Drainage dynamics in karst plateaus from Betari River, Ribeira Valley - SP

• Grant number: 09/05115-5
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2009
• End date: April 30, 2012
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: José Antonio Ferrari
• Grantee: José Antonio Ferrari
• Host Institution: Instituto Geológico. Secretaria de Meio Ambiente, Infraestrutura e Logística (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

The mechanisms of genesis and development of karst aquifers lead to a highly discontinuous and heterogeneous medium. Hydrologic models based on the notion of representative elementary volume can't be used in karst. On the other hand, in karst aquifers the flow of the catchment area is often concentrated in a single spring, and this characteristic has stimulated the use of the system analysis approach to understand their properties. The principle of this technique is to consider the aquifer as a filter which transforms the input signal into an output signal. The degree of transformation of the input signal therefore provides information about the nature of flow in the system. In this analysis, variables related to the relief of recharge zone and the spatial arrangement of subterranean drainage also must be considered. This research aims at monitoring simultaneously some karst aquifers from Vale do Ribeira, in order to understand how the different system's components operate in the hydrodynamics and in the material flow registered in springs. In order to perform the comparative analysis the following procedures will be executed: a) monitoring of flow rate and material flow in the springs; b) rainfall monitoring of recharge areas; c) tracer tests to identify the geometry of subterranean network and solute transport dynamics; d) geomorphology analysis of recharge zone. The infiltration dynamics of the epikarst zone in the recharge area will be investigated in one of the systems. Statistical tools for time series analysis will be used for hydrologic characterization of the systems and to quantify the several pulse-trains relations. Hydrologic parameters in tracer tests will be obtained by the method of moments. This research will provide fundamental parameters to sustained development of karst aquifers and management of conservation areas. (AU)