Spatial modelling of groundwater recharge areas in a Guarani Aquifer System (SAG) outcrop region in Brotas/SP-Brazil

Abstract

In areas of groundwater recharge the soil water infiltration at depth is essential for the demand does not overstep the water availability. The different soil management methods due its occupation will pressure on this resource and generate differently responses in their ability to recharge. Modeling the spatial variability of physical and hydric soil proprieties is a key issue for the success of soil management system that allow groundwater recharge. Through geostatistical methods you can access these information and map areas favorable or unfavorable for recharge within a spatial prevision model that brings together several variables that explain groundwater levels variation. This research aims modeling the different response levels of the Guarani Aquifer System (SAG) as a function of soil use and changes in physical-hydric soil properties in the Ribeirão da Onça watershed, Brotas/SP-Brazil. From a survey of physical-hydric soil properties as texture, grain size, hydraulic conductivity and penetration resistance, associated with a collection of temporal series of groundwater levels and classified satellite images in the watershed, it is intended to test the regression kriging methodology to create a spatial prediction model able to generate maps representing areas with higher and lower levels of infiltration and water movement in soil, and its influence in the recharge. The mapping procedure will be performed to establish relationships between the cultivations of sugarcane, eucalyptus, citrus and pasture, and recharge in the area during an hydrological year. From the spatial description of the recharge phenomena is intended to generate a prediction model that helps in decision making in watersheds management plan and sustainable use and protection of groundwater resources in vulnerable areas such as outcrops of the GAS. (AU)