeechobee is the largest lake in the southeastern United States and is a central component of the hydrology and environment of the Everglades ecosystem in South Florida. The natural state of the lake has been degraded as wetlands and natural habitats in the Lake Okeechobee watershed have been replaced with farms, urban areas, and dairy operations. Excessive phosphorus loadings from these diverse sources have been identified as the leading causes of the lake’s impairment. For more than four decades, many resources have been allocated to regional and local restoration efforts to reduce phosphorus loadings into the lake. However, phosphorus …


Improving Satellite-Based Chlorophyll-A Estimating Algorithms In Shallow, Coastal Waters, Tara Blakey Jul 2015

Improving Satellite-Based Chlorophyll-A Estimating Algorithms In Shallow, Coastal Waters, Tara Blakey

FIU Electronic Theses and Dissertations

This work evaluated the improvement to the accuracy of chlorophyll-a (chl-a) estimating algorithms derived from Sea-Viewing Wide Field-of-View Sensor (SeaWIFS) archives of an optically-shallow, subtropical bay. Preliminary investigation into the in situ chl-a measurements showed that the fine spatial and temporal resolution currently only available through satellite remote sensing are required to adequately understand the dynamics of coastal chl-a. The in situ datasets, however, were found to be useful for developing chl-a algorithms by allowing for 1) identification of appropriate times of year for classifying benthic habitats and 2) the assumption of annually …


Hydrologic Controls Of Coastal Groundwater Discharge In Southern Taylor Slough, Everglades National Park, Florida, Edward Linden Jul 2015

Hydrologic Controls Of Coastal Groundwater Discharge In Southern Taylor Slough, Everglades National Park, Florida, Edward Linden

FIU Electronic Theses and Dissertations

This project empirically determined the controls of groundwater discharge potential and surface water chemistry in southern Taylor Slough, Everglades National Park, Florida. Potential for groundwater discharge was calculated as the difference in equivalent freshwater stage between groundwater and surface water on a daily basis for two sites (upland and coastal) along southern Taylor Slough. Upstream water stages were shown to vary most similarly to the timing of groundwater discharge potential in coastal Taylor Slough. Surface water major ion chemistry did not apparently change as a result of groundwater discharge potential. Surface water major ion chemistry at the coastal site was …


Supervised Classification Of Benthic Reflectance In Shallow Subtropical Waters Using A Generalized Pixel-Based Classifier Across A Time Series, Tara Blakey, Assefa M. Melesse, Margaret O. Hall Apr 2015

Supervised Classification Of Benthic Reflectance In Shallow Subtropical Waters Using A Generalized Pixel-Based Classifier Across A Time Series, Tara Blakey, Assefa M. Melesse, Margaret O. Hall

Department of Earth and Environment

We tested a supervised classification approach with Landsat 5 Thematic Mapper (TM) data for time-series mapping of seagrass in a subtropical lagoon. Seagrass meadows are an integral link between marine and inland ecosystems and are at risk from upstream processes such as runoff and erosion. Despite the prevalence of image-specific approaches, the classification accuracies we achieved show that pixel-based spectral classes may be generalized and applied to a time series of images that were not included in the classifier training. We employed in-situ data on seagrass abundance from 2007 to 2011 to train and validate a classification model. We created …


Numerical Modeling Of The Effects Of Hydrologic Conditions And Sediment Transport On Geomorphic Patterns In Wetlands, Mehrnoosh Mahmoudi Sep 2014

Numerical Modeling Of The Effects Of Hydrologic Conditions And Sediment Transport On Geomorphic Patterns In Wetlands, Mehrnoosh Mahmoudi

FIU Electronic Theses and Dissertations

This dissertation focused on developing a numerical model of spatial and temporal changes in bed morphology of ridge and slough features in wetlands with respect to hydrology and sediment transport when a sudden change in hydrologic condition occurs. The specific objectives of this research were: (1) developing a two-dimensional hydrology model to simulate the spatial distribution of flow depth and velocity over time when a pulsed flow condition is applied, (2) developing a process-based numerical model of sediment transport coupled with flow depth and velocity in wetland ecosystems, and (3) use the developed model to explore how sediment transport may …


Development Of A Methodology That Couples Satellite Remote Sensing Measurements To Spatial-Temporal Distribution Of Soil Moisture In The Vadose Zone Of The Everglades National Park, Luis G. Perez Aug 2014

Development Of A Methodology That Couples Satellite Remote Sensing Measurements To Spatial-Temporal Distribution Of Soil Moisture In The Vadose Zone Of The Everglades National Park, Luis G. Perez

FIU Electronic Theses and Dissertations

Spatial-temporal distribution of soil moisture in the vadose zone is an important aspect of the hydrological cycle that plays a fundamental role in water resources management, including modeling of water flow and mass transport. The vadose zone is a critical transfer and storage compartment, which controls the partitioning of energy and mass linked to surface runoff, evapotranspiration and infiltration. This dissertation focuses on integrating hydraulic characterization methods with remote sensing technologies to estimate the soil moisture distribution by modeling the spatial coverage of soil moisture in the horizontal and vertical dimensions with high temporal resolution.

The methodology consists of using …


Freshwater Resource Supply Modeling For Developed And Undeveloped Watersheds, Kelly C. Gustafson Jul 2014

Freshwater Resource Supply Modeling For Developed And Undeveloped Watersheds, Kelly C. Gustafson

FIU Electronic Theses and Dissertations

Globally, the current state of freshwater resource management is insufficient and impeding the chance at a sustainable future. Human interference within the natural hydrologic cycle is becoming dangerously irreversible and the need to redefine resource managerial approaches is imminent.

This research involves the development of a coupled natural-human freshwater resource supply model using a System Dynamics approach. The model was applied to two case studies, Somalia, Africa and the Phoenix Active Management Area in Arizona, USA. It is suggested that System Dynamic modeling would be an invaluable tool for achieving sustainable freshwater resource management in individual watersheds. Through a series …


Lattice Boltzmann Modeling And Specialized Laboratory Techniques To Determine The Permeability Of Megaporous Karst Rock, Sade Maria Garcia Jun 2013

Lattice Boltzmann Modeling And Specialized Laboratory Techniques To Determine The Permeability Of Megaporous Karst Rock, Sade Maria Garcia

FIU Electronic Theses and Dissertations

The Pleistocene carbonate rock Biscayne Aquifer of south Florida contains laterally-extensive bioturbated ooltic zones characterized by interconnected touching-vug megapores that channelize most flow and make the aquifer extremely permeable. Standard petrophysical laboratory techniques may not be capable of accurately measuring such high permeabilities. Instead, innovative procedures that can measure high permeabilities were applied. These fragile rocks cannot easily be cored or cut to shapes convenient for conducting permeability measurements. For the laboratory measurement, a 3D epoxy-resin printed rock core was produced from computed tomography data obtained from an outcrop sample. Permeability measurements were conducted using a viscous fluid to permit …


Hydrogeophysical Characterization Of Anisotropy In The Biscayne Aquifer Using Geophysical Methods, Albert Yeboah-Forson Jun 2013

Hydrogeophysical Characterization Of Anisotropy In The Biscayne Aquifer Using Geophysical Methods, Albert Yeboah-Forson

FIU Electronic Theses and Dissertations

The anisotropy of the Biscayne Aquifer which serves as the source of potable water for Miami-Dade County was investigated by applying geophysical methods. Electrical resistivity imaging, self potential and ground penetration radar techniques were employed in both regional and site specific studies. In the regional study, electrical anisotropy and resistivity variation with depth were investigated with azimuthal square array measurements at 13 sites. The observed coefficient of electrical anisotropy ranged from 1.01 to 1.36. The general direction of measured anisotropy is uniform for most sites and trends W-E or SE-NW irrespective of depth. Measured electrical properties were used to estimate …


Analyzing Tidal Fluctuations In The Big Pine Key Freshwater Lens With Time-Lapse Resistivity, Nicole M. Tucker May 2013

Analyzing Tidal Fluctuations In The Big Pine Key Freshwater Lens With Time-Lapse Resistivity, Nicole M. Tucker

FIU Electronic Theses and Dissertations

The tidal influence on the Big Pine Key saltwater/freshwater interface was analyzed using time-lapse electrical resistivity imaging and shallow well measurements. The transition zone at the saltwater/freshwater interface was measured over part of a tidal cycle along three profiles. The resistivity was converted to salinity by deriving a formation factor for the Miami Oolite. A SEAWAT model was created to attempt to recreate the field measurements and test previously established hydrogeologic parameters. The results imply that the tide only affects the groundwater within 20 to 30 m of the coast. The effect is small and caused by flooding from the …


Water Demand And Allocation In The Mara River Basin, Kenya/Tanzania In The Face Of Land Use Dynamics And Climate Variability, Shimelis B. Dessu Mar 2013

Water Demand And Allocation In The Mara River Basin, Kenya/Tanzania In The Face Of Land Use Dynamics And Climate Variability, Shimelis B. Dessu

FIU Electronic Theses and Dissertations

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and …


Comparison And Validation Of Tropical Rainfall Measuring Mission (Trmm) Rainfall Algorithms In Tropical Cyclones, Joseph P. Zagrodnik Nov 2012

Comparison And Validation Of Tropical Rainfall Measuring Mission (Trmm) Rainfall Algorithms In Tropical Cyclones, Joseph P. Zagrodnik

FIU Electronic Theses and Dissertations

Tropical Rainfall Measuring Mission (TRMM) rainfall retrieval algorithms are evaluated in tropical cyclones (TCs). Differences between the Precipitation Radar (PR) and TRMM Microwave Imager (TMI) retrievals are found to be related to the storm region (inner core vs. rainbands) and the convective nature of the precipitation as measured by radar reflectivity and ice scattering signature. In landfalling TCs, the algorithms perform differently depending on whether the rainfall is located over ocean, land, or coastal surfaces. Various statistical techniques are applied to quantify these differences and identify the discrepancies in rainfall detection and intensity. Ground validation is accomplished by comparing the …


Controls On Sensible Heat And Latent Energy Fluxes From A Short-Hydroperiod Florida Everglades Marsh, Jessica L. Schedlbauer, Steven F. Oberbauer, Gregory Starr, Kristine L. Jimenez Jan 2011

Controls On Sensible Heat And Latent Energy Fluxes From A Short-Hydroperiod Florida Everglades Marsh, Jessica L. Schedlbauer, Steven F. Oberbauer, Gregory Starr, Kristine L. Jimenez

FCE LTER Journal Articles

Little is known of energy balance in low latitude wetlands where there is a year-round growing season and a climate best defined by wet and dry seasons. The Florida Everglades is a highly managed and extensive subtropical wetland that exerts a substantial influence on the hydrology and climate of the south Florida region. However, the effects of seasonality and active water management on energy balance in the Everglades ecosystem are poorly understood. An eddy covariance and micrometeorological tower was established in a short-hydroperiod Everglades marsh to examine the dominant environmental controls on sensible heat (H) and latent energy …


Land Use And Climate Change Impacts On The Hydrology Of The Upper Mara River Basin, Kenya: Results Of A Modeling Study To Support Better Resource Management, Liya M. Mango, Assefa M. Melesse, Michael E. Mcclain, Daniel Gann, S. G. Setegen Aug 2010

Land Use And Climate Change Impacts On The Hydrology Of The Upper Mara River Basin, Kenya: Results Of A Modeling Study To Support Better Resource Management, Liya M. Mango, Assefa M. Melesse, Michael E. Mcclain, Daniel Gann, S. G. Setegen

GIS Center

Some of the most valued natural and cultural landscapes on Earth lie in river basins that are poorly gauged and have incomplete historical climate and runoff records. The Mara River Basin of East Africa is such a basin. It hosts the internationally renowned Mara-Serengeti landscape as well as a rich mixture of indigenous cultures. The Mara River is the sole source of surface water to the landscape during the dry season and periods of drought. During recent years, the flow of the Mara River has become increasingly erratic, especially in the upper reaches, and resource managers are hampered by a …


Flux Of Organic Carbon In A Riverine Mangrove Wetland In The Florida Coastal Everglades, Melissa M. Romigh, Stephen E. Davis Iii, Victor H. Rivera-Monroy, Robert R. Twilley Jan 2006

Flux Of Organic Carbon In A Riverine Mangrove Wetland In The Florida Coastal Everglades, Melissa M. Romigh, Stephen E. Davis Iii, Victor H. Rivera-Monroy, Robert R. Twilley

FCE LTER Journal Articles

Short-term (daily) and seasonal variations in concentration and flux of dissolved organic carbon (DOC) were examined over 15 tidal cycles in a riverine mangrove wetland along Shark River, Florida in 2003. Due to the influence of seasonal rainfall and wind patterns on Shark River’s hydrology, samplings were made to include wet, dry and transitional (Norte) seasons. We used a flume extending from a tidal creek to a basin forest to measure vertical (vegetated soil/water column) and horizontal (mangrove forest/tidal creek) flux of DOC. We found significant (p < 0.05) variations in surface water temperature, salinity, conductivity, pH and mean concentration of DOC with season. Water temperature and salinity followed seasonal patterns of air temperature and rainfall, while mean DOC concentration was highest during the dry season (May), followed by the wet (October) and ‘Norte’ (December) seasons. This pattern of DOC concentration may be due to a combination of litter production and inundation pattern of the wetland. In contrast to daily (between tides) variation in DOC flux between the mangrove forest and tidal creek, daily variations of mean water quality were not significant. However, within-tide variation of DOC flux, dissolved oxygen content and salinity was observed. This indicated that the length of inundation and water source (freshwater vs. saltwater) variation across tidal cycles influenced water quality and DOC flux in the water column. Net DOC export was measured in October and December, suggesting the mangrove forest was a source of DOC to the adjacent tidal creek during these periods. Net annual export of DOC from the fringe mangrove to both the tidal creek and basin mangrove forest was 56 g C m−2 year−1. The seasonal pattern in our flux results indicates …