SECTION 14
From the previous sections it will be apparent that the form and methods of data collection are of great importance to a marine resource mapping program. The collection phase may include a variety of techniques from relatively simple and inexpensive data gathering exercises, such as the deployment of field personnel equipped with felt markers and base maps, to the complex operations associated with data collection from remote sensing platforms (satellites, fixed wing aircraft and helicopters). The information collected can be stored in the conventional manner on hard-copy maps, or it can be entered into the computer of a geographic information system (GIS) and stored in a digital form.
Utilization of these more sophisticated techniques is certainly not essential for the development of a marine resource management plan. They should be considered, however, since the more elaborate data collection, storage, analysis and presentation procedures are now becoming readily available.
The automated production of topographical maps and hydrographic charts was briefly referred to in Section 5. The rapidity of research and development in this field can be appreciated by reviewing the proceedings of recent automated cartography symposia. Limited investment mapping systems, which consider the automated production of thematic maps, are currently available with modestly priced hardware (computer, terminals, plotters, etc.) and software (computer programs).
Because of their complexity, earth resource analysis (e.g., fisheries) and land use planning require the investigation of the relationship of large volumes of detailed information, hence the demand for Geographical Information Systems (GIS). The essential elements of an automated GIS are indicated in Figure 14.1.
A Geographic Information System permits automated inventory and management of geographic (spatially related) data such as that contained on maps, charts and other graphical representations. A GIS uses a combination of hardware and software to input, store, analyze, manipulate and output graphic and text data in a variety of formats. There are four main activities involved in this process:
i) Input: User documents such as maps, charts, aerial photographs, tabular or text data are entered into the system via a digitizing table, through keyboard terminals or from existing digital media using a number of specially developed interfaces. Alternatively, a map may be scanned, rather than manually digitized, with a laser or optical scanner;
ii) Processing: Once data is entered into the system it can be processed, stored, analyzed, synthesized or queried to create an unlimited range of products and to answer questions regarding the data;
Figure 14.1 The essential elements of an automated Geographic Information System (GIS). (After H.J.G.L. Alders, 1980)
iii) Output: Output can be generated from the system for temporary viewing on a terminal (colour or black and white), or as hard copy for distribution or publication using a printer, plotter or other hard copy devices;
iv) Communication: With the aid of recently developed protocols, both alphanumeric and graphic data can now be transmitted over dedicated telephone lines with relative speed, accuracy and economy.
Special software and hardware are required components of a GIS. The software can be purchased and used on the following hardware:
| i) | digitizing table; |
| ii) | colour graphics display terminal(s); |
| iii) | video display terminal(s); |
| iv) | micro, mini or main frame computer(s); |
| v) | plotter; |
| vi) | line printer; |
| vii) | disk drive(s); |
| viii) | tape drive(s); |
| ix) | hard copy unit(s). |
Figure 14.2 indicates a typical hardware configuration. A GIS is especially suited for processing and handling dynamic (i.e. frequently changing) data, the subject of thematic resource maps. Most GIS systems are similar in configuration but subtle software differences make some systems more versatile than others.
Interfaces have been developed which permit a GIS system to receive and transmit data from/to other systems. In addition to its mapping function, the computer of a GIS can be used in a “number crunching” capacity for stock assessment and other statistical needs of marine resource management.
When the concept of a GIS has been accepted as an integral component of marine resource mapping and management, the development of a fully integrated marine resource management system becomes a possibility. The components of such an interfaced system, in addition to the GIS, might include (Figure 14.3):
i) Database management system, which can track and index data or information within the system components;
ii) Image analysis system, which can provide timely new or updated data collected from remotely sensed imagery;
iii) A storage system, which can store, access and display graphic documents such as marine charts which do not require constant updating. Microfilm or laser videodisc systems can fulfill this role.
The task of interfacing such diverse systems is currently in progress and although many of them cannot yet be described as “user friendly”, the trend towards automated marine resource mapping and management is inexorable.
Figure 14.2 Typical hardware configuration for an automated GIS.
Figure 14.3 Components of an integrated resource management system.
