Environmental diagnostic and temporal analysis of the suitability of the land use and land cover in the “Ribeirão dos Marins” basin, Piracicaba - SP

Author(s)

Catia Andersen Casagrande

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2005-09-28

Examining board members

Maria Victoria Ramos Ballester; Emilia Hamada; Reynaldo Luiz Victoria

• Advisor: Maria Victoria Ramos Ballester

Abstract

The environmental diagnostic and the analysis of the occupation suitability allows the identification of more critical areas according to its degradation level, being extremely important for the establishment of preservation, conservation and recovery measures. An environmental diagnostic and suitability analysis of the land use and land cover of the “Ribeirão dos Marins" watershed was carried out, considering the land cover changes through time and its influence on the water resources, in respect to the current environmental legislation, using geoprocessing techniques. Analysis of the changes in the watershed, the suitability of the land use and land cover, and the relation among some aspects considered in this study were performed. The analysis involved aspects related to water quality, land use and land cover, landscape structure, erosion risk, land use capability and suitability of the land use in relation to erosion risk limitations, and environmental legislation, including Permanent Preservation Areas (PPAs). It was observed that the water resources of the basin are being degraded, the land use and land cover is inadequate and landscape fragmentation is underway. Potential contamination sources of the watershed’s natural resources were identified, compromising the water quality used for horticulture irrigation. Urbanization is the main factor influencing water quality, although pastures and sugar cane predominated in the watershed in 1962, 1995 and 2000. A 6.5 % increase in urban area was verified in the last 38 years. Forest fragments also increased in the basin (4.5 %); however, this increase was less intense in the headwaters, were lower soil protection yields a high erosion risk. Areas classified as suitable with restrictions and unsuitable, more critical due the high erosion risk, corresponds more than 12 % of the basin but are reducing through time. Irregular situations regarding the environmental legislation and preservation were detected in the watershed. Land use and land cover are inadequate in a large extent of the PPAs around of the watercourses, mainly for not attending the environmental functions defined by the Forestry Code. These areas are predominantly covered by pastures. An effective environmental policy is necessary, which must consider suitable environmental planning, guiding the occupation of the basin and the adoption of mitigation measures. (AU)