IMPLEMENTAÇÃO DO SISTEMA INTEGRADO DE GESTÃO E CONTROLO EM PORTUGAL

Abstract

The development of geographic information systems in Portugal is at the threshold of embarking on an ambitious program based on digital information technology, designed of On the implementation of the agricultural field panern creation related 10 the integrated system in Portugal. This project deals with two complementary subjects: the first one corresponding to the production of a cartographic representation that can be used 10 identify and locate the agricultural parcels in the framework of the integrated system; the second one deals with the space decomposition and its use to geocode these parcels. There is a close relationship between these two aspects mainly because the level of interpretability of the cartographic representation can enable (or not) its use by both the farmers and the Portuguese Administration. The SIGC database has been created for monitoring the land cover all over Portugal. To update this database is a priority task now. A specific integrated geographic information system was adopted. Digital orthoimages were used to extract segments of boundaries of parcels to arrange them as a structure of closed polygons, with cach polygon corresponding to a separate parcel. All these elements are correctly crossreferentiated. The associated database contains, for each polygon the corresponding parcel attributes (geocode, area, internal id) which is joined to the database created by farmers declarations. The photo-interpretation work was needed to divide the whole area of the orthophotos into homogeneous zones of forest, arable lands and mixed areas. Later, these zones was subdivided to create a second layer of information using agricultural limits and physical limits, whenever they do not cross agricultural parcels, in order to obtain ilots with a defined size and number of parcels. The ilots should have a good degree of homogeneity and a good time stability. These two layers (parcels and ilois) ofinformation were overlayed to produce a new code for parcels that are inside in the same ilot.