TITLE:
Geostatistical Methods for Lithological Aquifer Characterization and Groundwater Flow Modeling of the Catania Plain Quaternary Aquifer (Italy)
AUTHORS:
Enrico Guastaldi, Andrea Carloni, Giovanna Pappalardo, Jacopo Nevini
KEYWORDS:
Alluvial Aquifer; Lithological Simulation; Geostatistics; Numerical Modeling; Sicily
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.4,
March
27,
2014
ABSTRACT: Sedimentary
heterogeneity conditions of Catania Plain quaternary aquifer (CPQA), the wider
alluvial multi-aquifer system of Sicily, were rebuilt to simulate and quantify
groundwater flow. Transition probabilities based on a Markov Chain (MC) and
Sequential Indicator Simulation (SIS) are the structure-imitating simulators
utilized for generating stochastic distributions of hydraulic conductivity
fields of CPQA, basing on borehole data: plausible equiprobable solutions of
the complex geological structure of the CPQA were simulated. This study
highlights that the choice of geostatistical simulation method plays a
fundamental role in predictive scenarios for groundwater resources managing of
CPQA. Indeed, simulated characteristics of the sedimentary heterogeneity
constituted the basis of finite difference models for simulating the
groundwater flow of CPQA. In heterogeneous systems such as CPQA, SIS may be
inadequate for reproducing the macrostructures. Instead, MC adequately
reproduced spatial connection of lithofacies, representing a more realistic
solution dealing to the proposed geological model of CPQA. MC and SIS models
were utilized to both assess the uncertainty of the generated hydraulic
conductivity fields of CPQA and predictions about its behavior under normal
stress conditions induced by urbanization. The calibration of CPQA groundwater
flow models based on MC and SIS simulations allowed to achieve a realistic
feedback about the quality of the geostatistical reconstructions of the
geological heterogeneity field.