Uncertainty in soil hydraulic parameters: A review of basics and methods

Abstract

The paper is a review article on the basics of uncertainty, necessity of its quantification and a comparative study of various methods of uncertainty estimation. The paper primarily focusses on uncertainty estimation of soil hydraulic parameters as of their pivotal importance in groundwater flow and transport simulations, soil moisture modelling techniques etc. The deterministic and probabilistic approaches of uncertainty quantification are studied and an understanding of uncertainty based on field scale measurements, empirical methods and pedotransfer functions is established. A comparative analysis of the basic methods of uncertainty analysis Monte Carlo, Bayesian, FORM/SORM and GLUE is done and the preferential use based on the importance is suggested. Bayesian approach was most suitable for evaluating parametric uncertainty, Monte Carlo was one of the most powerful tools but computationally expensive, FORM was applicable to both numerical and analytical solutions but didn’t guarantee a global convergence and GLUE was conceptually simple but gave only a statistical measure.