Identificação de áreas potenciais à vulnerabilidade ambiental na microbacia do Talhado, Santa Luzia - PB.

Abstract

The edafoclimatic particularities that occur in the Brazilian semi-arid, together with the predatory exploitation model present in the region, contributes to the vulnerability to which is exposed the local population, increasing the risk of environmental disasters. The aim of this study was to determine the environmental vulnerability index (EVI) and identify the socioeconomic, environmental and drought vulnerability in the micro-watershed of Talhado, in the municipality of Santa Luzia – PB. The area of study is circumscribed between the geographical coordinates: 36º 54’ 39” to 36º57’07” west longitude and 6º59’08” to 7º02’12” south latitude. For the application of the methodology, the environmental vulnerability index was generated by the addition of the following information plans: normalized difference vegetation index, topographical factor, current land use, permanent preservation areas and restricted use; which were created using a geographical information system, which encompassed the AutoCad 2015 and Idrisi Andes, version 16.0. For the study of the social, economic, technological, environmental and drought vulnerabilities, the data was collected by means of structured questionnaires, applied at family unit level, in variables identified by codes which surveyed the present situation of these factors in the studied community. To calculate each factor’s vulnerability percentages the mode and the maximum and medium values of each variable were used, inserted in the linear equation, determined for each case. From these percentages, the vulnerability was classified as being low, moderate, high or very high. The results showed that, 581.17 hectares (49.94%) of the micro-watershed presented moderate vulnerability, followed by areas of low and very low vulnerabilities, corresponding to 541.45 hectares (46.53%), while 41.08 hectares (3.53%) varied from serious to very serious. A very high level of socioeconomic vulnerability was found (50.4%). For the environmental factor it was of low magnitude (13.08%), as for the droughts, there is also a very high level of vulnerability (48.08%). These results indicate that urgent solutions are necessary so as to avoid the advance of the vulnerability and mitigate its negative impacts on the environment and the local population.