Diagnóstico do solo, água e vegetação em um trecho do rio Chafariz – Santa Luzia (PB)

Abstract

Deforestation, fire, cattle raising and mining are economic activities that contribute to remove the native vegetation, including the riparian vegetation. These activities result in soil runoff directed to riverbeds and dams, with negative environmental impacts. Most rivers in the semiarid region of Northeast Brazil are intermittent: its river bed sand is exposed during the dry period, while the water overflows the river banks during the rainy season, carrying sediments to water bodies, and sometimes carry salt to lowland sites, causing problems to plant productivity. The semiarid region in Northeast Brazil, known as “Polígono das Secas”, shows space-temporal rain irregularity, and this is of great concern to regional development. Decreases in agricultural productivity are a result of soil erosion and reduction of organic matter levels in soil after removal of native vegetation and higher soil exposure to abiotic factors that intensify environmental degradation. This situation is aggravated by the low education level of the population, unbalanced land distribution, socio-politic- economical discrimination, as well as climatic factors, such as the annual dry season. Santa Luzia municipality is located in the Borborema meso-region and in the Oriental Seridó micro-region of Paraíba. Its economy is based on trade, mining, and subsistence agriculture and cattle, goat and sheep raising by small farmers. However, little is known on the environmental impacts caused by these activities. This study was carried out in Santa Luzia municipality (PB), with the objective to analyze the environmental degradation of a 6 km-long part of Chafariz River. Soil, water and vegetation characteristics were used to make a diagnosis of the degradation of these natural elements of the local landscape.