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(1 - 17 of 17)
- Title
- The effects of urbanization on cypress (Taxodium distichum) in central Florida.
- Creator
-
McCauley, Lisa, Jenkins, David, Quintana-Ascencio, Pedro, Hoffman, Eric, Ewel, Kathy, University of Central Florida
- Abstract / Description
-
Urbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of...
Show moreUrbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of urbanization on cypress domes. Specifically, I tested how urbanization and its effects on fragmentation, hydrology, and fire regime) affected (a) the numbers and spatial pattern of cypress domes in central Florida and (b) the recruitment of cypress within cypress domes. Analysis of historical loss found over 3,000 cypress domes identified in images from1984, of which 26% were lost or degraded (i.e., no longer cypress-dominated) by 2004. Due to changed land use, many remaining cypress domes, formerly surrounded by natural lands, have become surrounded by urban lands causing spatial clustering and homogenization. Surprisingly, I found that both natural and urban cypress domes showed lower recruitment than agricultural cypress domes, where the natural fire regime has not been altered. The probability of cypress recruitment in cypress domes urbanized for more than 20 years is very low. Previous to that, cypress tends to recruit on the edge of cypress domes where there is less competition and hydrological conditions are more favorable. I estimate that only ~50% of the current cypress domes are recruiting and the existence of those wetlands are tied to the lifespan of the current adults. By 2104, I estimate that ~89% of the cypress domes currently recruiting will fail to recruit. I believe that reducing urban sprawl and restoring the natural fire regime to natural cypress domes will mitigate the current fate of cypress domes. Without this, cypress in isolated wetlands in central Florida, and providing Orlando urbanization is typical, throughout urbanized areas of the range, could be at risk. Cypress in urban areas will be then relegated to riparian zones and with unknown consequences for the species that utilize the former cypress dome habitat.
Show less - Date Issued
- 2011
- Identifier
- CFE0004136, ucf:49065
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004136
- Title
- Remote Sensing of Coastal Wetlands: Long term vegetation stress assessment and data enhancement technique.
- Creator
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Tahsin, Subrina, Medeiros, Stephen, Singh, Arvind, Mayo, Talea, University of Central Florida
- Abstract / Description
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Apalachicola Bay in the Florida panhandle is home to a rich variety of salt water and freshwater wetlands but unfortunately is also subject to a wide range of hydrologic extreme events. Extreme hydrologic events such as hurricanes and droughts continuously threaten the area. The impact of hurricane and drought on both fresh and salt water wetlands was investigated over the time period from 2000 to 2015 in Apalachicola Bay using spatio-temporal changes in the Landsat based NDVI. Results...
Show moreApalachicola Bay in the Florida panhandle is home to a rich variety of salt water and freshwater wetlands but unfortunately is also subject to a wide range of hydrologic extreme events. Extreme hydrologic events such as hurricanes and droughts continuously threaten the area. The impact of hurricane and drought on both fresh and salt water wetlands was investigated over the time period from 2000 to 2015 in Apalachicola Bay using spatio-temporal changes in the Landsat based NDVI. Results indicate that salt water wetlands were more resilient than fresh water wetlands. Results also suggest that in response to hurricanes, the coastal wetlands took almost a year to recover while recovery following a drought period was observed after only a month. This analysis was successful and provided excellent insights into coastal wetland health. Such long term study is heavily dependent on optical sensor that is subject to data loss due to cloud coverage. Therefore, a novel method is proposed and demonstrated to recover the information contaminated by cloud. Cloud contamination is a hindrance to long-term environmental assessment using information derived from satellite imagery that retrieve data from visible and infrared spectral ranges. Normalized Difference Vegetation Index (NDVI) is a widely used index to monitor vegetation and land use change. NDVI can be retrieved from publicly available data repositories of optical sensors such as Landsat, Moderate Resolution Imaging Spectro-radiometer (MODIS) and several commercial satellites. Landsat has an ongoing high resolution NDVI record starting from 1984. Unfortunately, the time series NDVI data suffers from the cloud contamination issue. Though simple to complex computational methods for data interpolation have been applied to recover cloudy data, all the techniques are subject to many limitations. In this paper, a novel Optical Cloud Pixel Recovery (OCPR) method is proposed to repair cloudy pixels from the time-space-spectrum continuum with the aid of a machine learning tool, namely random forest (RF) trained and tested utilizing multi-parameter hydrologic data. The RF based OCPR model was compared with a simple linear regression (LR) based OCPR model to understand the potential of the model. A case study in Apalachicola Bay is presented to evaluate the performance of OCPR to repair cloudy NDVI reflectance for two specific dates. The RF based OCPR method achieves a root mean squared error of 0.0475 sr?1 between predicted and observed NDVI reflectance values. The LR based OCPR method achieves a root mean squared error of 0.1257 sr?1. Findings suggested that the RF based OCPR method is effective to repair cloudy values and provide continuous and quantitatively reliable imagery for further analysis in environmental applications.
Show less - Date Issued
- 2016
- Identifier
- CFE0006546, ucf:51331
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006546
- Title
- Mucking About: Hydrologic Regime and Soil Carbon Storage in Restored Subtropical Wetlands.
- Creator
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Huber, Alicia, Bohlen, Patrick, Hinkle, Ross, Chambers, Lisa, University of Central Florida
- Abstract / Description
-
Wetlands are extremely important ecosystems that have declined drastically worldwide, continue to be lost, and are threatened globally. They perform a number of important ecosystem services such as flood control, provide habitat for many species, and have aesthetic and recreational value. Wetlands are also important to the global carbon (C) cycle. Wetland soils are especially effective C sinks because they have high primary productivity and low decomposition rates due to flooded, anoxic...
Show moreWetlands are extremely important ecosystems that have declined drastically worldwide, continue to be lost, and are threatened globally. They perform a number of important ecosystem services such as flood control, provide habitat for many species, and have aesthetic and recreational value. Wetlands are also important to the global carbon (C) cycle. Wetland soils are especially effective C sinks because they have high primary productivity and low decomposition rates due to flooded, anoxic conditions. Increased recognition of wetlands' value has led to more ecological and hydrological restoration of degraded wetlands to mitigate the effects of wetland destruction. Hydrological restoration, which attempts to recreate natural hydroperiod and water levels in wetlands, is expected to increase soil C storage. Many studies have estimated the C stock in different wetland ecosystems across biomes, but few have examined hydrological drivers of soil C variation across wetland types. This study investigated the relationship between hydrologic variables (hydroperiod and average water depth) and soil C storage in three types of hydrologically restored wetlands (marsh, bay swamp, and cypress swamp) at the Disney Wilderness Preserve (DWP) in central Florida, USA. I collected 150 50-cm soil cores along existing monitoring transects in sampled wetlands where water elevation data had been collected since 1995 to examine the relationship between hydrologic variable and soil C storage. I analyzed a combination of generalized linear mixed models (glmm), evaluated using AICc. Mean water depth was a better predictor than hydroperiod of soil C concentration and stock. Mean water depth had a significant positive relationship with soil C concentration in bay swamps and marshes and soil C stock in marshes. However, this effect was small and often outweighed by other factors such as differences in vegetative community, soil depth, or local site conditions. Water depth had no significant relationship with soil C concentration in cypress swamps or upland communities or on soil C stock in bay swamps, cypress swamps, or uplands. Wetland community type had a strong influence on soil C variation, with bay swamp soils having the highest mean soil C concentration followed by cypress swamp, marsh, and upland soils, respectively. Soil C concentration generally decreased with soil depth. Bay swamps also had the highest soil C stock, followed by cypress swamp, marsh, and upland soils, respectively. Together, the sampled wetland communities cover approximately 22% of the sampled communities at DWP, yet store an estimated 47% of the total soil C to a 90 cm depth. The results of this study affirm the importance of inundation for soil C storage in wetlands, but also highlight that there are a number of other complex variables affecting soil C in different types of wetlands such as differences in litter quality and decomposition rates.
Show less - Date Issued
- 2017
- Identifier
- CFE0007122, ucf:51930
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007122
- Title
- Biogeochemical effects of sea level rise-induced transitions within coastal wetlands.
- Creator
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Steinmuller, Havalend, Chambers, Lisa, Hinkle, Ross, Bohlen, Patrick, Beazley, Melanie, University of Central Florida
- Abstract / Description
-
As sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation...
Show moreAs sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation shifts, and submergence were investigated. Changes in nutrient dynamics associated with saltwater intrusion were evaluated by artificially adding saline water to different freshwater wetland soil types, indicating that potential exports of critical nutrients (forms of nitrogen, phosphorus, and C) out of freshwater wetland soils is mediated by soil type. A controlled laboratory experiment was conducted to determine the potential degradability of C stored within submerging coastal wetland soils under both aerobic and anaerobic conditions. Under aerobic conditions, 66% more carbon dioxide was produced than under anaerobic conditions and 4x greater carbon dioxide was produced at 90-100cm depths than at the surface. At the same site, the degradability of carbon stores was examined through organic matter fractionation, stable isotopic examination, and determining the abundance of key microbial genes. Both total soil C and stores of bioavailable nutrients increased with depth, while organic matter quality decreased. Finally, the biogeochemical impacts of two separate vegetation transitions occurring co-incidentally with sea level rise were investigated: mangrove encroachment into salt marsh, and more salt- and inundation-tolerant herbaceous encroachment into herbaceous marsh. Conclusions from these studies demonstrate that vegetation transitions alter both soil nutrient storage and fast-cycling nutrient pools, indicating that biogeochemical transitions occur in advance of changes in vegetative species dominance. Results from these chapters holistically address how biogeochemical functioning, specifically nutrient cycling, regulation of water quality, and C sequestration, within coastal wetlands responds to stressors associated with SLR.
Show less - Date Issued
- 2019
- Identifier
- CFE0007536, ucf:52584
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007536
- Title
- Wetland diversity in a disturbance-maintained landscape: Effects of fire and a fire surrogate on aquatic amphibian survival and species depauperateness.
- Creator
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Klaus, Joyce, Noss, Reed, Quintana-Ascencio, Pedro, Jenkins, David, Dr. L. Katherine Kirkman, University of Central Florida
- Abstract / Description
-
Disturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open...
Show moreDisturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open-structured, fire-maintained vegetation but shrubs and trees encroach into fire-dependent ecosystems where fire has been excluded. Prescribed burning and mechanical removal are commonly used as restoration tools to control encroachment. To better assess and compare the restoration potential of these tools, a more thorough understanding of how they change vegetation structure and habitat suitability for animals is necessary.The southeastern U.S. is a diversity hot-spot for amphibians, many of which require ephemeral wetlands embedded in longleaf pine uplands for the aquatic phase of their life cycle. Amphibian diversity has been declining in recent decades and habitat loss/degradation has been cited as one of the leading causes. Although often overlooked in studies of fire ecology, the ephemeral wetlands required by many amphibians are also fire-dependent habitats that have been negatively impacted by lack of fire. To understand how disturbance interacts with wetland vegetation and aquatic-phase amphibians, three disturbance treatments meant to mimic the effects of natural disturbance on vegetation structure were applied randomly to 28 dry ephemeral wetlands in the Lower Coastal Plain of South Carolina, U.S. The treatments consisted of early growing-season prescribed fire, mechanical vegetation removal (a proposed fire surrogate), and a combination of mechanical removal plus fire; some sites were left untreated for reference. Vegetation structure was quantified and amphibian assemblages were monitored before and after treatments. In addition, one species of amphibian was used in a tadpole survival experiment to examine differences in performance among treatments. Other factors that could be affected by treatments and in turn influence amphibians were measured, including water chemistry, wetland depth, quantity and quality of epilithon, and leaf litter composition.Amphibian survival was lowest, and species depauperateness highest in untreated wetlands. Depauperateness of species whose range was restricted to the range of longleaf pine was lowest in sites that had mechanical treatment plus fire. The mechanical plus fire treatment created the most open vegetation structure with lowest leaf litter accumulation, especially of hardwood litter, conditions correlated with high amphibian survival and diversity. When data from this study was combined with data from a previous study of similar nearby wetlands, a pattern emerged in which one suite of species was absent from recently burned sites, while an entirely different suite of species was absent from long-unburned sites. This evidence suggests that disturbance is related to a shift in amphibian assemblage possibly due to changes in vegetation structure and perhaps wetland ecology in general, from an algal-based system maintained by frequent fire to a detrital-based system that develops in the absence of fire.
Show less - Date Issued
- 2013
- Identifier
- CFE0005015, ucf:49994
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005015
- Title
- SPATIOTEMPORAL VARIATION OF AVIAN POPULATIONS WITHIN GEOGRAPHICALLY ISOLATED FRESHWATER MARSHES.
- Creator
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Rodenbeck, Brian, Weishampel, John, University of Central Florida
- Abstract / Description
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Metacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species...
Show moreMetacommunity connectivity, i.e., multi-species dispersal events, is vital to metapopulation persistence in patchy landscapes. Assessments of metacommunity connectivity are not trivial. However, a relationship between trophic rank and the species-area relationship has been found in previous studies, allowing for the use of the predator species-area relationship to act as a surrogate measure of actual metacommunity connectivity of prey species in some systems. For this study, avian species were selected as they are generalist top predators within the study system. Predator species richness within geographically isolated freshwater marshes is influenced by a number of factors. I explore the relative roles of patch area, seasonality, hydroperiod, isolation, and vegetation structure on habitat use in the isolated freshwater marshes embedded within the dry prairie ecosystem of Central Florida. Predator species richness was surveyed in 50 sites for three seasons: fall 2005, winter 2005/06, and spring 2006 and the observed avian assemblage measures were subdivided into foraging guilds for analysis. Wading guild (e.g., egrets, herons, bitterns) species richness was correlated with hydroperiod and vegetation structural variables while perching guild (e.g., blackbirds, sparrows, meadowlarks) species richness was correlated with isolation, hydroperiod, and area annually. Overall predator and all guild species richness measures were also correlated with patch area for all seasons. These results suggest that while a complex mixture of patch area, hydroperiod and isolation influence habitat utilization that varies by season and at the community, guild and individual species level, the underlying predictors that define habitat use in wetlands annually includes hydroperiod, and is not exclusively patch area. Additionally, seasonal differences in predator species richness were found to be significant in some cases indicating that future avian population studies may benefit by sampling outside of the normally studied spring breeding season. Results of this study support the use of predator species richness as a suitable assay of metacommunity connectivity of prey species. Applications and implications of this approach toward future conservation efforts are discussed.
Show less - Date Issued
- 2007
- Identifier
- CFE0001766, ucf:47253
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001766
- Title
- USING GIS TO DETERMINE THE INFLUENCE OF WETLANDS ON CAYUGA IROQUOIS SETTLEMENT LOCATION STRATEGIES.
- Creator
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Birnbaum, David, Walker, John, University of Central Florida
- Abstract / Description
-
The archaeological record of the Iroquois supports that settlements were regularly relocated during the protohistoric period (1500-1650 A.D.). With the use of Geographic Information Systems (GIS) computer software, archaeologists may analyze variables potentially resulting in or influencing the movement of settlements. Through the use of spatial analysis, I argue that Cayuga Iroquois settlement locations were influenced by the environmental characteristics of their surrounding landscape....
Show moreThe archaeological record of the Iroquois supports that settlements were regularly relocated during the protohistoric period (1500-1650 A.D.). With the use of Geographic Information Systems (GIS) computer software, archaeologists may analyze variables potentially resulting in or influencing the movement of settlements. Through the use of spatial analysis, I argue that Cayuga Iroquois settlement locations were influenced by the environmental characteristics of their surrounding landscape. Specifically, wetlands are believed to have influenced settlement location choices in central New York state. This study examines the spatial relationships between wetland habitats and protohistoric period Cayuga Iroquois settlements where swidden maize agriculture comprised most of the diet. Considering previous research that has linked the movement of settlements to Iroquois agricultural practices, I hypothesize that wetlands played a significant role in the Iroquois subsistence system by providing supplementary plant and animal resources to a diet primarily characterized by maize consumption, and thereby influenced the strategy behind settlement relocation. Nine Cayuga Iroquois settlements dating to the protohistoric period were selected for analysis using GIS. Two control groups, each consisting of nine random points, were generated for comparison. Distance buffers show the amount of wetlands that are situated within 1-, 2.5-, and 5-kilometers from Cayuga settlements and random points. The total number of wetlands within proximity of these distances to the settlements and random points are recorded and analyzed. The results indicate a statistical significance regarding the prominence of wetlands within the landscape which pertains to the Cayuga Iroquois settlement strategy.
Show less - Date Issued
- 2011
- Identifier
- CFH0004118, ucf:44873
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004118
- Title
- REMOTE SENSING WITH COMPUTATIONAL INTELLIGENCE MODELLING FOR MONITORING THE ECOSYSTEM STATE AND HYDRAULIC PATTERN IN A CONSTRUCTED WETLAND.
- Creator
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Mohiuddin, Golam, Chang, Ni-bin, Lee, Woo Hyoung, Wanielista, Martin, University of Central Florida
- Abstract / Description
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Monitoring the heterogeneous aquatic environment such as the Stormwater Treatment Areas (STAs) located at the northeast of the Everglades is extremely important in understanding the land processes of the constructed wetland in its capacity to remove nutrient. Direct monitoring and measurements of ecosystem evolution and changing velocities at every single part of the STA are not always feasible. Integrated remote sensing, monitoring, and modeling technique can be a state-of-the-art tool to...
Show moreMonitoring the heterogeneous aquatic environment such as the Stormwater Treatment Areas (STAs) located at the northeast of the Everglades is extremely important in understanding the land processes of the constructed wetland in its capacity to remove nutrient. Direct monitoring and measurements of ecosystem evolution and changing velocities at every single part of the STA are not always feasible. Integrated remote sensing, monitoring, and modeling technique can be a state-of-the-art tool to estimate the spatial and temporal distributions of flow velocity regimes and ecological functioning in such dynamic aquatic environments. In this presentation, comparison between four computational intelligence models including Extreme Learning Machine (ELM), Genetic Programming (GP) and Artificial Neural Network (ANN) models were organized to holistically assess the flow velocity and direction as well as ecosystem states within a vegetative wetland area. First the local sensor network was established using Acoustic Doppler Velocimeter (ADV). Utilizing the local sensor data along with the help of external driving forces parameters, trained models of ELM, GP and ANN were developed, calibrated, validated, and compared to select the best computational capacity of velocity prediction over time. Besides, seasonal images collected by French satellite Pleiades have been analyzed to address the seasonality effect of plant species evolution and biomass changes in the constructed wetland. The key finding of this research is to characterize the interactions between geophysical and geochemical processes in this wetland system based on ground-based monitoring sensors and satellite images to discover insight of hydraulic residence time, plant species variation, and water quality and improve the overall understanding of possible nutrient removal in this constructed wetland.
Show less - Date Issued
- 2014
- Identifier
- CFE0005533, ucf:52864
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005533
- Title
- Biomass density based adjustment of LiDAR-derived digital elevation models: a machine learning approach.
- Creator
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Abdelwahab, Khalid, Medeiros, Stephen, Mayo, Talea, Wahl, Thomas, University of Central Florida
- Abstract / Description
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Salt marshes are valued for providing protective and non-protective ecosystem services. Accurate digital elevation models (DEMs) in salt marshes are crucial for modeling storm surges and determining the initial DEM elevations for modelling marsh evolution. Due to high biomass density, lidar DEMs in coastal wetlands are seldom reliable. In an aim to reduce lidar-derived DEM error, several multilinear regression and random forest models were developed and tested to estimate biomass density in...
Show moreSalt marshes are valued for providing protective and non-protective ecosystem services. Accurate digital elevation models (DEMs) in salt marshes are crucial for modeling storm surges and determining the initial DEM elevations for modelling marsh evolution. Due to high biomass density, lidar DEMs in coastal wetlands are seldom reliable. In an aim to reduce lidar-derived DEM error, several multilinear regression and random forest models were developed and tested to estimate biomass density in the salt marshes near Saint Marks Lighthouse in Crawfordville, Florida. Between summer of 2017 and spring of 2018, two field trips were conducted to acquire true elevation and biomass density measures. Lidar point cloud data were combined with vegetation monitoring imagery acquired from Sentinel-2 and Landsat Thematic Mapper (LTM) satellites, and 64 field biomass density samples were used as target variables for developing the models. Biomass density classes were assigned to each biomass sample using a quartile approach. Moreover, 346 in-situ elevation measures were used to calculate the lidar DEM errors. The best model was then used to estimate biomass densities at all 346 locations. Finally, an adjusted DEM was produced by deducting the quartile-based adjustment values from the original lidar DEM. A random forest regression model achieved the highest pseudo R2 value of 0.94 for predicting biomass density in g/m2. The adjusted DEM based on the estimated biomass densities reduced the root mean squared error of the original DEM from 0.38 m to 0.18 m while decreasing the raw mean error from 0.33 m to 0.14 m, improving both measures by 54% and 58%, respectively.
Show less - Date Issued
- 2019
- Identifier
- CFE0007594, ucf:52535
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007594
- Title
- NUTRIENT REMOVAL FROM URBAN STORMWATER USING FLOATING TREATMENT WETLAND SYSTEM.
- Creator
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Islam, Md. Kamrul, Chang, Ni-bin, University of Central Florida
- Abstract / Description
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Despite the technology advancement, degradation of water quality due to stormwater continues to be a significant threat to the water and ecosystems due to the exponential growth of industries and agricultural enterprises that discharge stormwater. These anthropogenic activities are the sources of high nitrogen and phosphorus quantities in stormwater, which is responsible for eutrophication phenomena and deterioration of public health. Floating Treatment Wetlands (FTWs) are a potential...
Show moreDespite the technology advancement, degradation of water quality due to stormwater continues to be a significant threat to the water and ecosystems due to the exponential growth of industries and agricultural enterprises that discharge stormwater. These anthropogenic activities are the sources of high nitrogen and phosphorus quantities in stormwater, which is responsible for eutrophication phenomena and deterioration of public health. Floating Treatment Wetlands (FTWs) are a potential solution to this problem. Both microcosm and mesocosm level studies were conducted for the effective removal of nutrients in stormwater wet detention ponds with different sorption media under varying nutrient concentrations and weather conditions. Water depth, percent area coverage of the FTWs and littoral zone emergent plants were varied in order to determine nutrient removal efficiency before implementing in an actual pond. Focus has also been placed on the observations of macrophyte-epiphyte-phytoplankton interactions in order to understand temporal characteristics of ecological phenomena. Water quality parameters included Total Nitrogen, Total Phosphorus, Orthophosphate, Nitrate-Nitrogen, and Ammonia-Nitrogen in addition to in-situ parameters such as pH, Dissolved Oxygen, Temperature and Chlorophyll-a. Results clearly indicate that an FTW filled with sorption media of 80% expanded clay and 20% tire crumb can significantly promote the biomass growth. Different levels of nutrient concentrations did affect the plants' growth and cold temperature in late winter was detrimental to growth. To make the system more viable irrespective of the seasonal weather conditions, the adoption of mixed vegetation is highly recommended in the FTWs implementation. It is also recommended that, the positioning of the floating wetlands should not be in the vicinity of the outlet of the pond as assimilated nutrient under the mat might increase the nutrient concentration in the discharged water. Finally, One-way ANOVA test is performed to check whether or not these grouped microcosms and mesocosms with differing experimental setup can be deemed statistically significant.
Show less - Date Issued
- 2011
- Identifier
- CFE0004013, ucf:49171
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004013
- Title
- NUTRIENT AND PATHOGEN REMOVAL IN A SUBSURFACE UPFLOW WETLAND SYSTEM USING GREEN SORPTION MEDIA.
- Creator
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Xuan, Zhemin, Chang, Ni-Bin, University of Central Florida
- Abstract / Description
-
Due to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely...
Show moreDue to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely affect public health. A subsurface upflow wetland, which is an effective small-scale wastewater treatment system with low energy and maintenance requirements and operational costs, fits the current nutrient and pathogen removal situation having received wide attention throughout the world. Within this research study, a subsurface upflow wetland system (SUW), including four parallel SUW (three planted versus one unplanted), were constructed as a key component of the septic tank system receiving 454 liters per day (120 GPD) influent using the green sorption media along with selected plant species. It was proved effective in removing both nutrients and pathogens. During a one month test run, the planted wetlands achieved a removal efficiency of 84.2%, 97.3 %, 98.93 % and 99.92%, compared to the control wetland, 10.5%, 85.7 %, 99.74 % and 100.0 %, in total nitrogen (TN), total phosphorus (TP), fecal coli and E.Coli, respectively. Denitrification was proved to be the dominant pathway for removing N as evidenced by the mass balance and real-time PCR analyses. A simplified compartmental dynamics simulation model of constructed subsurface upflow wetlands was also developed to provide a dependable reference and tool for design of constructed subsurface upflow wetland.
Show less - Date Issued
- 2009
- Identifier
- CFE0002967, ucf:47964
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002967
- Title
- THE EFFECTS OF URBANIZATION ON THE STRUCTURE, QUALITY, AND DIVERSITY OF CYPRESS PLANT COMMUNITIES IN CENTRAL FLORIDA.
- Creator
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Knickerbocker, Courtney, Quigley, Martin, University of Central Florida
- Abstract / Description
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The integrity of wetland ecosystems is largely determined by hydrological functionality, degree of connectivity to like ecosystems, and permeability to external influence. Land use changes in upland areas adjacent to wetland ecosystems may influence hydrology and connectivity while introducing novel biotic and abiotic materials. There is an increasing trend toward the use of remote assessment techniques to determine the degree of impact of external influences on adjacent wetlands. Remote...
Show moreThe integrity of wetland ecosystems is largely determined by hydrological functionality, degree of connectivity to like ecosystems, and permeability to external influence. Land use changes in upland areas adjacent to wetland ecosystems may influence hydrology and connectivity while introducing novel biotic and abiotic materials. There is an increasing trend toward the use of remote assessment techniques to determine the degree of impact of external influences on adjacent wetlands. Remote assessment and predictive capabilities are provided by indices such as the Landscape Development Intensity Index (LDI) (Brown and Vivas 2005) which may be beneficial in determining site condition, and which have the added benefit of providing a quantitative gradient of human impact. This study assessed the predictive ability of the LDI in cypress ecosystems, by testing its correlations with plant community metrics including an index of floral quality calculated using coefficients of conservatism (CC)(Cohen et al. 2004), plant species diversity, and fluctuation in community composition assessed by changes in the wetland status and native status of component plant species. LDI was also compared against an independent measure of disturbance which was used to construct an a priori disturbance gradient. Overall, diversity measures showed little correlation with any of the disturbance indices, while CC scores were significantly correlated. Models were constructed in an attempt to explain each of the variables of plant community response to development in the surrounding landscape. The length of time since the development of the land adjacent to the cypress domes was a predictor of plant community response only when included in models with other variables. LDI was the strongest predictor in all models except where increases in land use associated with hydrological changes helped predict or better predicted proportions of exotic and upland species.
Show less - Date Issued
- 2009
- Identifier
- CFE0002576, ucf:48280
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002576
- Title
- On the Back of the Crocodile: Extent, Energetics, and Productivity in Wetland Agricultural Systems, Northern Belize.
- Creator
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Montgomery, Shane, Chase, Arlen, Chase, Diane, Walker, John, University of Central Florida
- Abstract / Description
-
Ancient populations across the globe successfully employed wetland agricultural techniques in a variety of environmentally and climatically diverse landscapes throughout prehistory. Within the Maya Lowlands, these agricultural features figure prominently in the region comprised of northern Belize and southern Quintana Roo, an area supporting low-outflow rivers, large lagoons, and numerous bajo (swamp) features. Along the banks of the Hondo and New Rivers, the Maya effectively utilized wetland...
Show moreAncient populations across the globe successfully employed wetland agricultural techniques in a variety of environmentally and climatically diverse landscapes throughout prehistory. Within the Maya Lowlands, these agricultural features figure prominently in the region comprised of northern Belize and southern Quintana Roo, an area supporting low-outflow rivers, large lagoons, and numerous bajo (swamp) features. Along the banks of the Hondo and New Rivers, the Maya effectively utilized wetland agricultural practices from the Middle Preclassic to the Terminal Classic Periods (1000 B.C.(-)A.D. 950). A number of past archaeological projects have thoroughly examined the construction and impact of these swampland modifications. After four decades of study, a more precise picture has formed in relation to the roles that these ditched field systems played in the regional development of the area. However, a detailed record of the full spatial extent, combined construction costs, and potential agricultural productivity has not been attempted on a larger scale. This thesis highlights these avenues of interest through data obtained from high- and medium-resolution satellite imagery and manipulated through geographic information systems (GIS) technology. The research explores environmental factors and topographic elements dictating the distribution of such entities, the energetic involvement required to construct and maintain the systems, and the efficiency of wetland techniques as compared to traditional milpa agriculture. Spatial analyses reveal a total of 254 distinct wetland field systems within the 6560 square kilometer area of interest, clustered along navigable waterways, seasonal lagoons, and upland landscapes separating the Hondo and New Rivers. Energetic estimates illustrate substantial investment in wetland field construction, spanning several generations based on a locally available workforce. However, productivity calculations associated with the ditched field systems commonly exceed those attributed to milpa techniques, suggesting agricultural surplus far beyond the immediate need. These combined data indicate the potential export of maize and other agricultural commodities to regional centers in northern Belize and further abroad during the Late Preclassic and Late to Terminal Classic Periods through riverine trade networks. Additionally, these data help illustrate participation trends and patterns of connectivity relating to tiered sites within the area of interest. This research contributes to the overall understanding of wetland agriculture within Mesoamerica as well as provides insight into the political management of intensive agricultural production during Maya prehistory.
Show less - Date Issued
- 2016
- Identifier
- CFE0006360, ucf:51514
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006360
- Title
- Low Impact Development Analysis and Comparative Assessment of Wet Detention Ponds with Floating Treatment Wetlands.
- Creator
-
Hartshorn, Nicholas, Chang, Ni-bin, Kibler, Kelly, Wanielista, Martin, University of Central Florida
- Abstract / Description
-
The aim of this thesis is to examine, develop, and assess innovative best management practices (BMPs) in stormwater management for pollutant reduction, flood control, and environmental sustainability. Previous research has clearly shown that urban stormwater runoff quickly transports pathogens, metals, sediment, and chemical pollutants to receiving waterbodies, resulting in the degradation of receiving waters and disruption of ecological networks. In response to this growing concern,...
Show moreThe aim of this thesis is to examine, develop, and assess innovative best management practices (BMPs) in stormwater management for pollutant reduction, flood control, and environmental sustainability. Previous research has clearly shown that urban stormwater runoff quickly transports pathogens, metals, sediment, and chemical pollutants to receiving waterbodies, resulting in the degradation of receiving waters and disruption of ecological networks. In response to this growing concern, regulatory agencies, such as the Environmental Protection Agency (EPA) and the Florida Department of Environmental Protection (FDEP), have set forth regulations aimed at protecting and restoring waterbodies. These regulations include numeric nutrient criteria (NNC) and total maximum daily loads (TMDLs), which enable effective monitoring of a waterbody with regard to nitrogen and phosphorus pollution and help to restore waters not attaining their designated uses. Currently, many stormwater management systems do not provide sufficient nutrient reduction to meet growing regulations; thus, there is a clear need to develop additional BMPs to enhance nutrient reduction.Firstly, this thesis provides an overview of BMPs used in urban regions across the globe to create networks of low impact development (LID), with a focus on policy analysis. Chapter 2 examines the regulatory policies in areas of the United States, Europe, Asia, and Australia from a federal, state, to local perspective in order to pinpoint what policies are supporting the shift from gray cities to green cities. Gray cities are cities comprised mainly of impervious surfaces, with little regard to the ecological health and hydrologic characteristics of the area. Green cities utilize LID to mimic pre-development hydrologic and ecological characteristics, resulting in a city that is both environmentally sustainable and offers many ecosystem services. The results of the global policy analysis identified the policies and other factors, such as funding and public involvement, necessary to facilitate the shift from gray cities to green cities and support the widespread implementation of LID.Secondly, this thesis provides a comparative analysis of three stormwater wet detention ponds, which all contained floating treatment wetlands (FTWs). FTWs are a new BMP, used to enhance nutrient reduction rates in stormwater wet detention ponds. FTWs are a manmade ecosystem, utilizing plants that grow on interlocking floating foam mats, that mimics natural wetlands. Both episodic (storm event) and routine (non-storm event) sampling campaigns were carried out at the three stormwater wet detention ponds located in Gainesville, Ruskin, and Orlando, Florida. The comparative analysis of the three stormwater wet detention ponds was based on two perspectives. The fist analysis, found in Chapter 2, focuses solely on the nutrient reduction potential of FTWs and how the installation of FTWs can be used to improve nutrient reduction rates in stormwater wet detention ponds. The second analysis, found in Chapter 3, focuses on the interaction between nutrients, microcystin, and chlorophyll-a in the stormwater wet detention ponds before and after installation of the FTWs. These two studies provide a holistic understanding of the environmental and ecological aspects of utilizing FTWs as a BMP in stormwater management. FTWs were found to have a significant impact on nutrient reduction rates in the three stormwater wet detention ponds, with total nitrogen (TN) reduction rates reaching 33% at the Ruskin pond during storm events and total phosphorus (TP) reduction rates reaching 71% at the Gainesville pond during storm events. Moreover, microcystin concentrations were found to have a negative correlation with nutrient concentrations, specifically total phosphorus, for both storm and non-storm events across all three ponds.
Show less - Date Issued
- 2016
- Identifier
- CFE0006113, ucf:51206
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006113
- Title
- Evaluating Floating Treatment Wetlands to Improve Nitrogen Removal in a Wet Detention Pond.
- Creator
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Marimon, Zachary, Chang, Ni-bin, Fauth, John, Bohlen, Patrick, University of Central Florida
- Abstract / Description
-
Wet detention ponds are used for stormwater treatment across the United States and reduce most pollutants by at least 60%, but only remove 30% of total nitrogen. Floating Treatment Wetlands (FTWs) are an emerging technology that uses aquatic plants suspended in the pelagic zone to remove nitrogen through vegetative assimilation and microbial denitrification. A before-after field experiment evaluated nitrogen removal in a an existing pond in Orlando, FL, retrofitted with BioHaven(&)#174; FTWs...
Show moreWet detention ponds are used for stormwater treatment across the United States and reduce most pollutants by at least 60%, but only remove 30% of total nitrogen. Floating Treatment Wetlands (FTWs) are an emerging technology that uses aquatic plants suspended in the pelagic zone to remove nitrogen through vegetative assimilation and microbial denitrification. A before-after field experiment evaluated nitrogen removal in a an existing pond in Orlando, FL, retrofitted with BioHaven(&)#174; FTWs planted with the aquatic macrophytes Juncus effusus (Soft Rush) and Pontederia cordata (Pickerelweed). Surface water samples were used to compare the nitrogen-removal performance of the pond under both storm and non-storm conditions during a pre-analysis phase (control) to post-analysis after FTW deployment. The evaluation revealed similar TN removals in non-storm conditions during pre-analysis and post-analysis periods (-1% and -3%, respectively). During storm conditions, there was a negative TN removal of -26% in the pre-analysis compared to the positive 29% removal post-analysis. In addition, nitrogen concentrations for organic-nitrogen, ammonia/ammonium, and nitrites/nitrates were used as input for calibrating and validating a system dynamics model to predict multiple, interacting nitrogen species' transformation and translocation across the abiotic and biotic components of water, sediment, plants, and atmosphere. The validated model created in STELLA v.9.4.1 was used to simulate alternative designs to achieve maximum nitrogen removal based on the treatment efficiency in the evaluation. Simulations predicted 60% FTW coverage at the experimental planting density (22 per square meter) could achieve maximum nitrogen removal. Alternatively, similar nitrogen removal could be achieved at only 15% FTW coverage by increasing plant density. The model can be used as a low-cost tool for designing FTW technology applications and monitoring nitrogen transport.
Show less - Date Issued
- 2016
- Identifier
- CFE0006140, ucf:51168
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006140
- Title
- Green Technologies and Sensor Networks for BMP Evaluation in Stormwater Retention Ponds and Wetlands.
- Creator
-
Crawford, Anthony, Chang, Ni-bin, Wanielista, Martin, Lee, Woo Hyoung, University of Central Florida
- Abstract / Description
-
The aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of...
Show moreThe aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of Environmental Protection (FDEP) has set forth reduction goals as established in Total Maximum Daily Load (TMDL) reports to reduce nutrient loading and restore, or maintain, Florida water bodies to reasonable conditions. Often times current stormwater management practices are not sufficient to attain these goals and further improvements in system design are required. In order to reach these goals, affordable technologies designed for both nutrient reduction and monitoring of system performance to deepen and improve our understanding of stormwater processes are required. Firstly this thesis examines the performance of three types of continuous-cycle Media Bed Reactors (MBRs) using Bio-activated Adsorptive Media (BAM) for nutrient reduction in three retention ponds located throughout the Central Florida region. Chapter 2 examines the use of a Sloped and Horizontal MBRs arranged in a baffling configuration, whereas Chapter 3 examines the field performance of a Floating MBR arranged in an upflow configuration. Each MBR was analyzed for performance in reducing total phosphorus, soluble reactive phosphorus, total nitrogen, organic nitrogen, ammonia, nitrates + nitrites, turbidity and chlorophyll a species as measured from the influent to effluent ends of the MBR. The results of the experiments indicate that MBRs may be combined with retention ponds to provide (")green technology(") alternatives for inter-event treatment of nutrient species in urban stormwater runoff by use of recyclable sorption media and solar powered submersible pumps. Secondly the thesis focusses on three new devices for BMP monitoring which may be integrated into wireless networks, including a Groundwater Variable Probe (GVP) for velocity, hydraulic conductivity and dispersion measurements in a retention pond bank (Chapter 4), an affordable Wireless Automated Sampling Network (WASN) for sampling and analysis of nutrient flux gradients in retention ponds (Chapter 5), and finally an Arc-Type Automated Pulse Tracer Velocimeter (APTV) for low velocity and direction surface water measurements in retention ponds and constructed wetlands (Chapter 6). The GVP was integrated with other environmental sensing probes to create a remote sensing station, capable of real-time data analysis of sub-surface conditions including soil moisture, water table stage. Such abilities, when synced with user control capabilities, may help to increase methods of monitoring for applications including erosion control, bank stability predictions, monitoring of groundwater pollutant plume migration, and establishing hydraulic residence times through subsurface BMPs such as permeable reactive barriers. Advancement of this technology may be used by establishing additional sub-stations, thereby creating sensing networks covering broader areas on the kilometer scale. Two methods for velocity calculation were developed for the GVP for low flow (Pe (<) 0.2) and high flow (Pe (>) 0.6) conditions. The GVP was found to operate from a 26-505 cmd-1 range in the laboratory to within (&)#177;26% of expected velocities for high-flow conditions and effectively measure directional flow angles to within (&)#177;14? of expected. Hydraulic conductivity measurements made by the GVP were confirmed to within (&)#177;12% as compared to laboratory measurements. The GVP was found capable of measuring the dispersion coefficient in the laboratory, however turbulent interferences caused during injection was found to occur. Further advancement of the technology may be merited to improve dispersion coefficient measurements. Automated water sampling can provide valuable information of the spatial and temporal distribution of pollutant loading in surface water environments. This ability is expanded with the development of the WASN, providing an affordable, ease-of-use method compared to conventional automated water samplers currently on the market. The WASN was found to effectively operate by text activation via GSM cellular networks to an activation module. Propagation of the signal was distributed to collection units via XBee modules operating on point-to-point star communication using an IEEE 802.15.4 protocol. Signal communications effectively transmitted in the field during a storm event to within a range of 200 feet and collected 50 (&)#177;4 ml samples at synced timed increments. A tracer study confirmed that no mixing of samples occurs when a factor of safety of 2 is applied to flush times. This technology provides similar abilities to current market devices at down to 10% of the cost, thereby allowing much more sampling locations for a similar budget. The Arc-Type APTV is useful in establishing both low range horizontal velocity fields and expanding low range velocity measurements below detection ranges of mechanical velocity meters. Installation of a field station showed system functionality, which may be integrated with other environmental sensing probes for surface water testing. This may assist in nutrient distribution analysis and understanding the complex behavior of hydraulic retention times within wetland systems. The device was found to work effectively in both lab and field environments from a 0.02 (-) 5.0 cms-1 range and measure velocity within approximately (&)#177;10% of an acoustic Doppler velocimeter and within an average of (&)#177;10? of directional measurements. A drop in accuracy was measured for velocity ranges (>)4.5 cms-1. The field station operated on 3G CDMA cellular network two-way communication by installation of a Raven cellular modem. Use of LoggerNet software allowed control and data acquisition from anywhere with an internet connection. This thesis also introduces brief discussions on expanding these (")point(") measurement technologies into sensing networks. Installation of sub-stations with communication protocols to one central master node station may broaden the sensing system into much larger kilometer-scale ranges, thus allowing large spatial analysis of environmental conditions. Such an integration into controllable sensing networks may help bridge the gap and add calibration and verification abilities between fine-resolution (")point(") measurements and large scale technologies such as Electrical Resistivity Tomography and satellite remote sensing. Furthermore, application of sensing networks may assist in calibration and verification of surface and groundwater models such as ModFlow, SVFlux and FEHM.
Show less - Date Issued
- 2014
- Identifier
- CFE0005776, ucf:50066
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005776
- Title
- Understanding Hydroclimatic Controls on Stream Network Dynamics using LiDAR Data.
- Creator
-
Kim, Seoyoung, Wang, Dingbao, Medeiros, Stephen, Nam, Boo Hyun, Singh, Arvind, Sumner, David, University of Central Florida
- Abstract / Description
-
This dissertation investigates the hydroclimatic controls on drainage network dynamics and characterizes the variation of drainage density in various climate regions. The methods were developed to extract the valley and wet channel networks based on Light Detection and Ranging (LiDAR) data including the elevation and intensity of laser returns. The study watersheds were selected based on the availability of streamflow observations and LiDAR data. Climate aridity index was used as a...
Show moreThis dissertation investigates the hydroclimatic controls on drainage network dynamics and characterizes the variation of drainage density in various climate regions. The methods were developed to extract the valley and wet channel networks based on Light Detection and Ranging (LiDAR) data including the elevation and intensity of laser returns. The study watersheds were selected based on the availability of streamflow observations and LiDAR data. Climate aridity index was used as a quantitative indicator for climate. The climate controls on drainage density were re-visited using watersheds with minimal anthropogenic interferences and compared with the U-shape relationship reported in the previous studies. A curvature-based method was developed to extract a valley network from 1-m LiDAR-based Digital Elevation Models. The relationship between drainage density and climate aridity index showed a monotonic increasing trend and the discrepancy was explained by human interventions and underestimated drainage density due to the coarse spatial resolution (30-meter) of the topographic maps used in previous research. Observations of wet channel networks are limited, especially in headwater catchments in comparison with the importance of stream network expansion and contraction. A systematic method was developed to extract wet channel networks based on the signal intensities of LiDAR ground returns, which are lower on water surfaces than on dry surfaces. The frequency distributions of intensities associated with wet surface and dry surface returns were constructed. With the aid of LiDAR-based ground elevations, signal intensity thresholds were identified for extracting wet channels. The developed method was applied to Lake Tahoe area during recession periods in five watersheds. A power-law relationship between streamflow and wet channel length was obtained and the scaling exponent was consistent with the reported findings from field work in other regions.Perennial streams flow for the most of the time during normal years and are usually defined based on a flow duration threshold. The streamflow characteristics of perennial streams in this research were assessed using the relationship between streamflow exceedance probability and wet channel ratio based on wet channel networks extracted from LiDAR data. Non-dimensional analysis based on the relationship between streamflow exceedance probability and wet channel ratio showed that results were consistent with previous research about perennial stream definition, and provided the possibility to use wet channel ratio to define perennial streams. Wetlands are important natural resources and need to be monitored regularly in order to understand their inundation dynamics, function and health. Wetland mapping is a key part of monitoring programs. A framework for detecting wetland was developed based on LiDAR elevation and intensity information. After masking out densely vegetated areas, wet areas were identified based on signal intensity of ground returns for barrier islands in East-Central Florida. The intensity threshold of wet surface was identified by decomposing composite probability distribution functions using a Gamma mixture model and the Expectation-Maximization algorithm. This method showed good potential for wetland mapping.The methodology developed in this dissertation demonstrated that incorporating LiDAR data into the drainage networks, stream network dynamics and wetlands results in enhanced understanding of hydroclimatic controls on stream network dynamics. LiDAR data provide a rich information source including elevation and intensity, and are of great benefit to hydrologic research community.
Show less - Date Issued
- 2016
- Identifier
- CFE0006532, ucf:51372
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006532
