Paulo Roberto Antunes Aranha

Environment, tourism and land use planning – Riachinho Basin, Brazil

Santana do Riacho County, in Minas Gerais State, Brazil, is located in an area known for its natural beauty. The growth of tourism has been the main economic activity of this area. In order to achieve organized land occupation and self‐sustained development, thematic maps of the physical environment were elaborated. Analysis of the water sources supply and recreation have been completed. The risk of water contamination has increased, caused by the increase of tourism activities in this area, added to by local authorities policy. The analysis of all the thematic maps and of the quality of the water sources supply of the area, lead us to develop proposals for land use planning and zoning, adequate for the local conditions and the vulnerability of the underground water contamination. These issues are important concerning the local development and also land use, caused by the tourism activities.

Study of flow in vadose zone from electrical resistivity surveys

Among the indirect methods applied to environmental monitoring, electrical resistivity has played an important role in accessing water flow in the non-saturated zone of the soil and, consequently, aquifer recharge. This work evaluates the influence of some pedo-geomorphologic properties in the infiltration and percolation of water through the superficial soil horizons by means of multitemporal electrical resistivity sections. The experiments were carried out in two areas of distinct pedo-geomorphological characteristics developed on the crystalline basement of southeastern Brazil. The first is situated in a hollow -shaped slope where lixisols predominate; the second, in a nose -shaped slope where well-developed soils (ferralsols ) predominate. The results proved the efficiency of the electrical resistivity method to delimit percolation of tropical soils, even when subtle differences are found in the hydraulic properties of the soil. It was also possible to establish that in the nose slope percolation is faster than in the hollow.