Urban expansion in the Campos do Jordão Plateau: geomorphological diagnosis for planning purposes

Abstract

Part of the main block of the Serra da Mantiqueira, the Campos do Jordão Plateau has been exposed in recent decades to the pressures of a continuous and desorderly urban expansion, which increased the inherent unstable natural conditions of the tropical plateau. Quaternary evolution under high altitude (up to 2050m) conditions developed a tropical montane landscape system, the altos campos geosystem, characterized by a structure in precarious equilibrium, extremely vulnerable to inadequate land use and prone to urban environmental hazards. Knowledge of the geomorphical characteristics of the site is of the utmost importance for planning urban development and deliberate interferences in the steep high relief of the plateau. Mapping of urban evolution (1973, 1982, 2000) clearly shows the intensification of urban growth in the last decades and its effects in the decharacterization of the original vegetation mosaic. Detailed geomorphological mapping (1:8000) of three sampling areas in the more intensively urbanized Capivari/MogiGuaçu Valley was based on field work and the interpretation of aerophoto and satellite images. The geomorphological compartments identified in previous investigations at the altos campos as dynamic units characterized by specific landforms, materials, soils, vegetation and processes, constitute the basis of the diagnosis. Ten diagnostic units were defined, each one with specific aptitudes in relation to risks associated with urban development. These unities were finally ranked in three classes according to the vulnerability to erosive processes and fitness to urban development.