View All Items

Title: Streamflow prediction in ungauged basins located within data-scarce regions.
Creator: Alipour, Mohammadhossein, Kibler, Kelly, Wang, Dingbao, Mayo, Talea, Emrich, Christopher, University of Central Florida
Abstract / Description: Preservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction...
Show morePreservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction in ungauged catchments located within large-scale regions of minimal hydrometeorologic observation. Multi-objective nature of SPED allows for balancing runoff efficiency with selection of parameter values that resemble catchment physical characteristics. Uncertain and low-resolution information are incorporated in SPED as soft data along with sparse observations. SPED application in two catchments in southwestern China indicates high runoff efficiency for predictions and good estimation of soil moisture capacity in the catchments. SPED is then slightly modified and tested more comprehensively by application to six catchments with diverse hydroclimatic conditions. SPED performance proves satisfactory where traditional flow prediction approaches fail. SPED also proves comparable or even better than data-intensive approaches. Utility of SPED versus a simpler catchment similarity model for the study of flow regime alteration is pursued next by streamflow prediction in 32 rivers in southwestern China. The results indicate that diversion adversely alters the flow regime of the rivers while direction and pattern of change remain the same regardless of the flow prediction method of choice. However, the results based on SPED consistently indicate more substantial alterations to the flow regime of the rivers after diversion. Finally, the value added by a limited number of streamflow observations to improvement of predictions in an ungauged catchment located within a data-scarce region is studied. The large number of test scenarios indicate that there may be very few near-universal schemes to improve flow predictions in such catchments.
Show less
Date Issued: 2019
Identifier: CFE0007426, ucf:52713
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007426

Title: DEVELOPMENT OF DAILY, MONTHLY, INTER-ANNUAL, AND MEAN ANNUAL HYDROLOGICAL MODELS BASED ON A UNIFIED RUNOFF GENERATION FRAMEWORK.
Creator: Kheimi, Marwan, Wang, Dingbao, Wahl, Thomas, Singh, Arvind, Zheng, Qipeng, University of Central Florida
Abstract / Description: The main goal of this dissertation develops a unified model structure for runoff generation based on observations from a large number of catchments. Furthermore, obtaining a comprehensive understanding of the physical controlling factors that control daily, monthly, and annual water balance models. Meanwhile, applying the developed Unified model on different climate conditions, and comparing it with different well-known models.The proposed model was compared with a similar timescale model ...
Show moreThe main goal of this dissertation develops a unified model structure for runoff generation based on observations from a large number of catchments. Furthermore, obtaining a comprehensive understanding of the physical controlling factors that control daily, monthly, and annual water balance models. Meanwhile, applying the developed Unified model on different climate conditions, and comparing it with different well-known models.The proposed model was compared with a similar timescale model (HyMOD, and abcd) and applied on 92 catchments from MOPEX dataset across the United States. The HyMOD and abcd are a well-known daily and monthly hydrological model used on a variety of researchers. The differences between the new model and HyMOD, and abcd include 1) the distribution function for soil water storage capacity is different and the new distribution function leads to the SCS curve number method; and 2) the computation of evaporation is also based on the distribution function considering the spatial variability of available water evaporation. The performance of all models along with parameters used is examined to understand the controlling factors. The generated results were calibrated and validated using the Nash-Sutcliffe efficiency coefficient (NSE), indicating that the Unified model has a moderate better performance against the HyMOD at a daily time scale, and abcd model at a monthly timescale. The proposed model using the SCS-CN method shows the effect of improving the performance.
Show less
Date Issued: 2019
Identifier: CFE0007478, ucf:52684
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007478

Title: Sinkhole detection and quantification using LiDAR data.
Creator: Rajabi, Amirarsalan, Nam, Boo Hyun, Wang, Dingbao, Singh, Arvind, University of Central Florida
Abstract / Description: The state of Florida is highly prone to sinkhole incident and formation, mainly because of the soluble carbonate bedrock which is susceptible to dissolution and groundwater recharge that causes internal soil erosions. Numerous sinkholes, particularly in Central Florida, have occurred. Florida Subsidence Incident Report (FSIR) database contains verified sinkholes with Global Positioning System (GPS) information. In addition to existing detection methods such as subsurface exploration and...
Show moreThe state of Florida is highly prone to sinkhole incident and formation, mainly because of the soluble carbonate bedrock which is susceptible to dissolution and groundwater recharge that causes internal soil erosions. Numerous sinkholes, particularly in Central Florida, have occurred. Florida Subsidence Incident Report (FSIR) database contains verified sinkholes with Global Positioning System (GPS) information. In addition to existing detection methods such as subsurface exploration and geophysical methods, a remote sensing method can be an alternative and efficient means to detect and characterize sinkholes with a wide coverage. the first part of this study is aimed at developing a method to detect sinkholes in Missouri by using Light Detection and Ranging (LiDAR) data. Morphometrical parameters such as TPI (Topographic Position Index), CI (Convergence Index), SI (Slope Index), and DEM (Digital Elevation Model) have a high potential to help detect sinkholes, based on local ground conditions and study area. The GLM (General Linear Model) built in R software is used to obtain morphometrical indices of the study terrain to be trained and build a logistic regression model to detect sinkholes. In the second part of the study, a semi-automated model in ArcMap is then developed to detect sinkholes and also to estimate geometric characteristics of sinkholes (e.g. depth, length, circularity, area, and volume). This remote sensing technique has a potential to detect unreported sinkholes in rural and/or inaccessible areas.
Show less
Date Issued: 2018
Identifier: CFE0007084, ucf:51992
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007084

Title: Assessing the Impact of Radionuclides Released into the Floridan Aquifer by a Massive Sinkhole on Local Municipal Water Supplies.
Creator: Arenas Daza, Maria, Duranceau, Steven, Sadmani, A H M Anwar, Wang, Dingbao, University of Central Florida
Abstract / Description: In late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW)...
Show moreIn late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW) production wells and two Polk County Utilities (PCU) water treatment facilities. Water samples collected between June 2017 and January 2018 at the TBW and PCU sites were found to contain radionuclides below regulated levels. To evaluate the effectiveness of membrane treatment should the TBW and PCU drinking water wells be affected by the spill in the future, bench-scale, flat-sheet reverse osmosis (RO) and nanofiltration (NF) membrane process testing was performed using TBW and PCU wellfield sample aliquots. NF and RO were shown to be capable of removing at minimum of 86 and 92 percent, respectively, of the barium content that had been spiked into groundwater testing aliquots. Based on testing results, a conceptual opinion of probable capital cost for a membrane process ranged from $1.7 and $3.5 million for a 0.25 MGD and 2.0 MGD design capacity, respectively. Process operation and maintenance costs ranged between $0.99/Kgal and $0.26/Kgal for a 0.25 MGD and 2.0 MGD design capacity, respectively. The amortized total cost based on a 20-year period and 8 percent interest rate ranged between $1.88/Kgal for a 0.25 MGD and $0.49/Kgal for a 2.0 MGD design capacity plant. An estimate of unavailable water value due to a long-term well shut-down was approximated as $0.64/Kgal.
Show less
Date Issued: 2018
Identifier: CFE0006970, ucf:52911
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006970

Title: Evaluating Hydrologic Fluxes Through Stormwater Treatment Systems: Implication to Freshwater Springs in a Karst Environment.
Creator: Rice, Nyle, Kibler, Kelly, Wang, Dingbao, Chang, Ni-bin, University of Central Florida
Abstract / Description: In recent years, concentrations of nutrients such as nitrogen and phosphorus have increased in surface and groundwater resources, due in part to non-point source pollution associated with stormwater runoff. The elevated nutrient concentrations found in stormwater runoff have prompted the design of best management practices (BMP's) to mitigate the problem. The overall objective within this thesis is to analyze the performance of innovative surface BMPs and investigate connections between the...
Show moreIn recent years, concentrations of nutrients such as nitrogen and phosphorus have increased in surface and groundwater resources, due in part to non-point source pollution associated with stormwater runoff. The elevated nutrient concentrations found in stormwater runoff have prompted the design of best management practices (BMP's) to mitigate the problem. The overall objective within this thesis is to analyze the performance of innovative surface BMPs and investigate connections between the BMPs and groundwater flows to freshwater springs within a karst environment. The performance of two stormwater BMPs, blanket filters and vertical reactors containing Bio-sorption Activated Media (BAM), are assessed in terms of hydraulic retention time. Capture efficiency is also evaluated for the blanket filters. Blanket filters captured, at minimum 68% of the stormwater runoff entering a stormwater basin in one year. Water content monitoring indicates that BAM is affected by the surrounding water table. The vertical reactors are more appropriate technologies for small contributing areas. Tracking a conservative tracer from an injection point within a stormwater basin to nearby Silver Springs reveals several unique flowpaths and velocities of groundwater. Subsurface velocities observed in the basin ranged from 0.1 m/d to 1.4 m/d, while velocities from the injection well to the spring vary from 2.3 m/d to 13.5 m/d. The fastest travel times observed in the spring may represent flowpaths that include macropore/conduit flow through karst features, while the slower peaks may be more representative of matrix flow. Interaction with karst features may reduce retention time of stormwater in aquifers, altering expected nutrient transformations. Understanding the variable pathways stormwater may take from the surface to spring discharge may assist environmental managers in preserving water quality in springs and other waterbodies in karst systems.
Show less
Date Issued: 2018
Identifier: CFE0007241, ucf:52219
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007241

Title: Frames and Phase Retrieval.
Creator: Juste, Ted, Han, Deguang, Sun, Qiyu, Dutkay, Dorin, Wang, Dingbao, University of Central Florida
Abstract / Description: Phase retrieval tackles the problem of recovering a signal after loss of phase. The phase problem shows up in many different settings such as X-ray crystallography, speech recognition, quantum information theory, and coherent diffraction imaging. In this dissertation we present some results relating to three topics on phase retrieval. Chapters 1 and 2 contain the relevant background materials. In chapter 3, we introduce the notion of exact phase-retrievable frames as a way of measuring aframe...
Show morePhase retrieval tackles the problem of recovering a signal after loss of phase. The phase problem shows up in many different settings such as X-ray crystallography, speech recognition, quantum information theory, and coherent diffraction imaging. In this dissertation we present some results relating to three topics on phase retrieval. Chapters 1 and 2 contain the relevant background materials. In chapter 3, we introduce the notion of exact phase-retrievable frames as a way of measuring aframe's redundancy with respect to its phase retrieval property. We show that, in the d-dimensional real Hilbert space case, exact phase-retrievable frames can be of any lengths between 2d ? 1 and d(d + 1)/2, inclusive. The complex Hilbert space case remains open.In chapter 4, we investigate phase-retrievability by studying maximal phase-retrievable subspaces with respect to a given frame. These maximal PR-subspaces can have different dimensions. We are able to identify the ones with the largest dimension and this can be considered as a generalizationof the characterization of real phase-retrievable frames. In the basis case, we prove that if M is a k-dimensional PR-subspace then |supp(x)| ? k for every nonzero vector x ? M . Moreover, if1 ? k (<) [(d + 1)/2], then a k-dimensional PR-subspace is maximal if and only if there exists a vector x ? M such that |supp(x)| = k.Chapter 5 is devoted to investigating phase-retrievable operator-valued frames. We obtain some characterizations of phase-retrievable frames for general operator systems acting on both finite and infinite dimensional Hilbert spaces; thus generalizing known results for vector-valued frames, fusion frames, and frames of Hermitian matrices.Finally, in Chapter 6, we consider the problem of characterizing projective representations that admit frame vectors with the maximal span property, a property that allows for an algebraic recov-ering of the phase-retrieval problem. We prove that every irreducible projective representation of a finite abelian group admits a frame vector with the maximal span property. All such vectors can be explicitly characterized. These generalize some of the recent results about phase-retrieval with Gabor (or STFT) measurements.
Show less
Date Issued: 2019
Identifier: CFE0007660, ucf:52503
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007660

Title: Influence of Topographic Elevation Error On Modeled Storm Surge.
Creator: Bilskie, Matthew, Hagen, Scott, Wang, Dingbao, Chopra, Manoj, University of Central Florida
Abstract / Description: The following presents a method for determining topographic elevation error for overland unstructured finite element meshes derived from bare earth LiDAR for use in a shallow water equations model. This thesis investigates the development of an optimal interpolation method to produce minimal error for a given element size. In hydrodynamic studies, it is vital to represent the floodplain as accurately as possible since terrain is a critical factor that influences water flow. An essential step...
Show moreThe following presents a method for determining topographic elevation error for overland unstructured finite element meshes derived from bare earth LiDAR for use in a shallow water equations model. This thesis investigates the development of an optimal interpolation method to produce minimal error for a given element size. In hydrodynamic studies, it is vital to represent the floodplain as accurately as possible since terrain is a critical factor that influences water flow. An essential step in the development of a coastal inundation model is processing and resampling dense bare earth LiDAR to a DEM and ultimately to the mesh nodes; however, it is crucial that the correct DEM grid size and interpolation method be employed for an accurate representation of the terrain. The following research serves two purposes: 1) to assess the resolution and interpolation scheme of bare earth LiDAR data points in terms of its ability to describe the bare earth topography and its subsequent performance during relevant tide and storm surge simulations.
Show less
Date Issued: 2012
Identifier: CFE0004520, ucf:49265
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004520

Title: Modeling Annual Water Balance in The Seasonal Budyko Framework.
Creator: Alimohammadi, Negin, Wang, Dingbao, Hagen, Scott, Madani Larijani, Kaveh, University of Central Florida
Abstract / Description: In this thesis, the role of soil water storage change on the annual water balance is evaluated based on observations at a large number of watersheds located in a spectrum of climate regions, and an annual water balance model is developed at the seasonal scale based on Budyko hypthesis. The annual water storage change is quantified based on water balance closure given the available data of precipitation, runoff, and evaporation estimated from remote sensing data and meteorology reanalysis. The...
Show moreIn this thesis, the role of soil water storage change on the annual water balance is evaluated based on observations at a large number of watersheds located in a spectrum of climate regions, and an annual water balance model is developed at the seasonal scale based on Budyko hypthesis. The annual water storage change is quantified based on water balance closure given the available data of precipitation, runoff, and evaporation estimated from remote sensing data and meteorology reanalysis. The responses of annual runoff, evaporation, and storage change to the interannual variability of precipitation and potential evaporation are then analyzed. Both runoff and evaporation sensitivities to potential evaporation are higher under energy-limited conditions, but storage change seems to be more sensitive to potential evaporation under the conditions in which water and energy are balanced. Runoff sensitivity to precipitation is higher under energy-limited conditions; but both evaporation and storage change sensitivities to precipitation are higher under water-limited conditions. Therefore, under energy-limited conditions, most of precipitation variability is transferred to runoff variability; but under water-limited conditions, most of precipitation variability is transferred to storage change and some of precipitation variability is transferred to evaporation variability. The main finding of this part is that evaporation variability will be overestimated by assuming negligible storage change in annual water balance, particularly under water-limited conditions. Budyko framework which expresses partitioning of water supply at the mean annual scale, is adapted to be applicable in modeling water cycle in short terms i.e., seasonal and interannual scales. Seasonal aridity index is defined as the ratio of seasonal potential evaporation and the difference between precipitation and storage change. The seasonal water balance is modeled by using a Budyko-type curve with horizontal shifts which leads prediction of seasonal and annual storage changes and evaporation if precipitation, potential evaporation, and runoff data are available.
Show less
Date Issued: 2012
Identifier: CFE0004509, ucf:49283
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004509

Title: State (Hydrodynamics) Identification in the Lower St. Johns River using the Ensemble Kalman filter.
Creator: Tamura, Hitoshi, Hagen, Scott, Wang, Dingbao, Bacopoulos, Peter, University of Central Florida
Abstract / Description: This thesis presents a method, Ensemble Kalman Filter (EnKF), applied to a high-resolution, shallow water equations model (DG ADCIRC-2DDI) of the Lower St. Johns River with observation data at four gauging stations. EnKF, a sequential data assimilation method for non-linear problems, is developed for tidal flow simulation for estimation of state variables, i.e., water levels and depth-integrated currents for overland unstructured finite element meshes. The shallow water equations model is...
Show moreThis thesis presents a method, Ensemble Kalman Filter (EnKF), applied to a high-resolution, shallow water equations model (DG ADCIRC-2DDI) of the Lower St. Johns River with observation data at four gauging stations. EnKF, a sequential data assimilation method for non-linear problems, is developed for tidal flow simulation for estimation of state variables, i.e., water levels and depth-integrated currents for overland unstructured finite element meshes. The shallow water equations model is combined with observation data, which provides the basis of the EnKF applications. In this thesis, EnKF is incorporated into DG ADCIRC-2DDI code to estimate the state variables.Upon its development, DG ADCIRC-2DDI with EnKF is first validated by implementing to a low-resolution, shallow water equations model of a quarter annular harbor with synthetic observation data at six gauging stations. Second, DG ADCIRC-2DDI with EnKF is implemented to a high-resolution, shallow water equations model of the Lower St. Johns River with real observation data at four gauging stations. Third, four different experiments are performed by applying DG ADCIRC-2DDI with EnKF to the Lower St. Johns River.
Show less
Date Issued: 2012
Identifier: CFE0004331, ucf:49455
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004331

Title: Comparison of a modified and traditional rapid infiltration basin for treatment and control of nutrients in wastewater effluent.
Creator: Cormier, Jessica, Duranceau, Steven, Wang, Dingbao, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Rapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water...
Show moreRapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water disposal. Few, if any, studies have been published where BAM-modified RIBs have been used for this purpose. In this work, a mixture of clay, tire crumb, and sand (CTS) was selected to serve as the BAM material (Bold and Gold(TM) CTS media). Each RIB was constructed with two feet of either sand or BAM, covering more than 43,600 square feet of surface area. The BAM-modified RIB had an initial 90 pounds per cubic-foot in-place density, and the density of the control RIB approximated about 94 pounds per cubic-foot. Over an eight-month period, loadings to the BAM RIB and control RIB approximated 5.4 million gallons (MG) per acre each. Water samples, collected from lysimeters installed below the 2-foot of sand or BAM materials, were gathered monthly during 2017 (except for September and October due to the impacts of hurricane Irma); these samples were analyzed for water quality to determine nitrate removal. Soil moisture and weather data were also collected over the study period. This study demonstrated the nitrate removal effectiveness of a field-scale BAM-modified RIB as compared to a traditional field-scale sand-based RIB. Results suggest that BAM removed 30 percent more nitrates than the Control (78% and 47%, respectively) under the conditions of the study. Furthermore, BAM removed higher percentages of TN (31%) and TP (62%) than the Control (12% and 28%, respectively).
Show less
Date Issued: 2018
Identifier: CFE0007566, ucf:52583
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007566

Title: Site Specific Sinkhole risk assessment in Central Florida using Cone Penetration Testing.
Creator: Shamet, Ryan, Nam, Boo Hyun, Chopra, Manoj, Wang, Dingbao, University of Central Florida
Abstract / Description: As Florida's population is expanding and greater fluctuations in groundwater levels are being recorded, Central Florida has been experiencing a higher frequency of sinkhole occurrences than ever before in recorded history. Sinkholes in Central Florida are formed by a combination of bedrock weathering and overburden soil erosion due to the groundwater recharge and are a part of Florida's past and future geology. The initial stage of a sinkhole is referred to as soil raveling and is the most...
Show moreAs Florida's population is expanding and greater fluctuations in groundwater levels are being recorded, Central Florida has been experiencing a higher frequency of sinkhole occurrences than ever before in recorded history. Sinkholes in Central Florida are formed by a combination of bedrock weathering and overburden soil erosion due to the groundwater recharge and are a part of Florida's past and future geology. The initial stage of a sinkhole is referred to as soil raveling and is the most effective time to perform soil improvement measures, such as grouting, to mitigate further expansion of a subterranean void. Subsurface exploration tests, commonly implemented by geotechnical engineers for site characterization, have been shown to detect these sinkhole anomalies even when no signs of subsidence are evident on the ground surface. Secondary geophysical testing has also been proven to detect sinkhole raveling anomalies, but at the expense of additional time and money added to the specific project. In this study, current practices in detecting premature sinkholes were expanded upon with a primary focus on Cone Penetrometer testing data (CPT). Cone Penetrometer tests provide valuable high-resolution quantitative information regarding the discrete strength characteristics of relatively loose sandy and clayey subsoil. CPTs are also much quicker and cleaner to perform when compared to other subsurface testing procedures (e.g. Standard penetration tests). Therefore, CPTs were chosen for this study to understand how they can be implemented to assess risk of future sinkhole collapse, or other karst construction concerns, in Central Florida specific soils. By implementing the findings presented in this report, Geotechnical engineers and contractors in central Florida will be able to practically evaluate the size and severity of potential forming sinkhole without the use of additional subsurface geophysical testing. The results of this study hope to eliminate extraneous testing costs, as well as maximize the efficiency of estimating mitigation products and procedures required all while still ensuring a safe design in Central Florida's highly karst areas.
Show less
Date Issued: 2017
Identifier: CFE0006657, ucf:51246
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006657

Title: Tidal hydrodynamic response to sea level rise and coastal geomorphology in the Northern Gulf of Mexico.
Creator: Passeri, Davina, Hagen, Scott, Medeiros, Stephen, Wang, Dingbao, Weishampel, John, University of Central Florida
Abstract / Description: Sea level rise (SLR) has the potential to affect coastal environments in a multitude of ways, including submergence, increased flooding, and increased shoreline erosion. Low-lying coastal environments such as the Northern Gulf of Mexico (NGOM) are particularly vulnerable to the effects of SLR, which may have serious consequences for coastal communities as well as ecologically and economically significant estuaries. Evaluating potential changes in tidal hydrodynamics under SLR is essential for...
Show moreSea level rise (SLR) has the potential to affect coastal environments in a multitude of ways, including submergence, increased flooding, and increased shoreline erosion. Low-lying coastal environments such as the Northern Gulf of Mexico (NGOM) are particularly vulnerable to the effects of SLR, which may have serious consequences for coastal communities as well as ecologically and economically significant estuaries. Evaluating potential changes in tidal hydrodynamics under SLR is essential for understanding impacts to navigation, ecological habitats, infrastructure and the morphologic evolution of the coastline. The intent of this research is to evaluate the dynamic effects of SLR and coastal geomorphology on tidal hydrodynamics along the NGOM and within three National Estuarine Research Reserves (NERRs), namely Grand Bay, MS, Weeks Bay, AL, and Apalachicola, FL. An extensive literature review examined the integrated dynamic effects of SLR on low gradient coastal landscapes, primarily in the context of hydrodynamics, coastal morphology, and marsh ecology. Despite knowledge of the dynamic nature of coastal systems, many studies have neglected to consider the nonlinear effects of SLR and employed a simplistic (")bathtub(") approach in SLR assessments. More recent efforts have begun to consider the dynamic effects of SLR (e.g., the nonlinear response of hydrodynamics under SLR); however, little research has considered the integrated feedback mechanisms and co-evolution of multiple interdependent systems (e.g., the nonlinear responses and interactions of hydrodynamics and coastal morphology under SLR). Synergetic approaches that integrate the dynamic interactions between physical and ecological environments will allow for more comprehensive evaluations of the impacts of SLR on coastal systems.Projecting future morphology is a challenging task; various conceptual models and statistical methods have been employed to project future shoreline positions. Projected shoreline change rates from a conceptual model were compared with historic shoreline change rates from two databases along sandy shorelines of the. South Atlantic Bight and NGOM coasts. The intent was not to regard one method as superior to another, but rather to explore similarities and differences between the methods and offer suggestions for projecting shoreline changes in SLR assessments.The influence of incorporating future shoreline changes into hydrodynamic modeling assessments of SLR was evaluated for the NGOM coast. Astronomic tides and hurricane storm surge were simulated under present conditions, the projected 2050 sea level with present-day shorelines, and the projected 2050 sea level with projected 2050 shorelines. Results demonstrated that incorporating shoreline changes had variable impacts on the hydrodynamics; storm surge was more sensitive to the shoreline changes than astronomic tides. It was concluded that estimates of shoreline change should be included in hydrodynamic assessments of SLR along the NGOM. Evaluating how hydrodynamics have been altered historically under a changing landscape in conjunction with SLR can provide insight to future changes. The Grand Bay estuary has undergone significant landscape changes historically. Tidal hydrodynamics were simulated for present and historic conditions (dating back to 1848) using a hydrodynamic model modified with unique sea levels, bathymetry, topography, and shorelines representative of each time period. Changes in tidal amplitudes varied across the domain. Harmonic constituent phases sped up from historic conditions. Tidal velocities in the estuary were stronger historically, and reversed from being flood dominant in 1848 to ebb dominant in 2005. To project how tidal hydrodynamics may be altered under future scenarios along the NGOM and within the three NERRs, a hydrodynamic model was used to simulate present (circa 2005) and future (circa 2050 and 2100) astronomic tides. The model was modified with projections of future sea levels as well as shoreline positions and dune elevations obtained from a Bayesian network (BN) model. Tidal amplitudes within some of the embayments increased under the higher SLR scenarios; there was a high correlation between the change in the inlet cross-sectional area under SLR and the change in the tidal amplitude within each bay. Changes in harmonic constituent phases indicated faster tidal propagation in the future scenarios within most of the bays. Tidal velocities increased in all of the NERRs which altered flood and ebb current strengths.The work presented herein improves the understanding of the response of tidal hydrodynamics to morphology and SLR. This is beneficial not only to the scientific community, but also to the management and policy community. These findings will have synergistic effects with a variety of coastal studies including storm surge and biological assessments of SLR. In addition, findings can benefit monitoring and restoration activities in the NERRs. Ultimately, outcomes will allow coastal managers and policy makers to make more informed decisions that address specific needs and vulnerabilities of each particular estuary, the NGOM coastal system, and estuaries elsewhere with similar conditions.
Show less
Date Issued: 2015
Identifier: CFE0006049, ucf:50962
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006049

Title: Development of an Automated Method for Identification of Wet and Dry Channel Segments Using LiDAR Data and Fuzzy Logic Cluster Analysis.
Creator: Rowney, Chris, Wang, Dingbao, Medeiros, Stephen, Kibler, Kelly, University of Central Florida
Abstract / Description: Research into the use of LiDAR data for purposes other than simple topographic elevation determination, such as urban land cover classification and the identification of forest biomass, has become prominent in recent years. In many cases, alternative analysis methodologies conducted using airborne LiDAR data are possible because the raw data collected during a survey can include information other than the classically used elevation and coordinate points, the X, Y, and Z of the plane. In...
Show moreResearch into the use of LiDAR data for purposes other than simple topographic elevation determination, such as urban land cover classification and the identification of forest biomass, has become prominent in recent years. In many cases, alternative analysis methodologies conducted using airborne LiDAR data are possible because the raw data collected during a survey can include information other than the classically used elevation and coordinate points, the X, Y, and Z of the plane. In particular, intensity return values for each point in a LiDAR grid have been found to provide a useful data set for wet and dry channel classification. LiDAR intensity return data are, in essence, a numeric representation of the characteristic light reflectivity of the object being scanned; the more reflective the object is, the higher the intensity return will be. Intensity data points are collected along the course of the channel network and within the perceived banks of the channel. Intensity data do not crisply reflect a perfectly wet or dry condition, but instead vary over a range such that each location can be viewed as partially wet and partially dry. It is advantageous to assess problems of this type using the methods of fuzzy logic. Specifically, the variance in LiDAR intensity return data is such that the use of fuzzy logic to identify intensity cluster centers, and thereby assign wet and dry condition identifiers based on fuzzy memberships, is a possibility. Membership within a fuzzy data set is characterized by a value representing the degree of membership. Typically, membership values range from 0 (representing non-membership) through 1 (representing full membership), with many observations found to be not at either extreme but instead at some intermediate value representing partial membership. The ultimate goal of this research was to design and develop an automated algorithm to identify wet and dry channel sections, given a previously identified channel network based on topographic elevation, using a combination of intensity return values from LiDAR data and fuzzy logic clustering methods, and to implement that algorithm in such a way as to produce reliable multi-class channel segments in ArcGIS. To enable control of calculations, limiting parameters were defined, specifically including the maximum allowable bank slope, and a filtering percentage to more accurately accommodate the study area.Alteration of the maximum allowable bank slope has been shown to affect the comparative quantity of high and low intensity centroids, but only in extreme bank slope conditions are the centroids changed enough to hamper results. However, interference from thick vegetation has been shown to lower intensity values in dry channel sections into the range of a wet channel. The addition of a filtering algorithm alleviates some of the interference, but not all. Overall results of the tool show an effective methodology where basic channel conditions are identified, but refinement of the tool could produce more accurate results.
Show less
Date Issued: 2015
Identifier: CFE0006053, ucf:50975
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006053

Title: Hydromorphology of the Econlockhatchee River.
Creator: Baker, John, Wang, Dingbao, Hagen, Scott, Chopra, Manoj, University of Central Florida
Abstract / Description: Climate change and human activities alter the hydrologic systems and exerted global scale impacts on our environment with significant implications for water resources. Climate change can be characterized by the change of precipitation and temperature, and both precipitation pattern change and global warming are associated with the increase in frequency of flooding or drought and low flows. With increasing water demand from domestic, agricultural, commercial, and industrial sectors, humans are...
Show moreClimate change and human activities alter the hydrologic systems and exerted global scale impacts on our environment with significant implications for water resources. Climate change can be characterized by the change of precipitation and temperature, and both precipitation pattern change and global warming are associated with the increase in frequency of flooding or drought and low flows. With increasing water demand from domestic, agricultural, commercial, and industrial sectors, humans are increasingly becoming a significant component of the hydrologic cycle. Human activities have transformed hydrologic processes at spatial scales ranging from local to global. Human activities affecting watershed hydrology include land use change, dam construction and reservoir operation, groundwater pumping, surface water withdrawal, irrigation, return flow, and others. In this thesis, the hydromorphology (i.e., the change of coupled hydrologic and human systems) of the Econlockhatchee River (Econ River for short) is studied. Due to the growth of the Orlando metropolitan area the Econ basin has been substantially urbanized with drastic change of the land cover. The land use / land cover change from 1940s to 2000s has been quantified by compiling existing land cover data and digitizing aerial photography images. Rainfall data have been analyzed to determine the extent that climate change has affected the river flow compared to land use change. The changes in stream flow at the annual scale and low flows are analyzed. The Econ River has experienced minimal changes in the amount of annual streamflow but significant changes to the amount of low flows. These changes are due to urbanization and other human interferences.
Show less
Date Issued: 2013
Identifier: CFE0005126, ucf:50692
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005126

Title: A Continuous Hydrologic Model Structure for Applications at Multiple Time Scales.
Creator: Griffen, Jonathan, Wang, Dingbao, O'Reilly, Andrew, Medeiros, Stephen, University of Central Florida
Abstract / Description: There are many different controlling factors on the partitioning of rainfall into runoff. However, the influence of each of these controls varies across different temporal scales. Consequently, numerous water balance models have been developed in the literature for application across various time scales. These models are usually developed for a particular time scale so that the controls with the greatest influence on rainfall partitioning are captured. For example, the SCS curve number method...
Show moreThere are many different controlling factors on the partitioning of rainfall into runoff. However, the influence of each of these controls varies across different temporal scales. Consequently, numerous water balance models have been developed in the literature for application across various time scales. These models are usually developed for a particular time scale so that the controls with the greatest influence on rainfall partitioning are captured. For example, the SCS curve number method was developed to simulate direct runoff at the event scale; the (")abcd(") model was developed as a monthly water balance model; and the Budyko model was developed for long-term water balance. More recently, the proportionality hypothesis, which traces its origins from the SCS curve number method, has been identified as the commonality between these three hydrologic models, suggesting that this hypothesis may be the unifying principle of hydrologic models across various time scales.The objective of this thesis is to develop a conceptual hydrologic model structure for continuous simulations for multiple time scales. The developed model is applicable to daily, monthly, and annual time scales.Direct runoff is computed by a proportionality relationship in the SCS curve number method. In the (")abcd(") model, evapotranspiration and storage at the end of each time period are computed by a proportionality relationship, however evapotranspiration is computed based on an exponential relationship of storage and potential evapotranspiration while base flow is computed based on a linear reservoir model. In the Budyko model, runoff and evapotranspiration are computed by a proportionality relationship.The primary difference with the proposed model in this thesis in comparison with the other three water balance models is the application of the proportionality hypothesis to the partitioning of surface runoff and continuing abstraction as well as the partitioning of continuing evapotranspiration and subsurface flow.The proposed model structure is implemented in Matlab. The developed model includes six parameters, which are estimated for 71 case study catchments in the United States using a genetic algorithm. The model performances at the daily, monthly and annual time scales are evaluated during calibration and validation periods, and compared with the (")abcd(") model and a Budyko-type model developed for multiple time scales.Evaluation of the models shows that the proposed model performs better or comparable to the other models at all time scales.
Show less
Date Issued: 2014
Identifier: CFE0005173, ucf:50672
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005173

Title: Response of Streamflow and Sediment Loading in the Apalachicola River, Florida to Climate and Land Use Land Cover Change.
Creator: Hovenga, Paige, Medeiros, Stephen, Wang, Dingbao, Kibler, Kelly, University of Central Florida
Abstract / Description: Located in Florida's panhandle, the Apalachicola River is the southernmost reach of the Apalachicola-Chattahoochee-Flint (ACF) River basin. Streamflow and sediment drains to Apalachicola Bay in the Northern Gulf of Mexico, directly influencing the ecology of the region, in particular seagrass and oyster production. The objective of this study is to evaluate the response of runoff and sediment loading in the Apalachicola River under projected climate change scenarios and land use / land cover ...
Show moreLocated in Florida's panhandle, the Apalachicola River is the southernmost reach of the Apalachicola-Chattahoochee-Flint (ACF) River basin. Streamflow and sediment drains to Apalachicola Bay in the Northern Gulf of Mexico, directly influencing the ecology of the region, in particular seagrass and oyster production. The objective of this study is to evaluate the response of runoff and sediment loading in the Apalachicola River under projected climate change scenarios and land use / land cover (LULC) change. A hydrologic model using the Soil Water Assessment Tool (SWAT) was developed for the Apalachicola region to simulate daily discharge and sediment load under present (circa 2000) and future conditions (circa 2100) to understand how the system responds over seasonal and event time frames to changes in climate, LULC, and coupled climate / LULC. These physically-based models incorporate a digital elevation model (DEM), LULC, soil maps, climate data, and management controls. Long Ashton Research Station-Weather Generator (LARS-WG) was used to create downscaled stochastic temperature and precipitation inputs from three Global Climate Models (GCM), each under Intergovernmental Panel on Climate Change (IPCC) carbon emission scenarios for A1B, A2, and B1. Projected 2100 LULC data provided by the United States Geological Survey (USGS) EROS Center was incorporated for each corresponding IPCC scenario. Results indicate climate change may induce seasonal shifts to both runoff and sediment loading, acting to extend periods of high flow and minimum sediment loadings or altering the time at which these events occur completely. Changes in LULC showed minimal effects on flow while more sediment loading was associated with increased agriculture and urban areas and decreased forested regions. A nonlinear response for both streamflow and sediment loading was observed by coupling climate and LULC change into the hydrologic model, indicating changes in one may exacerbate or dampen the effects of the other. Peak discharge and sediment loading associated with extreme events showed both increases and decreases in the future, with variability dependent on the GCM used. Similar behavior was observed in the total discharge resulting from extreme events and increased total sediment load was frequently predicted for the A2 and A1B scenarios for simulations involving changes in climate only, LULC only, and both climate and LULC. Output from the individual GCMs predicted differing responses of streamflow and sediment loading to changes in climate on both the seasonal and event scale. Additional region-specific research is needed to better optimize the GCM ensemble and eliminate those that provide erroneous output. In addition, future assessment of the downscaling approach to capture extreme events is required. Findings from this study can be used to further understand climate and LULC implications to the Apalachicola Bay and surrounding region as well as similar fluvial estuaries while providing tools to better guide management and mitigation practices.
Show less
Date Issued: 2015
Identifier: CFE0006326, ucf:51543
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006326

Title: Bioremediation of a Trichloroethene DNAPL Source Zone Utilizing a Partitioning Electron Donor - Field Implementation.
Creator: Bartlett, Joseph, Randall, Andrew, Reinhart, Debra, Wang, Dingbao, Daprato, Rebecca, University of Central Florida
Abstract / Description: Trichloroethene (TCE) is a chlorinated volatile organic compound (CVOC) that can be found in industrial and household products. It is typically used as a solvent or degreaser. TCE can have detrimental health impacts and is known to be carcinogenic to humans. Federal and state regulatory drivers determine the need to assess and remediate soil and groundwater contaminated with CVOCs. There are many different methods for remediation; however, bioremediation has the ability to breakdown TCE all...
Show moreTrichloroethene (TCE) is a chlorinated volatile organic compound (CVOC) that can be found in industrial and household products. It is typically used as a solvent or degreaser. TCE can have detrimental health impacts and is known to be carcinogenic to humans. Federal and state regulatory drivers determine the need to assess and remediate soil and groundwater contaminated with CVOCs. There are many different methods for remediation; however, bioremediation has the ability to breakdown TCE all the way to harmless gasses (ethene and ethane). Bioremediation requires dechlorinating microbes (indigenous or augmented), electron donor (food source), and an electron acceptor (CVOCs). Electron donors are typically injected into the target area and are distributed naturally throughout the subsurface. A partitioning electron donor (PED) has the ability to partition from the dissolved phase into low permeability zones and/or dense non-aqueous phase liquids (DNAPLs) (i.e. source zones), and then be slowly released and readily metabolized at the DNAPL:water interface. This thesis summarizes the first field scale PED implementation with the main research objective of evaluating whether utilizing a PED for bioremediation of a TCE source zone is achievable. Based on laboratory studies, n-butyl acetate (nBA) was selected as the PED for application in a TCE source area, selected at Cape Canaveral Air Force Station's Launch Complex 34, identified as Hot Spot 1. Hot Spot 1 has a zone of high concentration TCE in a low permeability clay layer at a depth of approximately 40 feet below land surface (ft BLS). Implementation included the recirculation of groundwater above and below the clay layer without PED injection for comparative analysis (baseline flux), then with PED injection in, above, and below the clay layer (system operation phase). The groundwater was recirculated using a solar powered recirculation system, which consisted of a pair of extraction wells in the center of the treatment area, screened above and below the low permeability layer, and a set of five peripheral injection well pairs, similarly screened, used to create an inward hydraulic gradient and promote horizontal flow across the top and base of the clay layer. Groundwater concentrations in the treatment area were monitored using three monitoring well clusters (each with six depth intervals ranging from 23 to 61 ft BLS) and existing monitoring wells in the treatment area. The groundwater recirculation system was operated, without addition of PED, for approximately four weeks to establish the baseline flux condition. PED was then introduced to the subsurface by injecting 34,000 gallons of a solution containing nBA (3,000 mg/L) and conservative tracers (bromide and/or iodide) using direct push technology (DPT) at 20 locations from approximately 23 to 62 ft BLS. Confirmation sampling (DPT groundwater and monitoring well sampling) was conducted to assess the PED distribution after injection activities. The recirculation system remained off after PED injection for approximately four weeks to allow the PED to partition into the DNAPL and to facilitate the acclimation and establishment of biomass within the treatment area. The recirculation system was then restarted and operated for approximately one year. Groundwater sampling was performed regularly to assess mass flux and microbial reductive dechlorination. PED amendment was successfully injected above, in, and below the low permeability layer, as evidenced by positive detections of nBA from soil and groundwater sampling within the treatment area immediately following the injection event. The implementation was also successful in reducing contaminant mass from both soil and groundwater.CVOC mass removed during the baseline flux phase (pre-PED injection; 14 March 2011 to 18 April 2011) was calculated based on groundwater sampling data and totaled 14 pounds (lbs). All of the mass removed during the baseline flux phase was from the high permeability layer, indicating that mass removed was dissolved phase mass above and below the clay layer. Mass removal was likely a result of extraction and dilution from operation of the recirculation system. The mass removal rate during the baseline flux phase was approximately 0.40 pounds per day (lbs/day).CVOC mass removed during the system operation phase (post-PED injection; 9 August 2011 to 11 September 2012) was calculated based on groundwater and soil sampling data and totaled 110 lbs. Of the 110 lbs removed, 78 lbs of CVOC mass was removed from the high permeability layer and 32 lbs was removed from the low permeability layer, indicating that not only dissolved phase mass in the high permeability layer was removed, but source zone material sorbed into the low permeability layer was removed as well. Mass removed from the low permeability layer was likely a result degredation (ie. reductive dechlorination) at and around the DNAPL:water interface. The mass removal rate during the system operation phase was approximately 0.28 lbs/day. The higher rate of removal during the baseline flux phase is likely due to the initial removal of a significant amount of dissolved phase CVOCs and not the mass sorbed into the low permeability layer.In general, TCE and cis-1,2-dichloroethene (cDCE) concentrations decreased during the baseline flux phase with no increase in vinyl chloride (VC) concentration, indicating removal via extraction and dilution and not reductive dechlorination. Following the PED injection, TCE and cDCE concentrations generally decreased with increases observed in VC concentrations, indicative of reductive dechlorination. Ethene concentration was monitored to assess complete dechlorination from TCE to ethene. Average ethene concentration detected in samples collected from treatment zone monitoring wells increased from 52.8 micrograms per liter (?g/L) (pre-injection; April 2011) to 408 ?g/L (September 2012), indicating complete dechlorination of CVOCs was occurring. In addition, dechlorinating microbial biomass increased significantly, as evidenced by increases in average Dhc (dechlorinating microbial culture) and vcrA (specific gene of culture responsible for breaking down VC through to ethene) concentrations detected in samples collected from treatment zone monitoring wells; Dhc increased from 8.5x106 gene copies/L (pre-injection; April 2011) to 5.0x107 gene copies/L (September 2012) and vcrA increased from 5.0x103 gene copies/L (April 2011) to 6.8x107 gene copies/L (September 2012).TOC concentration was shown to generally increase following the injection activities, then decrease through the system operation period, indicating the electron donor was successfully injected into the subsurface, and was being utilized by the indigenous dechlorinating microbial population. Remaining TOC at the site was minimal, with an average TOC concentration of 21 mg/L (September 2012) detected in samples collected from treatment zone monitoring wells, decreasing from 250 mg/L (August 2011) just following injection. If reductive dechlorination were to continue to occur, more electron donor would be needed.The reduction of CVOC concentrations at the site are likely due to reductive dechlorination as a result of the PED amendment injection, as evidenced by: (i) the production of daughter products relative to the degradation of TCE; (ii) the production of ethene; (iii) the production of dechlorinating microbial mass; and (iv) the reduction of electron donor.Although effective, nBA was utilized and depleted quicker than an industry electron donor would be expected to last, depleting within 12 months, as opposed to two to three years. Based on this alone, it appears that nBA would not be a good candidate for full scale implementation at this or other sites; however, to provide a true comparative analysis, side-by-side test plots would be recommended at the site, one utilizing nBA and one utilizing a standard substrate. This would ensure both electron donor options are being subjected to the same geophysical and geochemical settings and the same or similar contaminant concentrations.
Show less
Date Issued: 2016
Identifier: CFE0006439, ucf:51457
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006439

Title: Transforming the Aquatic Urban Landscape: Nutrient Status and Management of Stormwater Basins.
Creator: Skovira, Lindsay, Bohlen, Patrick, Fauth, John, Wang, Dingbao, University of Central Florida
Abstract / Description: Urbanization is a largely irreversible anthropogenic change that degrades environmental quality, including aquatic ecosystems. Stormwater ponds are a popular best management practice (BMP) to mitigate the effects of urban land use on downstream water bodies and contribute significantly to the total area of aquatic ecosystems in some urban watersheds. My research investigated the distribution of stormwater ponds and examined how different urban land uses influenced biophysicochemical...
Show moreUrbanization is a largely irreversible anthropogenic change that degrades environmental quality, including aquatic ecosystems. Stormwater ponds are a popular best management practice (BMP) to mitigate the effects of urban land use on downstream water bodies and contribute significantly to the total area of aquatic ecosystems in some urban watersheds. My research investigated the distribution of stormwater ponds and examined how different urban land uses influenced biophysicochemical conditions and management of those ponds in a rapidly developing suburban watershed in the Econlockhatchee River basin in Florida, USA. I evaluated limnological and ecological parameters in randomly-selected ponds distributed among three urban land-use classes: high-density residential, institutional, and roadways. Ecological measures included characterizing percentage cover and composition of littoral zone plant community and the extent of any algal mats. Limnological measures included physical parameters (pH, conductivity, dissolved oxygen, and clarity), and nutrient concentrations (nitrate, ammonium, total nitrogen, dissolved reactive phosphorus, total phosphorus, and chlorophyll a). I used a subjective management intensity index to compare pond management among land-use classes. Stormwater ponds represented 40.2% of the total area of non-forested freshwater systems in the watershed, and were dominated by residential land uses (43.7%), followed by roadways (14.7%), industrial (2.7%) and institutional (2.3%). Principal Component Analysis (PCA) revealed that ponds with higher total nitrogen (TN) and chlorophyll a (chla) concentrations had lower water clarity, and that both. TN and TP were positively correlated with chla. PCA scores for school ponds, which had the highest water clarity, differed significantly from those of expressway and residential ponds, along the first PCA axis. Repeated-measures analysis of variance showed that TN concentrations differed significantly between expressway and school ponds, with expressway ponds having TN concentrations 51.7% higher than schools. Both TP and TN varied differently through time in the different lands uses. Management intensity for removal of aquatic vegetation and algae was lower in school ponds than in expressway and residential ponds, and school ponds contained the highest abundance and diversity of vegetation. Different urban land uses had varying impacts on water quality, and more intense chemical use to control vegetation and algae was related to greater nutrient and chla concentrations and lower water clarity.
Show less
Date Issued: 2016
Identifier: CFE0006845, ucf:51781
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006845

Title: Ichetucknee Springs: Measuring the Effects of Visitors on Water Quality Parameters through Continuous Monitoring.
Creator: Faraji, Sarah, Singh, Arvind, Wang, Dingbao, Mayo, Talea, University of Central Florida
Abstract / Description: Ichetucknee Springs System is in north central Florida, under the jurisdiction of the Suwannee River Water Management District (SRWMD). The Ichetucknee River is one of the most pristine spring-fed rivers in Florida and became a state park in 1970. Over 400,000 people visited the Ichetucknee Springs State Park in 2016. From that total, over 130,000 people came during the tubing season alone (Memorial Day to Labor Day). During the tubing season, only 750 visitors per day are allowed to launch...
Show moreIchetucknee Springs System is in north central Florida, under the jurisdiction of the Suwannee River Water Management District (SRWMD). The Ichetucknee River is one of the most pristine spring-fed rivers in Florida and became a state park in 1970. Over 400,000 people visited the Ichetucknee Springs State Park in 2016. From that total, over 130,000 people came during the tubing season alone (Memorial Day to Labor Day). During the tubing season, only 750 visitors per day are allowed to launch from the North Launch, near the Ichetucknee Head Spring. The park enforces visitor usage of the river during these time frames to protect the integrity of the aquatic vegetation and aquatic organisms in the northern portion of the River. The objective of this study is to evaluate the response of water quality from the Head Spring to the seasonal changes in visitor numbers to the Park. Water quality parameters were continuously monitored and recorded by a SRWMD station using a YSI EXO2 and SUNA nitrate sensor: temperature, turbidity, pH, specific conductivity, dissolved oxygen content, and nitrates (NO2+NO3). Water quality data from April 2015 to September 2017 was reviewed and processed into max daily values that were compared to daily visitor counts. Results from the statistical analysis indicate there is a significant difference in turbidity from the Head Spring during the tubing season and outside the tubing season (Kruskal-Wallis, p(<)0.001), which results from higher visitor counts during the weekends of the tubing season. However, due to inconsistency of water quality readings and equipment damage, some data were lost or outside the range of monitoring capabilities; which may have resulted in decreased correlation between water quality and daily visitor counts. Continued evaluation of water quality by continuous monitoring is warranted as it can assist the SRWMD and Ichetucknee Springs State Park Staff better monitor and evaluate the health of the Ichetucknee Springs System.
Show less
Date Issued: 2017
Identifier: CFE0006873, ucf:51748
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006873

Title: Effects of climate change and anthropogenic activities on the Everglades landscape.
Creator: Sandhu, Daljit, Singh, Arvind, Wang, Dingbao, Medeiros, Stephen, University of Central Florida
Abstract / Description: The Everglades has been experiencing major changes, both climatic and anthropogenic, such that the landscape is experiencing additional stresses and forcings leading it away from its natural equilibrium. The land within and surrounding the Everglades has undergone severe modifications that may have detrimental effects on wildlife and natural features, such as rivers and landscape connectivity. Here in this study, the main focus is on understanding and quantifying hydrologic and geomorphic...
Show moreThe Everglades has been experiencing major changes, both climatic and anthropogenic, such that the landscape is experiencing additional stresses and forcings leading it away from its natural equilibrium. The land within and surrounding the Everglades has undergone severe modifications that may have detrimental effects on wildlife and natural features, such as rivers and landscape connectivity. Here in this study, the main focus is on understanding and quantifying hydrologic and geomorphic signatures of climatic and anthropogenic changes on the Everglades landscape. For this, in particular, available data on natural hydrological processes was used, such as rainfall, groundwater elevation, streamflow as well as surface elevations and satellite images for three different regions. These regions are categorized as forested, urban (nearby Everglades regions) and transition (in between forested and urban regions). The results show distinct differences in the statistics of observed hydrologic variables for the three different regions. For example, the probability distribution functions (PDFs) of groundwater elevation for the case of urban region show a shift in mean as well as lower asymmetry as compared to forested regions. In addition, a significant difference in the slopes between smaller and larger scales of the power spectral densities (PSDs) is observed when transitioning from forested to urban. For the case of the streamflow PDFs and PSDs, the opposite trends are observed. Basin properties extracted from digital elevation models (DEMs) of the Everglades reveal that drainage densities increase when moving from the urban to the forested sub-regions, highlighting the topographic and land use/land cover changes that the Everglades has been subjected to in recent years. Finally, computing the interarrival times of extreme ((>)95th percentile) events that suggest power-law behavior, the changes in power-law exponents of the hydrologic processes further highlights how these processes differ spatially and how the landscape has to respond to these changes. Quantifying these observed changes will help develop a better understanding of the Everglades and other wetlands ecosystems for management to future changes and restoration.
Show less
Date Issued: 2016
Identifier: CFE0006495, ucf:51395
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006495

LiDAR (5)	+ -
climate change (5)	+ -
remote sensing (4)	+ -
groundwater (3)	+ -
sea level rise (3)	+ -

sinkhole (3)	+ -
Apalachicola (2)	+ -
Evaporation (2)	+ -
Gulf of Mexico (2)	+ -
SWAT (2)	+ -
Silver Springs (2)	+ -
Sinkhole (2)	+ -
Turbidity (2)	+ -
Water balance (2)	+ -
climate aridity index (2)	+ -
groundwater depletion (2)	+ -
management (2)	+ -
nitrate (2)	+ -
perennial stream (2)	+ -
water balance (2)	+ -
ADCIRC (1)	+ -
ARIMA model (1)	+ -
Africa drought (1)	+ -
Anion Exchange (1)	+ -
Annual Water Balance (1)	+ -
Apalachicola National Estuarine Research Reserve (1)	+ -
AquaCrop (1)	+ -
Asymmetry (1)	+ -
BAM (1)	+ -
Base flow recession (1)	+ -

University of Central Florida (54)	+ -
Wang, Dingbao (54)	+ -
Chopra, Manoj (15)	+ -
Medeiros, Stephen (11)	+ -
Hagen, Scott (10)	+ -

Singh, Arvind (10)	+ -
Nam, Boo Hyun (9)	+ -
Duranceau, Steven (7)	+ -
Randall, Andrew (7)	+ -
Kibler, Kelly (6)	+ -
Weishampel, John (6)	+ -
Chang, Ni-bin (5)	+ -
Madani Larijani, Kaveh (5)	+ -
Sumner, David (5)	+ -
Wanielista, Martin (4)	+ -
Bohlen, Patrick (3)	+ -
Mayo, Talea (3)	+ -
Sadmani, A H M Anwar (3)	+ -
Gogo-Abite, Ikiensinma (2)	+ -
Nnadi, Fidelia (2)	+ -
O'Reilly, Andrew (2)	+ -
Quintana-Ascencio, Pedro (2)	+ -
Reinhart, Debra (2)	+ -
Rowney, Alexander (2)	+ -
Sandhu, Daljit (2)	+ -
Xanthopoulos, Petros (2)	+ -
Yestrebsky, Cherie (2)	+ -
Zheng, Qipeng (2)	+ -
Abdel-Aty, Mohamed (1)	+ -
Al-Labban, Salama (1)	+ -

Search In

Pages

Pages

Sort Results By:

Narrow results by:

Topical Subject

Collection

Type of Resource

Language

Creator

Format

Owner