TEN YEARS OF LAND USE AND LAND COVER CHANGES IN NEGRO RIVER WATERSHED, RIO GRANDE DO SUL, BRAZIL: 2003-2013
ISBN 978-85-88783-11-9
Authors
1Branco, V.; 2Moreira, D.; 3Schafer, A.
1FEDERAL UNIVERSITY OF PAMPA Email: viviantabranco@gmail.com
2SENAI CIMATEC Email: davidson.moreira@gmail.com
3FEDERAL UNIVERSITY OF PAMPA Email: alexandro.schafer@unipampa.edu.br
Abstract
This paper presents the results of the mapping of the changes in land use and land cover of the Negro River watershed, in Rio Grande do Sul, Brazil, in the last 10 years, using images of Landsat Data Continuity Mission (LDCM). We used images of Landsat 7 and Landsat 8, in 2003 and 2013, respectively. As the study area lies between two adjacent Landsat sites (orbit-point 222/82 and 223/82), the first step of the work consisted of a search for satellite images for the two sites which were obtained within four-week periods. The selected scenes were imaged on January 6 and 29, 2003, for Landsat 7, and April 15 and 22, 2013, for Landsat 8. Seven types of land cover and land use were defined for supervised classification: water, field, agriculture, forest, reforestation, urban, and with no classification. The method used for the classification was the maximum likelihood. To facilitate the visual identification of the different types of LULC in the "training" stage, we performed five field trips to the study area, aiming to settle doubts about the targets. Findings show that in the Negro River watershed, the predominant field area (55.9% in 2003 and 50.9% in 2013) decreased about 5% in those ten years. The forest area decreased 8.59% and the reforestation area increased 2.1% in this period. The agricultural area increased 16.4%, occupying 34.9% of the area of the watershed in 2013, and the urban area increased 0.1%, representing 1.0% of the area of the watershed in 2013. Based on the results presented, there was an increase in the catchment areas in the agriculture areas, areas previously occupied by fields, forests and reforestation. The growth of agricultural areas should, for the most part, increase soybean cultivation in the Negro River watershed.
Keywords
Negro river watershed; LULC; Change