Impactos ambientais do uso e ocupação humana no entorno do reservatório Ministro João Alves (Parelhas/RN)

Abstract

When interacting with nature, human beings generate significant environmental impacts, especially the services offered by ecosystems and which are of great importance for environmental balance and the quality of life of all populations. The use of ecosystem services, as well as human occupation on the banks of reservoirs, has been occurring for a long time due to the practicality of meeting their needs. However, economic activities carried out in the area also cause impacts, which can directly affect the quality of water resources, as well as the biodiversity and aesthetics of the place, damaging the quality of life and health. These impacts can be, in most cases, irreversible if mitigating measures are not taken in time to recover the damaged areas. Therefore, this researchhas as a delimited area for the development of its study the Ministro João Alves reservoir, popularly known as Boqueirão in the municipality of Parelhas/RN. This is of great importance for Seridó, as it has the largest water storage capacity in the region, supplying other municipalities in addition to Parelhas, and also, its water depth is a Conservation Unit. The objective of this work was to identify which ecosystem services (ES) are provided by the Açude Ministro João Alves during the region's annual rainy season and how these services are being impacted. Furthermore, identify the existing environmental impacts in the study area and surroundings caused by human use and occupation. For this, the methodological procedures were: bibliographical survey; field control list; classification of services through CICES (v. 5.1); application of the DPSIR method to assess impacts; identification of areas without dense vegetation on the banks of the reservoir, identification and quantification of the type of buildings and potential purposes, quantification and mapping of roads close to the reservoir. The results reveal the occurrence of new services (even if only at certain periods of the year), where significant impacts affecting these services were identified, and, in addition, the impacts that these services suffer were identified, namely the pollution of bodies water resources, deforestation and the compromise in human andanimal supply are the most visible. Furthermore, there is soil degradation and possibly a compromise in water quality which, as a consequence, causes low vegetation density. The NDVI and SAVI indices indicate that the area surrounding the dam has vegetation considered to be of low to moderate density. Through NDWI, a reduction in the reservoir's water surface was noted. Regarding the number of occupations around the reservoir, they are distributed in around 44 buildings within the 100m area created for the designation of the buffer. Impactssuch as exposed soil, siltation, risk of contamination and increased trophic status of water were also identified in these areas of occupation. To mitigate this damage, it is important to adopt public policies aimed at coexistence with the semi-arid region, together with integrated management applied to the reservoir. It is also worth highlighting the need for inspections, monitoring of water quality and projects aimed at maintaining and restoringthe study area and restoration. The development of a management plan for the construction of a Buffer Zone with appropriate legislation, thus preventing degradation, is also relevant. Therefore, it is concluded that the reservoir suffers impacts at different levels and scales, triggering serious environmental problems in the short term.