Land use at the margins of the Atibainha Reservoir, cantareira water system (SP): Conflict with the current legislation

Abstract

The management of hydrographic basins for water supply involves land use diagnose for environmental quality assessment and liabilities resulting from practices that can be harmful to water resources. The identification of different forms of land use in Permanent Preservation Areas (PPA), as defined in the New Brazilian Forest Code (Federal Law 12.651/12), is necessary for the assessment of expected impacts on water quality. The objective of this work is to comprehend territorial dynamics in the Atibainha Reservoir tributary basin, located in Nazaré Paulista and Piracaia (SP). GIS techniques were applied to define the PPA size on the margins of the reservoir, adopting widths of 100 meters for rural areas and 30 meters for urban areas. Remote sensing techniques were applied to map land cover through the automatic supervised classification. Land cover mapping showed the presence of 55.9% native forest, 29.3% undergrowth, 6.9% reforestation, 4.5% water and 3.4% of area built in the tributary basin. 98.5% of the total area of the reservoir (1596.24 km2) corresponds to rural areas. The marginal Atibainha Reservoir PPA is composed of 58.9% native forest, 33.5% undergrowth, 5.7% built-up area and 1.9% reforestation. A growing urban development of homes and clubs around the dam is observed, affecting the PPA in varying alarming ways, which leads one to consider the urgent need of public policies for the Atibainha Reservoir.