Spatio-temporal dynamics of land use changes of an intense anthropized basin in the Brazilian semi-arid region

Abstract

The temporal dynamics of land use and land cover (LULC) changes affect natural resources and biodiversity on a local and global scale. The negative impacts of LULC changes can be enhanced in arid and semi-arid areas, where vegetations are more sensitive to changes due to limited water availability. The present study aimed to explore the detailed spatio-temporal LULC changes in the Jaguaribe River basin, Ceará state, Brazil. Specifically, we aimed to identify the dynamics of LULC changes from 1985 to 2018, including the main LULC conversations and the sub-basins that presented the most intense dynamics. For this, we used annual LULC maps generated by the national Mapbiomas project. The LULC conversions were determined through cross-tabulation analysis and pixel comparison analysis. Our results indicate that in the last three decades there was a significant conversion of the natural vegetation Caatinga (Arboreal and Herbaceous) to agricultural and livestock areas, showing that the anthropic activities are the main factors behind the historical landscape changes in the Jaguaribe River basin. The Middle Jaguaribe and the Lower Jaguaribe sub-basins were the most affected by LULC changes during the study period. While the LULC changes in Middle Jaguaribe sub-basin reveal that this area has been impacted by anthropic interference with similar areas of pasture and the caatinga class since 1985, the Lower Jaguaribe sub-basin was continuously impacted mainly by the expansion of the annual and perennial culture and reduction of natural vegetation areas. The Lower Jaguaribe sub-basin had a higher percentage of altered areas, LULC classes per pixel and LULC changes during the study period. The spatio-temporal analysis presented can orient planning actions to conserve natural resources and preserve the biodiversity in this semi-arid region of Brazil.