APPLICATION OF GIS TO CEPHALOPOD FISHERIES: WORKSHOP REPORT

摘要

Geographical information systems (GIS) are implementations of computer-based techniques for managing, mapping and analysing geo-referenccd data. GIS technology integrates common database operations, such as queries and statistical analyses, with the unique visualisation and geographic analysis benefits offered by maps. Such systems can yield information, on the spatio-temporal structure and relationships of variables, which would otherwise not have been apparent in the source data sets. The domain of GIS concerns geo-referenced data, integration and analysis, which converts raw data into meaningful information and supports management decisions. The first step is the measurement of natural processes from spatial and temporal perspectives. These measurements are then related to features, attributes and relationships in a GIS database, stored in digital form in a computer database, and can be linked to features on a digital map. The data can be of five main types: points, lines, and polygons (vector) as well as pixels and voxels (raster). The combined analysis of collected measurements from multiple datasets, to produce new (derived) data and to discover new relationships, by numerical manipulation and modelling, comprises the main core of GIS techniques. It is the combined analysis of GIS that provides meaningful information on natural processes. The communication medium of GIS analysis and output is the depiction of the measured or analysed data in some type of display, e.g., maps, graphs, lists, reports or summary statistics.