Assessment of land cover change in Portugal from 1985 to 2000 using landscape metrics and GIS Sérgio FREIRE and Mário CAETANO Proposed in 1985 by the European Commission, the CORINE Land Cover (CLC) is a geographic land cover/land use database first produced in Portugal for the years 1985/86/87. The recent improvements in the original database and its update for the year 2000 provide the first opportunity in Portugal to accurately characterize land cover in two different time periods and to assess change using two products with identical technical characteristics. Using NUTS as main spatial reference units, landscape metrics are computed for both periods and compared in order to investigate changes. Urbanization relative to the coastline is also characterized. Results indicate that the Portuguese landscape is very rich and dynamic, diversity and fragmentation of land cover have generally increased, and that urban pressure is heavy along the coast and keeps rising. Despite high change rates, overall land cover of Portugal is still largely dominated by forest and agriculture. KEYWORDS Land cover change, CORINE Land Cover, landscape metrics, GIS, Portugal. INTRODUCTION Information on land cover and land use (LCLU) and the way it changes over time is crucial for environmental assessment and for informed decision-making. Making this information available in digital map form further increases its value and usefulness for integration with other geographic information and conducting spatial analysis. However, subjective decisions are involved in the production of LCLU databases, and these are heavily dependent on chosen or available source data and technical characteristics, such as scale, minimum mapping unit (MMU), and classification system selected. An important consequence of these constraints is that even databases produced for the same area and period most often will portray the landscape differently. Therefore, rigorous assessment of LCLU change should be based on maps for different dates but having the same technical characteristics and produced with similar methods. It is generally assumed that Portugal has a diverse and dynamic landscape, but lack of reliable and comparable data prevented the quantification and characterization of these changes. The recent completion of the CORINE Land Cover (CLC) databases for Continental Portugal provides a good opportunity to overcome these difficulties [8]. These products map LCLU in the years 1985/86/87 and 2000 using similar source data, methods, and have the same technical characteristics. However, the fact that satellite imagery acquired in the years 1985/86/87 is the source data for the first portuguese CLC database makes it inappropriate to calculate annual change rates. Also, assessing changes in this period is especially interesting since important transformations with an impact on LCLU seem to have taken place in Portugal, many due to the country joining the European Union in 1986. The CORINE Land Cover 2000 Project (CLC2000) in Portugal was carried out in the context of the IMAGE and CORINE Land Cover 2000 (I&CLC2000) initiative from the European Commission. The main goal of this initiative is to map the land cover of Europe in 2000 by updating the previous land cover maps [6, 10]. As a result of the CLC2000 Project in Portugal, three land cover databases were produced for Continental Portugal: 1) the CLC90-R database, which is an improvement (both geometric and thematic) of the first CLC product of 1985/86/87, known as CLC90; 2) CLC2000 database, for the year 2000; and 3) CLC-changes, the database of changes that occurred in the