Spelling suggestions: "subject:"coastal managemement"" "subject:"coastal managementment""
41 |
Matriz de Interações Costeiras : valoração das interações no litoral de Jaguaruna – SC.Watanabe, Túlio Pires January 2015 (has links)
A zona costeira no Brasil tem mostrado progressiva concentração e diversificação das atividades humanas e já demonstra comprometimento dos recursos naturais e ecossistemas. Localizado no Sudeste do estado de Santa Catarina, o município de Jaguaruna possui área de 328,347 km² e 37 km de orla. A orla do município, assim como nos níveis regional, nacional ou global é o resultado da interação do continente com o mar. Da grande variedade de usos que nela se aplicam, torna mais complexa sua análise e planejamento. Nos seus subsistemas (meio físico natural, socioeconômico, e político jurídico administrativo) possuem suas complexidades e seus conflitos. Seja na degradação ambiental, nos conflitos de usos ou na ilegalidade de alguns empreendimentos, a gestão e planejamento destas problemáticas é uma meta a ser alcançada. Para subsidiar este objetivo, esta dissertação aprimora o método de valoração de conflitos da orla, a Matriz de Interações Costeiras, observando e analisando as interações entre usos e estruturas na orla do município. Juntamente com a aplicação da Matriz de Interações Costeiras, este trabalho desenvolve uma caracterização do meio físico natural e socioeconômico proporcionando uma visão de espaço geográfico que auxilia na compreensão e comparação dos resultados obtidos na Matriz. Nesta caracterização foi concluído que o espaço geográfico de Jaguaruna possui suas sensibilidades ambientais e praias de grande valor cênico, que sua economia, baseada no setor de serviços, ainda pode ser mais diversificada buscando atividades turísticas como matriz. Ainda, na aplicação da Matriz de Interações Costeiras, observou-se uma insatisfação da população quanto à gestão do território urbano, revelando nos conflitos de uso a ausência de planejamento. / The coastal zone in Brazil has shown a progressive concentration and diversification of human activities and has demonstrated commitment of natural resources and ecosystems. Located in the southeastern state of Santa Catarina, the city has an area of Jaguaruna 328.347 km² and 37 km of coastline. The edge of the city, as well as in regional, national or global levels is the result of the continent's interaction with the sea. The wide variety of uses to which it applies, becomes more complex analysis and planning. In its subsystems (the natural physical, socio-economic, administrative and legal political) have their complexities and conflicts. Be environmental degradation, conflicts of uses or illegality of some projects, the management and planning of these issues is a goal to be achieved. To support this goal, this work enhances the valuation method of the waterfront conflicts, Matrix Coastal Interactions, observing and analyzing the interactions between uses and structures in the city's waterfront. Along with the application of the Coastal Interactions Matrix, this paper develops a characterization of the natural and socioeconomic physical environment providing a view of geographic space that helps to understand and compare the results obtained in the Matrix. This characterization was concluded that the geographic space Jaguaruna has its environmental sensitivities and great scenic value of beaches, its economy based on the services sector, may still be seeking more diverse tourist activities as matrix. Still, the implementation of Coastal Interactions Matrix, there was a dissatisfaction of the population as the management of urban territory, revealing the use conflicts the lack of planning.
|
42 |
A Comparative Study on Coastal Zone Changes and Anthropogenic Impacts between Tampa Bay, USA, and Xiangshan Harbor, China, during the Last 30 YearsGuo, Qiandong 28 June 2018 (has links)
Currently, the U.S. and China are the two largest national economic entities in the world. However, it is noticeable that the two countries have considerably different strategies for economic development, environmental protection and land supply in coastal zones. In order to understand the coastline dynamics, land use land cover (LULC) changes and land management policies in the U.S. and China, a case study of the Tampa Bay (TB) watershed, Florida, U.S., and Xiangshan Harbor (XH), Zhejiang Province, China was conducted. The two areas possess similar humid subtropical climate and dense population, but experienced different anthropogenic impacts. TB sat at a developed stage with sound environmental laws, regulations and projects to preserve natural landscapes. XH was at a developing stage and focused more on an economic development in the last 30 years. Comparing the LULC change patterns and the major driving forces for the changes between the two study areas, governments and public could know what factors cause the land use conversion and how to preserve the natural landscapes. A new water index called the weighted normalized water index (WNDWI) was proposed to extract coastlines in TB and XH since current water indices could not classify turbid water bodies and shadow areas well. Two threshold methods (i.e., Otsu threshold method and multiple thresholds method) were implemented to find an optimal threshold to segment the water from the land. The experiments demonstrate that the WNDWI algorithm can achieve high accuracies to classify water from land with an optimal threshold in the two study sites. Coastlines in 1985, 1995, 2005 and 2015 in TB and XH were extracted and the changes were detected and highlighted. The results indicate that coastlines in TB were mostly stable, while those in XH had been undergoing intensive human interferences, indicating that XH was at a developing stage. Major anthropogenic impacts on XH coastlines are land reclamation and aquaculture, resulting in an impacted area of approximately 20.3 km2. The land cover maps of TB and XH in 1985 (1986), 1995, 2005 and 2015 were produced by classifying Landsat images using the random forest algorithm. The reflectance distributions of the land cover types indicate that it is difficult to classify agricultural land, rangeland, upland forest and wetland if using the optical bands only from a single Landsat image. Multi-seasonal image composites and the land surface temperature (LST) band were involved in image classification to achieve higher accuracies. The overall accuracies (OAs) of the land cover map of TB in 2015 and that of XH in 2005 were increased by 5.14% and 4.33% after adding the LST band. The OAs of the four years’ land cover maps of TB range from 81.14% to 83.43%, whereas those of XH vary from 84.67% to 87.67%. According to the experimental results, the total urban area increased by 11.8% in TB, while that in XH increased 138.9% during the last 30 years. Wetland in TB reduced by 8.3% while that in XH reduced 49.0%. The results of logistic regression analysis indicated that the density of wetland is a major driver for urban growth in TB with a strong negative impact while the relationship is opposite in XH. It is worth noting that XH has been undergoing a rapid urbanization and industrialization process with a vast amount of natural landscapes converted to urban areas, whereas TB has already passed the developing stage and issued environmental laws and programs to preserve natural landscapes from human exploitation. In terms of preserving natural landscapes and protecting the vulnerable coastal environment for our next generation, the coastal planning decision makers in XH should not only consider economic values and short-term benefits but also integrate values of ecological, social, and cultural and long-term benefits when making coastal management decisions.
|
43 |
Mangroves, Mudbanks and Seawalls: Political Ecology of Adaptation to Sea Level Rise in SurinameNijbroek, Ravic 01 January 2012 (has links)
This study seeks to understand how global discourses of sea level rise (SLR) and mangrove ecology influence national climate change adaptation policy to reduce coastal vulnerability in Suriname. A majority of the Surinamese population lives along the low elevation coastal zone and is highly exposed to projected SLR. Failure by the international community to reach agreement on climate change mitigation means that vulnerable coastal communities must adapt. The Suriname coast is predominantly shaped by mudbanks and mangroves which together provide protection against coastal erosion and trap sediments resulting in coastal accretion. Knowledge claims of mangrove ecology and utility in SLR adaptation are contested between scientists, policy makers and community activist groups. Scientific understandings of coastal processes, specifically the relationship between mangroves and mudbanks and resulting erosion, remain inconclusive. Local knowledge has offered alternative explanations for this relationship, but it also has limitations, particularly for large-scale ecological processes. This study argues that global discourses of SLR and mangrove ecology need to be countered for sustainable adaptation to ALR. Equitable adaptation should include local knowledge and understanding of coastal processes while also drawing on scientific methods of data analysis at large scales.
|
44 |
Cooperative binational coastal zone management : recommendations for Texas and TamaulipasBarraza Lizárraga, Eleonor 21 November 2013 (has links)
The Gulf of Mexico is a shared resource at risk. It is facing many problems such
as exponential population growth, degrading water quality, consequences of oil and gas
activities, unsustainable exploitation of resources, and lack of public education and
political interest. In response, Mexico and the United States have devised their own set of
programs and strategies to best manage their coastal zones. There have been a few
official coastal management efforts between the U.S. Gulf states and Mexico. However,
the existence of these collaborative programs does not supplant the need for a binational,
integrated coastal management effort. Texas and Tamaulipas have participated in these
cooperation programs, but direct coastal collaboration between the two states has been
limited. Although there is an obvious disparity between the two regarding CZM practices,
both states face similar challenges that require a cooperative effort and combined resources. This report explores different alternatives for binational cooperation between
Texas and Tamaulipas at the regional level, in the context of the existing CZM
frameworks and strategies of each state. / text
|
45 |
Isotopic ecosystem studies in the KwaZulu-Natal Bight.De Lecea, Ander Martinez. 11 November 2013 (has links)
The study area, the KwaZulu-Natal Bight, is an oceanographically important area, which, regardless of having two of the most important fisheries off the east coast of South Africa, has received little research attention regarding its biological functioning. Until now chiefly oceanographic processes have been considered the drivers of this generally oligotrophic system. This study seeks to understand which of three important processes, a topographically induced oceanic upwelling cell near Richards Bay, a cyclonic eddy near Durban, or fluvial fluxes centred around the Thukela River, forces ecological functioning through their nutrient or organic matter input. The overall aim of the thesis is to understand the pelagic and benthic ecosystems of the Bight in terms of these drivers through the use of stable isotope (δ¹³C and δ¹⁵N) analyses of a range of biotic and abiotic samples. These were collected on board of a number of research cruises – forming predominantly part of the larger African Coelacanth Ecosystem Programme suite of studies – in the wet and dry seasons of 2010.
Isotopic analyses found distinctions between fluvial and oceanic particulate organic matter and indicate that upwelling was not occurring in either sampling season. Organic matter originating from the Thukela River did not play a significant role in the wet season, although it dominated the planktonic pelagic food web in the dry season. The organic matter of the most productive region in the Bight, the Middle Shelf, was of riverine origin in the dry season, but of indeterminate origin in the wet season when it may have been an artefact of an old upwelling event which had previously occurred to the north of the Bight. There is, however, some evidence suggesting that this organic matter may rather have been of riverine origin, with its δ¹³C signals subsequently having been modified by the diatom bloom occurring there.
In the demersal ecosystem, sediment isotopic data show organic matter to be well-mixed throughout the Bight in both seasons, with riverine organic matter dominating most of the Bight except its northern and southern edges, where oceanic organic matter increases in importance. Sediment organic matter (most likely via the macrobenthic biota) was deemed an important food source for demersal animals and omnivory an
important feeding strategy. Seasonal studies from 2008 to 2010 in the Thukela Bank area indicate that the demersal animals' stable isotope signatures responded to the seasonal isotopic changes in riverine organic matter, indicating the cross-seasonal importance of this food source to the demersal ecosystem.
Parallel methodological studies examined how routine isotopic sample handling procedures could have affected the results of the ecological studies. These studies suggest that i) effects of preservation/fixation methods and the use of dyes are species-dependant; ii) acidification has no effect on zooplankton isotopic signatures, and that iii) drying methods alone and interactively with multiple thawing and refreezing of samples affect the stable isotope values offish muscle tissues. Recommendations are made for further improvements in methodology and considerations to be taken when processing samples.
Overall, it is concluded that riverine input to the Bight has a more important biological role than previously thought, and that organic matter from this source is an important driver of ecosystems within the Bight throughout the year for the demersal and pelagic ecosystems. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2012.
|
46 |
The use of the toxicity identification and evaluation (TIE) protocol in the Port of Durban, South Africa.Parsons, Gary Angus. January 2011 (has links)
The Port of Durban, with its close proximity to industrial, urban and agricultural activities, receives a number of chemical pollutants that settle out and accumulate in sediments. Chemical analysis of these sediments has indicated elevated levels of chemicals that, according to sediment quality guidelines, might cause adverse biological effects. However, elevated concentrations alone do not necessarily imply that chemicals are present in bioavailable concentrations high enough to be harmful to organisms that come into contact with them. Thus, chemical tests alone cannot provide an accurate indication of the potential adverse biological effects of these chemicals.
In this regard, toxicity tests of sediment porewaters have been developed using sea urchin gametes to assist in determining the bioavailability of chemicals present in porewaters. Further, procedures such as Toxicity Identification and Evaluation (TIE), which involves the manipulation and/or treatment of toxic porewater, have also been developed to assist in the isolation and identification of chemicals causing porewater toxicity.
In this research, on a number of sampling occasions between July 2007 and July 2009, three replicate sediment samples were extracted from a site in the Port of Durban known to contain sediment with potentially toxic porewater. Results of initial toxicity tests, using the sea urchin fertilisation test indicated the presence of toxic porewater although, in some instances, porewater toxicity was highly variable between replicate samples. However, results from TIE procedures performed to reduce potentially toxic concentrations of metals, ammonia and organic compounds did not resolve the primary cause of porewater toxicity.
Further research indicated that chemicals including hydrogen sulphide, which can occur naturally in organically enriched sediments, may have been confounding factors that masked the potential toxicity of other chemicals present in the sediment samples. Consequently, a sampling strategy and modified TIE procedure have been recommended. The sampling strategy has been designed to assist with detecting and understanding any sample variability that may occur. The modified TIE procedure, which suggests initial procedures to determine and reduce/remove the possible confounding effects of potential naturally occurring compounds such as hydrogen sulphide from the porewater, could be used in future to understand and evaluate the quality of contaminated sediments from similar environments. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.
|
47 |
Recovery dynamics of zooplankton following a mouth-breaching event in the temporarily-open Mdloti Estuary.Deale, Maria. January 2010 (has links)
A high proportion of South Africa’s temporarily open/closed estuaries (TOCEs) occur along
the coast of KwaZulu-Natal. Mouth breaching events have major impacts on the biological
processes of an estuary, resulting in depletion of zooplankton via flushing and sediment
scouring. Mouth closure, usually within weeks of a breaching event, initiates a new phase of
stable physical conditions, leading to biological recovery. Therefore, the aim of this
investigation was: (1) to monitor the recovery of zooplankton abundance and biomass
following a breaching event in the Mdloti Estuary; (2) to compare the spatial and temporal
patterns in zooplankton distribution in the lower (mouth), middle and upper reaches (head) of
the Mdloti Estuary in terms of abundance and biomass just before, during and after a mouth
breaching event; and (3) to determine the key environmental variables influencing
zooplankton abundance and biomass during such a breaching event. The zooplankton
community of the Mdloti Estuary was studied over a 3-month period (27 January to 26 April
2004). The estuary was artificially breached on 12 February 2004, due to a fish kill, and
closed again naturally on 18 March 2004. Samples were collected twice a week in the lower,
middle and upper reaches using a WP-2 net and an epibenthic sled. Upon breaching, 98% of
zooplankton biomass was lost through sediment scouring and flushing. During the open
phase, zooplankton biomass showed a temporary recovery, but due to continual sediment
scouring and flushing, this was not sustained. One-way ANOVA revealed a significant
difference in total zooplankton abundance and biomass between phases (d.f.2, 59 = 55.0; p <
0.001; d.f.2, 59 = 15.51; p < 0.001). ANCOVA revealed significant differences between
zooplankton abundance and biomass (d.f.0.05;2,56=2.97, p = 0.05) at the different estuarine
reaches (d.f.0.05;2,56=5.51, p < 0.01) . In both cases, the lower reaches recovered quicker than
the middle and upper reaches. Thirty-five taxa were identified during the study, with only 10
contributing more than 1% of the total abundance or biomass. For the overall study, P. hessei
was the dominant species, accounting for 42% of the total abundance and 58% of the total
biomass. Keratella sp. 1 accounted for 17% and 11% of the total abundance and total
biomass, respectively, while harpacticoid copepodites and Acartia natalensis contributed 11%
and 10% to the total zooplankton abundance and 3% and 7% to the total zooplankton
biomass, respectively. Pre-breaching levels of zooplankton were reached only 9 days after
the closure of the mouth, during the recovery phase (mean 1.1 x 105 ± 6.5 x 104 SD ind.m3
and 2.4 x 102 ± 1.6 x 102 SD mg.m3). Zooplankton abundance and biomass reached a peak in
the lower reaches after 19 days, in the upper reaches after 28 days and in the middle reaches
after 35 days. The zooplankton biomass decreased slightly, but stabilised for the duration of
the study. During the study the state of the mouth was primarily responsible for regulating the
zooplankton abundance and biomass. However, the zooplankton in the different reaches did
not recover in synchrony after mouth re-closure because abiotic factors and food availability
were different in the three estuarine reaches. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2010.
|
48 |
Spatial and temporary variations in macrozoobenthic communities in KwaZulu-Natal temporarily open/closed estuaries.Stow, Catherine Anne. January 2011 (has links)
Estuaries are complex ecosystems, typified by remarkable fluctuations in environmental conditions. In addition to this natural variability, stochastic events and anthropogenic influences effect change at different spatial and temporal scales. Macrozoobenthic invertebrates are preferable biological indicators because of their sensitivity to variations in habitat quality. This thesis describes inherent changes in the macrozoobenthos of temporarily open/closed estuaries (TOCEs) in KwaZulu-Natal, ‘change’ as measured in spatial and temporal community differences using various community metrics, namely species composition, abundance and diversity. Standard and widely published quantitative sampling techniques were employed, with simultaneous measurements of ambient physico-chemical conditions, including sediment characteristics. The thesis is in three parts. Regional distributions and long-term decadal-type changes in macrozoobenthic community structure were determined for 31 TOCEs using historical data (1998/9) compared with more recently collected data (2009/10). Results showed that, although of the same estuary type, the macrozoobenthic communities of these estuaries differed significantly. Furthermore, community composition did not reflect a north to south progression of predominantly tropical species to predominantly warm-temperate species. In the last decade, the macrozoobenthos of these systems had indeed changed (in composition, abundance and/or diversity), the scale of change within each estuary being estuary-dependent. The recolonisation of two urban and non-urban estuaries by macrozoobenthos following a stochastic flood disturbance was investigated, describing the short-term community changes during the recovery process. Differential recolonisation patterns were attributed to inherent differences in community composition and not to the influence of urbanisation. Recolonisation was marked by distinct changes in community structure, with the recovery trajectory being interrupted by localised disturbances (e.g. change of mouth state). Species indicative of the observed spatial and temporal community changes were examined for similarities in habitat association and trophic characteristics. The species that were representative of these KwaZulu-Natal TOCEs were identified and included common and highly abundant generalists of varying trophic groups. In conclusion, the present findings illustrated the effectiveness of using macrozoobenthic communities to depict ‘change’ over multiple temporal and spatial scales. This also supports their usefulness as a study group in environmental monitoring and detecting the loss of ecological functioning and biodiversity in estuaries in the long- and short-term. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.
|
49 |
A study of the net flux of nitrates from three estuaries of the eThekwini Municipality of Durban, KwaZulu-Natal.Fernandes, Sarah. January 2011 (has links)
Estuaries, the interface of interaction of fluvial discharge and marine action serve as temporary repositories of materials (solid and dissolved) before finally exporting them to sea. This interchange of material is dependent on a range of factors such as tidal range, prism, and symmetry; fluvial flows and estuarine morphodynamics. The efficacy of transfer of materials to the marine environment is important for estuarine health particularly in estuaries located in highly developed areas such as the major coastal metropolitan areas of many countries. This study assesses the efficacy of the export of nitrates from three estuaries of the eThekwini Municipality of the city of Durban, South Africa which maintain an open mouth status, ensuring tidal exchange throughout the year.
The focus of this study was to determine and analyze the net flux of nitrates between the Isipingo, Mgeni, and Tongati estuaries of the eThekwini Municipality, and their adjacent nearshore environments. It questioned whether the Isipingo, Mgeni, and Tongati estuaries were efficient at exporting nitrates to their adjacent marine environments. The abovementioned estuaries are classified as temporarily open/closed estuaries, and were chosen for this study, as they maintain an open mouth status for most of the year. An open mouth condition was critical in order to conduct this study, as tidal exchange, and the resulting nitrate fluxes, could occur. The net flux of nitrates was measured for these estuaries on a seasonal basis for both spring and neap tides. Measurements were taken over the tidal cycle, ensuring that the peak high and low tides were sampled. To determine the values of net flux, the cross-sectional area of the estuary mouths were measured; average flow velocities of water were measured; and average concentrations of nitrates were obtained.
Results indicate that although there is a net export of nitrates to the nearshore environment, there were instances, particularly on the spring tide, when a net import of nitrates into the estuary occurred. The origin of the latter is likely derived from nearshore upwelling; unusually high biotic decomposition at sea and/or the longshore drift transport of decomposing sewage outfall.
This creates an added dimension for consideration in estuarine management plans. Taking all three estuaries studied into consideration, a net export of nitrates for all seasons for the eThekwini Municipality was measured with a clear seasonal influence detected where high rainfall seasons led to greater export as a consequence of greater fluvial flows, erosion and leaching of agricultural lands and longer ebb duration. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.
|
50 |
Phytoplankton studies in the KwaZulu-Natal Bight.Omarjee, Aadila. January 2012 (has links)
The KwaZulu-Natal Bight is an important area along the South African east coast, stretching 160 km
north from Scottsburgh to St Lucia (Lutjeharms et al., 2000). The Bight is of interest to the region as
the area contains some distinct physical features, which are presumed to drive the ecological
functioning of the shelf ecosystem through their role in nutrient sources. These include the Tugela
River, the second largest river in South Africa in terms of outflow, and the Agulhas Current that forms
an outer border at the edge of the continental shelf.
Phytoplankton interacts with the majority of essential ecological networks and therefore greatly
influences marine ecosystems. To this end, it is necessary to understand their ecophysiological rate
processes – particularly those that are influenced by the dominant nutrient inputs to the Bight. The
overall aim of this project is therefore to provide an insight into the sources of nutrients driving
phytoplankton productivity in the Bight.
Synoptic surveys were conducted to provide an indication of the distribution of Total Suspended
Solids (TSS), Particulate Organic Matter (POM) and phytoplankton in the Bight, while focussed
experiments used stable isotopes to examine the rate processes involving C and N acquisition, as well
as sources of N available in the surface water.
Concentration of particulate organic phosphorus and nitrogen were found to be higher in the wet
season when compared to the dry season. During the wet season a large variation in chlorophyll-a
fluorescence was observed across the Bight, while natural abundance isotope data indicated a seasonal
change in the nutrient source available. For the wet season nutrient concentration varied with site and
depth, however uptake rates (μg N.1ˉ¹.hˉ¹) measured using ¹⁵N tracer additions were not significantly
different with site and depth. Alternatively, the dry season showed a significant difference between
site in surface waters. In the wet season the mid shelf area had the highest uptake rate and
phytoplankton biomass while the Richards Bay north site dominated, with regard to the previously
mentioned factors, in the dry season. At the time of the experiments, neither the Durban eddy nor the
upwelling cell were present, and hypotheses regarding the importance of these physical features in
driving phytoplankton nutrient acquisition could not be assessed. However, a notable difference in
uptake rate between the wet and dry seasons was observed, and this difference is likely due to the
fluvial sources of nutrients from the Tugela and many other rivers entering the KZN coast, which are
absent during the dry season.
The results indicate that terrestrial nutrient sources play a major role in influencing nutrient
concentrations on the Bight, and hence influence the nearshore ecosystem of the region. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
|
Page generated in 0.0997 seconds