Crop surface dynamics through remote sensing in Catalonia in the period 1987-2012

Abstract

This paper presents a study of the changes that occurred in Catalonia during the 25 years between 1987 and 2012 in the areas devoted to agriculture. This study is based on data from the six editions of Land use and land cover map of Catalonia (MUCSC, from Catalan) obtained through automatic classification of Landsat satellite imagery, highlighting the advantages of this type of information for the study of large land extensions in long time series. The results show that the average area occupied by crops in Catalonia over these years is 32 %, with rainfed crops predominating over irrigated crops (24 % and 8 %, respectively) and herbaceous crops over woody crops (20 % and 12 %, respectively). The area occupied by this cover has been decreasing during the study period at an average rate of almost 8,000 ha/year, although the average acceleration (-47 ha/year2) seems to indicate that the regression process has been slowing down, particularly in recent years. This loss mainly affects rainfed crops, while irrigated crops remain fairly stable, and it is mainly due to the abandonment of croplands and the subsequent renaturation of fields, as well as to the increase in urbanized areas (in this case particularly in the central coast regions). Despite the losses, new cropland is appearing in the areas of Lleida and of the Osona and Empordà regions.

Keywords: remote sensing, Landsat, MUCSC, crops, land cover changes.