Sequential Gaussian Simulation of Uranium Spatial Distribution – A Transboundary Watershed Case Study

The main purpose of this work is the uranium spatial distribution patterns in groundwater, within the Águeda river transboundary watershed (Portugal-Spain). Mineral resources occur distributed throughout the watershed, mainly sulphide and uranium minerals. Sixty-five groundwater samples were analyzed. Geostatistical modeling was used, throughout conventional variography and Sequential Gaussian Simulation algorithm, to model the groundwater uranium spatial distribution. A hundred simulations, differing in their initial random-number seed, were performed. Spatial uncertainty evaluation allowed the definition of future monitoring and sampling strategies as well as the measurement of remediation possibilities. Uranium hot spots are strongly embedded in the central area (Ciudad Rodrigo).