GIS has been defined as an information system that is designed to work with data referenced by spatial or geographic coordinates. In other words, GIS is both a database system with specific capabilities for spatially-referenced data, as well as a set of operations for working with the data. It is also considered as an automated system for capturing, storing, checking, integrating, manipulating, analyzing, modeling and displaying of spatially-referenced data for solving complex planning and management problems.
Planning the coastal zone is in fact a particular instance of spatial planning and as in all spatial plans; maps and attribute data related to those maps play an important role in all phases of the study. As we will see later, an important part of the outputs of the majority of the thematic studies of the project, such as
- coastal boundaries,
- classification of coastal areas,
- coastal erosion and sedimentary cells,
- management units,
- land use and cover of coastal zones,
- Climate, etc.
are all in map form. Hence in these studies digital presentation of maps, their storage, retrieval, spatial queries, individual and joint analysis of maps, overlaying/cross-classifying and generation of new maps is of paramount importance.Considering what was said above, the creation of a geographic information system both at the study/ planning phase and the implementation phase of the ICZM seems to be a necessity. However, although the first is a prerequisite for the second, the role of GIS is not identical in the two phases.
Study/ planning stage
In study/ planning phase the major role of the data base is:
storing a great amount of both graphical and attribute data, and
providing the subject matter groups with the possibility of overlaying, analysis and modeling of those data.
At this phase modeling is essentially for specific needs of study groups such as preparation of suitability maps by combining huge amount of geological, pedological, climatological, social, economical … information (maps), or generating new information such as combining radiation, temperature, relative humidity, wind velocity to produce the potential evapotranspiration map, or modeling the interaction between sea and coastal land at shoreline areas. It goes without saying that the algorithms for these modeling activities will be provided by the study groups and/or by the DHI(the Danish Hydraulic Institute) and not by the GIS experts. DHI, however, will also assist the Iranian group in charge of setting up the GIS.
The Need for Establishment of a Geographic Information System
A Geographic Information System is at the same time a Decision/planning Support System (DSS/PSS); hence it's utility for the management of spatial resources. In a document prepared by the DHI for implementing a GIS system related to ICZM in Iran we read:"…overall objective of implementing GIS/MIS based technology is to provide GIS based Decision Support and Planning Tools to assist in the implementation of the Integrated Coastal Zone Management in Iran." (DHI, 2003, p. 2). "By GIS we mean the integration of all the methods and tools that can be useful to establish a decision support system (DSS) for spatially related problems" (Fedra and Feoli, 1998, p. 4). By establishing such a facility one can analyze and hopefully foresee the consequences of various policies in advance and take better decisions.
Some of the principles prevailing in ICZM such as multi-disciplinary and comprehensive approaches are also included in GIS tools. With the help of GIS's various data (biological, physical, ecological, social, economical, administrative …) and many different views and interests, which are sometimes contradictory (e.g. development at any price versus environmental protection), which could be integrated in a single system and by analyzing them one could reach an optimal (or at least a compromise) solution. This is why GIS has become a key tool for integrated coastal management all around the world. Some of the advantages of these systems are:
- A very suitable technology for storage and management of voluminous spatial data
- A very capable tool for recognition of relations, patterns, and spatial processes
- A suitable methodology to support decision-making and planning
- A suitable approach to produce and display of high-quality maps
Special applications of GIS in the integrated coastal zone management (ICZM) are as follows:
- Establishing conflict maps by mapping and overlaying the activities of various organizations
- Development planning of the coastal areas
- Modeling the interaction between sea and land
- Management of both natural and technological hazards in coastal areas
- Environmental impact assessment (EIA) of projects to be implemented in coastal areas
- A tool for public participation in decision-makings
- Coastal participatory management.
Among the main challenges of GIS applications in integrated coastal zone management are the great dynamism of coasts (in the sense of variability), and fuzziness of coastal boundaries. To overcome these difficulties, the following points should be taken into account:
- Collection of spatial data as precise as possible
- Regular updating of the data, eventually by direct connection to the permanent measurement devices
- Precise data capture and GIS-ready information (with appropriate precision)
- Proper data maintenance.
However, the above mentioned difficulties display at the same time the advantages of the GIS. Since only using GIS softwares and regular updating of the data, one can observe and assess the direction of changes (change in coastal boundaries, erosion of coasts, change in the land use, destruction or on the contrary rehabilitation of significant coastal ecosystems and similar issues, and use them for information and planning). Some of the special applications of GIS are recognition / introduction of Special zones and perhaps particularly sensitive sea areas (PSSA), according to the definition of International Maritime Organization (IMO).