Índice de risco a erosão e mapeamento das áreas de risco por erosão de solo em Natal-RN

Abstract

The Municipal Risk Reduction Plan in Natal-RN does not cover the whole municipality and is out of date for 10 years, being the method used difficult to update due to its subjective nature. The present work aimed to map the risk areas to soil erosion throughout the municipality using a proposal of index focused in geoprocessing. For that, a method of analysis of the natural fragility of the soil was adapted to include data obtained by Geographic Information Systems. A geoprocessing program was used to produce thematic maps in the 1: 100,000 scale. These maps were used as indicators for creating the Erosion Risk Index from the arithmetical overlap. The Map of Risk to Erosion generated covers the whole territory of the municipality and identifies the risk of soil erosion by means of 5 classes, according to the index developed by this work. In order to ratify the method, field visits were carried out to verify the identified risk areas and to carry out photographic records, adding 17 visitor areas in 8 neighborhoods. The work concluded that the Erosion Risk Index measured the risk areas to soil erosion, including in a way that can be updated when inserting new data. It also concluded that the Erosion Risk Map can be used by local management as a risk zoning to guide priorities of the risk management for natural disasters due to soil erosion.