Marine Geographic Information Systems:
The Marine environment (oceans and coastal zones) provide some of the earth's most important resources. Managing and mapping this 71 percent of our earth’s water presents a unique set of challenges. The ocean is not accessible thus it requires especially designed instruments to collect the data required which include such as submersibles, satellites, and processing, production, visualization, and interpretation of seafloor maps based on multibeam bathymetry, sidescan sonar, towed camera imagery, and submersible observations, [1] required. GISs are increasingly being used in order to assist in the process of capturing spatial data, storing and retrieving them, processing relevant information from them, and making this information available as required for the researchers as well as for the operators, [2]. The use of GIS, therefore, has great potential to optimize the value of information as a resource within an organization. Marine GIS is being adapted and utilized to assist researchers and organizations in achieving research goals related to oceanographic and coastal problems by facilitating the process of creating and producing geospatial data including coastal shorelines and bottom sea bathymetric.
GIS is playing a vital role in identifying and monitoring effects on these geographical areas which are most likely vulnerable of any marine dynamic processes and human-induced impacts. GIS, as an integrating, analyzing and visualizing tool, vast amount of data is processed; trends and patterns are extracted and eventually visualized using GIS’s 2D and 3D tools to achieve the results powerful software are needed. For instance the ESRI geodatabase and ArcGIS Server allow for new storage and access to data and provide great potential for modeling ocean features, while ArcGIS extensions such as ArcGIS Spatial Analyst and ArcGIS Geostatistical Analyst are utilized to produce sea floor surfaces and contours based on Interpolation. Likewise, there are extensions applicable to create scenarios related to time series visualizations which eventually enable us analyzes information relative to time and location.[3]. As in the land based GIS application, Marine GIS application requires input in the form of a binary or vectorial of oceanographic charts. The use of Nautical Chart at sea by the mariners for navigating at sea is a typical example of the application of GIS in Marine/Oceanographic environment. [4].
Water by its very nature is dynamic. Features associated with water are thus ever-changing and Marine GIS requires up-to-dated measurement technology to acquire the multidisciplinary data input. Eventually, the data can be populated into the databases capable of feeding the production of thematic maps that disclose the pattern of the environments for instance software that can be used in this process can be identified like ERDAS and ENVI [5].The outputs of the process can be diverse which includes develop a strategy to locate locations of concern, tracking invasive species, endangered species, and population changes. There are many issues related to oceanographic chemical properties of the ocean; such as temperature, salinity and fluorescence, the bathymetry data with smooth, shallow sea floor close to the coast; and steep slopes of the continental margin, example the Benthic Terrain Modeler (BTM) is a collection of ESRI ArcGIS-based tools used with bathymetric data sets to examine the deepwater benthic environment; one can create data sets of characteristics such as slope, bathymetric position, and rugosity and then define the relationships between them using a data dictionary that defines, or classifies, benthic terrain, [6]. Acoustic techniques are widely used for surveying of water masses, seabed and sub-seabed resources. Mapping is mainly carried out by seismic, side-scan sonar and multibeam systems that can penetrate through water. Sea surface temperature, for example, can be measured by marine data buoys, ships, oreven satellites, [7]. Marine GIS is now being used to aid decision making, using the interactive mapping applications, marine data downloading tools and associated metadata.