Análise multitemporal do uso do solo no Parque Estadual das Várzeas do Rio Ivinhema e sua zona de amortecimento:subsídios ao planejamento ambiental

Abstract

Natural Protected Areas - NPA - represent the last pristine areas existing in Mato Grosso do Sul state and, therefore, guaranteeing the functionality of these areas through adequate planning becomes a very relevant work. The use of geotechnologies for environmental planning brings more reliability to the process, since it eliminates the subjectivity in the choice of areas and priority actions for the management of the NPA. The mapping of the land use in the area of the Várzeas do Rio Ivinhema State Park - VRIST - and its respective buffer zone - ZA, totaling 292 thousand hectares of mapped area, in three periods – 1998 (year of creation of the VRIST), 2005 (year of management plan conclusion) and 2015 (most recent available data). The maximum likelihood-supervised classification method was used through the GIS Arc GIS 9.3, and legend was established with the following categories: water bodies, forests, wetlands, exposed agriculture/soil and pastures. There were significant changes in soil cover patterns between the three years evaluated, with emphasis on forest areas, which increased substantially both within the PEVRI and ZA during the analysis period. Water bodies decreased in both areas and pasture areas within the Park had a small increase between 2005 and 2015, which would not be expected because of the protection that the VRIST should provide to the landscape and which is not being completely effective. We believe that the recorded fires within the VRIST may contribute to explain this change, as they may have provided conditions for areas with exotic grasses pasture, mainly Brachiaria species, to develop over recently burned areas due its greater competitive capacity. The changes in land use detected during the evaluated period will be used as a basis for a review of the VRIST environmental zoning in the management plan, adapting it to the current situation in terms of the definition of the zones and their respective rules, in order to prioritize the areas that require greater attention in terms of protection and management actions.