145,756 research outputs found

    Develping a Methodology for the Mapping and Characterization of the Nigerian Coastline Using Remote Sensing

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    Coastline delineation is important in maritime boundary determination, as well as for analyzing coastline change rates due to coastal erosion, sea level change, storms, and other causes. Coastline change rate estimates depend on the uncertainty of the current and historical coastlines used in the analysis, which, in turn, depend on the surveying technologies and techniques that were originally used. Current techniques for coastline mapping include photogrammetric delineation using tide-coordinated aerial imagery. However, in many developing countries, the charted coastlines may have been inadequately and inconsistently mapped largely due to inadequate resources. This paper describes the use of an automated technique for coastline mapping and classification that is based on satellite imagery. A spectral analysis using different image bands can be used to define the land/water boundary and characterize the coastal area around the coastline. A first-order uncertainty analysis was also performed. The satellite-derived coastlines were compared to charted coastlines to evaluate the adequacy and consistency of the charted coastlines. The satellite-derived coastlines were also compared to coastlines derived from historical maps to assess changes and change rates. The results of the coastline uncertainty analysis were then used to compute propagated uncertainties in coastline change rate estimates and to gain greater insight into actual changes. The procedure was developed in a GIS environment using study sites along the Nigerian coastline. However, this procedure can be applied to other poorly charted/mapped coastal areas as well

    Coastline Kriging: A Bayesian Approach

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    Statistical interpolation of chemical concentrations at new locations is an important step in assessing a worker's exposure level. When measurements are available from coastlines, as is the case in coastal clean-up operations in oil spills, one may need a mechanism to carry out spatial interpolation at new locations along the coast. In this paper we present a simple model for analyzing spatial data that is observed over a coastline. We demonstrate four different models using two different representations of the coast using curves. The four models were demonstrated on simulated data and one of them was also demonstrated on a dataset from the GuLF STUDY. Our contribution here is to offer practicing hygienists and exposure assessors with a simple and easy method to implement Bayesian hierarchical models for analyzing and interpolating coastal chemical concentrations

    Genetic variability of Chilean and Peruvian surfclams (Donax marincovichi and Donax obesulus)

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    Exposed intertidal sandy beaches are commonly dominated by surf clams of the genus Donax. In Peru and Chile these bivalves play an important role for artisanal fisheries. Beside that, little is known about the taxonomy, biology, and the clams susceptibility to climatically induced changes. The taxonomic status of the two Donax species Donax marincovichi and Donax obesulus, distributed along the Peruvian coastline, is controversially discussed. As morphometric comparisons reveal no significant differences we possibly deal with a single rather than with two species. Furthermore, our knowledge on larval dispersal allowing gene flow among populations is scarce. Therefore, both putative Donax species were sampled at ten beaches along the coastline from northern Chile to northern Peru. Partial cytochrome oxidase I sequences were analysed in order to estimate the genetic distances between both putative species and to estimate the intraspecific gene flow along the coastline. Region specific patterns and the dependence on recruitment of local stocks are discussed

    Coastline

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    Supply chain temple of resilience

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    In March 2011, an earthquake and tsunami hit the north-eastern coastline of Japan. Honda, Toyota, Nissan and Subaru all had plants in or close to the affected region, and were forced to close them

    Coastal planning in North Shore City, New Zealand: Developing responsible coastal erosion policy

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    North Shore City’s coastline has been subject to intensive development pressure over the last 15 years. In this time, new developments have established along previously undeveloped areas of coastline and existing sites have redeveloped with much larger houses. This paper provides a description of the planning controls that currently affect coastal development and an assessment of the effectiveness of these controls. This is followed by an analysis of the role of local government in controlling future development. Contention arises when attempts are made to control the property rights of landowners to protect their properties from coastal erosion. The impacts of private coastal protection works on the coastline have wider impacts than their immediate location and can influence public perception of the coastal environment. Coastal erosion is a prominent issue for North Shore City and this increase in development has increased the risk to both property owners and potentially the Council. Authorities are concerned that current coastal planning controls do not address coastal erosion to a great enough degree. A methodology for assessing change along the coastline is described and used to identify where planning controls are not being effective by using indicators such as the presence of coastal protection structures and signs of erosion. Alternative policy approaches are identified and evaluated using a cost-benefit analysis framework. It is envisaged that this preliminary cost-benefit analysis will identify policy aspects requiring future in-depth investigation. The practical implications for different policy approaches regarding coastal erosion and private property rights are also explored.coast, erosion, planning, cost, benefit, development, protection, structures., Environmental Economics and Policy,

    Coastline Accuracy Assessment Developed By Using Multi Data Source

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    Coastline Modeling Accuracy Assessment Developed By Using from Multi-Source Data. The coastal regions need to be developed because many big cities in Indonesia are located in these areas. However, it is crucial to determine the distance from the beach that is safe as the requirement for development along the coastal zone. The term of the beach is very closely affiliated with the coastline. The method of determining the coastline continues to be developed to fulfill the many needs related to the coastline. The coastline has a dynamic position. The land contour along the coast and the tide's state become several things that affect the coastline. Therefore, a dynamic model is required to define coastline positioning because both conditions are easy to change. The coastline determination from multi-source data modeling using DEM results is rarely done. In this study, coastline determination uses land height contours combined with sea depth contours and uses Mean Sea Level (MSL) value for vertical reference using the DEM model. The model's accuracy is tested by comparing the coastline delineation model and the Geospatial Information Agency coastline to test the DEM model generated before determining the coastline using this model as the reference. Based on this study, the compared shoreline models and delineation have gaps. This gap might be influenced by the data source, the model's resolution, and the data collection method
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