Avaliação multitemporal do uso e cobertura da terra na microbacia hidrográfica do arroio Lajeado Grande em Alegrete/RS.

Abstract

This study aimed to make a multi-temporal analysis of use and land cover in the watershed of Arroio Lajeado Grande in Alegrete municipality in the state of Rio Grande do Sul. It was found the use and land cover in the 1984 period, in 1994, 2004 and 2010, thus determining the change of use and land cover over the time series. Use maps were prepared and land cover and cross between the years 1984, 1994, 2004 and 2010. Being drafted in ArcGIS 10.1. The evaluation of the use crossings and land cover and the cross-tabulation provided the quantification of changes in the study area. In the years 1984 and 1994 was noted the increased native forest, showing the level of conservation of the study area, the native field expanded with the decline of agriculture. From 1994 to 2004 the native pasture reduced significantly with expansion of agriculture and pasture, and from 2004 to 2010 the decrease of native forests, increase in native grassland area and decrease in pasture area. Thus concluded that the river of Lajeado Grande creek watershed had his change in land use and land cover through anthropogenic, especially in reforestation and the use in agriculture and the methodology used in the work met the objectives proposed in the study.