Identification of desertified and preserved areas in a conservation unit in the state of Paraíba – Brazil

Leandro F Da Silva,Rafael Cámara Artigas,Bartolomeu I De Souza

doi:10.18172/cig.5098

Abstract

The objective of this study is to identify and analyse the main characteristics of areas potentially degraded by desertification and of preserved areas using the Soil Surface Moisture Index (SSMI), alongside the Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI). The study is based on a set of points obtained in the field and from the RGB false colour image for the Environmental Protection Areas (EPA) of the Cariri, in the semi-arid region of Paraíba, using a space-time cross-section covering both rainy and dry periods. The results showed that at all points in Desertified Areas, the main characteristics were a low SSMI, high LST and low NDVI in both periods. The Preserved Areas, on the other hand, presented a high SSMI, moderate LST and high NDVI in the rainy period, with the same characteristics repeated in the dry period for SSMI and NDVI, but with a low LST. Timely identification of these characteristics, both in areas degraded by desertification and in better preserved areas, can provide useful information for future decisions relating to the physical and territorial management of the Conservation Unit.

Highlights

Brazil has the second highest proportion of dry forests degraded by human activity of all the countries in the Americas (Portillo-Quintero and Sánchez-Azofeifa, 2010)
This study aimed to identify and analyse the main characteristics of areas potentially degraded by desertification and preserved areas in a Conservation Unit (CU) for sustainable use, located in the semi-arid region of Paraíba, Brazil, using the Soil Surface Moisture Index (SSMI) proposed by Lopes et al (2011), the land surface temperature (LST) and the Normalised Difference Vegetation Index (NDVI)
The Land Surface Temperature (LST) value calculated for the whole Environmental Protection Areas (EPA) for the month of April varied between 18.5°C and 35.5°C

Summary

Introduction

Brazil has the second highest proportion of dry forests degraded by human activity of all the countries in the Americas (Portillo-Quintero and Sánchez-Azofeifa, 2010). The main threats to this ecosystem are the illegal extraction of wood for energy and for producing fences, as well as the expansion of farming, which has created large areas of desertified land (Castelletti et al, 2003) and has even affected the Conservation Units (CU) created by the state These CUs are defined by the Brazilian Ministry of the Environment (MMA) as territorial units with noteworthy natural characteristics, which serve to ensure the representation of important, ecologically viable samples of the different populations, habitats and ecosystems present in the country and to preserve the existing biological heritage (MMAUC, 2020). They are created in law by the federal, state and municipal governments after technical studies are carried out on the areas of land in question and local people consulted where necessary (MMAUC, 2020)

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