VARIATION OF THE OCCUPIED AREA BY RIPARIAN ZONE ACCORDING TO CONSIDERED WIDTH

Resumo

Considering that the riparian vegetation provides many "ecological services" and such services vary according to this width, in this study we surveyed some morphometrical parameters of the Sorocaba city, as well as we estimated the area and respective percentage occupied by riparian zone according to the riparian buffer width. The considered width values were: 30, 45, 60 and 90 meters. Two digital cartographic bases were used: hydrographic and headwater maps. These two maps were joined and the maps containing the buffer zones were created. Considering 30 m width, the buffer zone occupies area of 92.2 km2, corresponding to 20.4% of the study area. For 45 m width, the area was 118.9 km2 (26.1%). For 60 m width, the area was 141.2 km2 (30.9%) and for 90 m width the area was 199 km2 (43.7%). Additionally, it was possible to create the Riparian Buffer Index that permits to estimate, using the total channels length, the destined area to be reforested according to the desired riparian buffer width, as well as the costs of this project.