Banca de QUALIFICAÇÃO: Mariana dos Santos Diniz

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Mariana dos Santos Diniz
DATE: 25/08/2023
TIME: 14:30
LOCAL: on line (teams)
TITLE:

Probabilistic-Regional Modeling of Contaminant Transport in Unsaturated and Heterogeneous Porous Media: Three-Dimensional Mapping of Spatiotemporal Dynamics in Contaminated Areas

KEY WORDS:

Contaminant transport, Unsaturated soils, Heterogeneous soils, Numerical solutions, Analytical solutions, Probabilistic methods, Probabilistic-regional mapping.

PAGES: 51
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

As a result of industrialization and economic development over the past centuries, the world has faced larger environmental issues with shorter return periods. Of particular note in Brazil are the ruptures of the Mariana dam in 2015, and the Brumadinho dam in 2019. However, lower intensity environmental impacts and/or consequences arising from sources of contaminants, such as landfills, controlled dumps, and agricultural areas under pesticide application, should also be prioritized. In the long run, they are characterized by resulting in adverse effects that can potentially be even more harmful than those resulting from environmental disasters.
Understanding solute transport at the field scale allows for quantifying the flow of contaminants passing through a given plane, estimating the effects of chemical application on the surface, and determining the best remediation strategies in response to the estimated solute. Generally, the solute flux field is described by associating the numerical solutions of the Richards Equation with the Advection-Dispersion Equation (ADE), which refers, respectively, to the movement of water and contaminants in unsaturated porous media.
The resolution of contaminant flow through classic numerical methods encounters several obstacles: it is known that the Richards Equation is highly nonlinear and requires substantial computational demand, which is further amplified when it comes to regional analysis. Moreover, for numerical models to perform at their maximum potential, they require a large amount of data and calibrations.
At the field scale, one of the intervening factors in solute movement is the natural variability of hydraulic properties, which results in different arrival times for solutes at a given control plane and can confer a greater longitudinal extension in the direction of the flow. Thus, probabilistic theories have begun to gain prominence, as they can deal with data uncertainties and field heterogeneities in a quantitative manner.
Thus, this research proposes the development of a probabilistic-regional model to simulate the transport of contaminants in heterogeneous porous media under unsaturated and transient conditions, thereby obtaining a three-dimensional mapping of the spatiotemporal dynamics of contaminated areas. With this, we aim to contribute to the New Geotechnics through transient and dynamic response maps (transient GIS), and by predicting the evolution of the solute plume in space and time, quantifying it, and determining its intensity. The prediction of the level of contamination supports risk analyses and also aids in defining strategies to mitigate its environmental impacts. These results would be obtained with lower computational efforts, facilitating the analysis of risk, which needs to be carried out periodically as it is a transient approach.
For model validation, field experiments and numerical simulations of contaminant transport will be used, and the results will be compared to verify the potential of the proposed model against those already used in the literature. In addition, complementarily, the model will be applied at the Construction Waste Receiving Unit (WRU) of the Federal District, known as the old Estrutural landfill, to gauge its applicability and compare it with existing studies in the region.

COMMITTEE MEMBERS:
Externo à Instituição - LÁZARO VALENTIN ZUQUETTE - USP
Presidente - 1805002 - ANDRE LUIS BRASIL CAVALCANTE
Externo ao Programa - 1804280 - ELEUDO ESTEVES DE ARAUJO SILVA JUNIOR - nullInterno - 404575 - NEWTON MOREIRA DE SOUZA