Remote sensing methods for assessing coastal environmental damage

Remote Sensing (satellite Images) in Coastal Environments

Remote sensing in costal environments: Methodology and uses

The methods for using remote sensing in coastal environments

Remote sensing "involves the measurement of electromagnetic radiation reflected from or emitted by the Earth's surface and the relating of these measurements to the types of habitat or the water quality in the coastal area being observed by the sensor" (Edwards 2009). "Remote sensing provides a synoptic portrait of the Earth's surface by recording numerical information on the radiance measured in each pixel in each spectral band of the image being studied. To create a habitat map, the operator must instruct the computer to treat certain reference pixels as belonging to specific habitats. The computer then creates a 'spectral signature' for each habitat and proceeds to code every other pixel in the image accordingly, thus creating a thematic map" (Mumby & Green 2009).

The results of using remote sensing in coastal environments and the role of remote sensing in changing the understanding of coastal environments

The use of remote sensing to assess the damage done to costal environments has become increasingly important, and has been facilitated by the greater ease of use of computer-based self-tutoring packages. Remote sensing is a relatively unobtrusive, zero-impact, yet comprehensive method of assessing an environment's current conditions and future needs. For example, it has recently proved effective in understanding the damage done to the coastal and marine environment of the Gulf States. This is critical "given the important commercial interests" in the region's natural resources combined with the potential that exists for the exploitation of the "fragile" coast (Sudarshana 2009).

The use of airborne and space-borne imaging sensors over the last two decades has also played a role in mapping areas difficult to reach by sea or land, such as the complex landscapes of French Guiana (Polidori, 2009, p. 627). "The permanent evolution of this environment is a concern for decision makers, since the population and the economic activity of this region are concentrated along the coast. Sea defense operations and coastal infrastructure management (polders, harbors), as well as ecosystem preservation programs, require a better understanding and a regular monitoring of the coast line evolution" (Polidori, 2009, p.627). From an environmental perspective, the use of remote sensing does not disturb the local population, or the flora or fauna, yet presents an environmental snapshot of the area that can be analyzed, so recommendations can be made as to how to improve the balance between inhabitants and the natural world.

The future opportunities of remote sensing in coastal environments

Because of its cost-effective nature, in contrast to land-based sensing, remote is likely to become more popular in the future. Granted, habitat-mapping can be an expensive undertaking. However, after the initial set-up costs, "using remote sensing to augment field survey is the most cost-effective means of achieving outputs for scientific and management purposes. Four types of cost are encountered when undertaking remote sensing: (1) set-up costs, (2) field survey costs, (3) image acquisition costs, and (4) the time spent on analysis of field data and processing imagery. The largest of these are set-up costs, such as the acquisition of hardware and software, which may comprise 40 -- 72% of the total cost of the project depending on specific objectives" (Mumby, Green, Edwards & Clark 2009). The major cost is the GPS (global positioning software) needed for the system. However, once the technology becomes ubiquitous, costs will likely decrease, in contrast to the continued maintenance costs of previous ground and sea-based operations.