Morphometrical analysis and land use of the Arroio Candiota watershed, RS, Brazil

Abstract

The Knowledge of the natural and anthropogenic factors at watershed scale is crucial to management of water resources, considering that the river systems are organized hierarchically. In this sense, this study aims to describe the morphometric characteristics of relief and drainage network as well as land use in the Arroio Candiota watershed, RS, Brazil. For this, 26 catchments were selected to analyze 15 morphometric variables and eight land use classes. In general, the catchments showed low drainage density and streams with low sinuosity. Circularity ratio, relief ratio, slope and topographic factor were inversely correlated with the catchment area. Therefore, the smaller catchments tend to have greater potential for erosion in their main channel and increased susceptibility to flooding, because it is more likely the entire catchment be achieved simultaneously by rainfall. Most of the Arroio Candiota watershed (59.31 %), mainly its eastern portion, is occupied by natural vegetation. Mining and forestry are associated with the regions nearby of headwaters of streams while agriculture and degraded prairies are distributed closer to the main course of the Arroio Candiota. This study demonstrates that the morphometric characteristics and land use vary spatially in Arroio Candiota watershed and the distribution of some human activities is related to natural features such as relief and water availability.