What makes a first‐magnitude spring?: Global sensitivity analysis of a speleogenesis model to gain insight into karst network and spring genesis

Water Resources Research
By: , and 

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Abstract

Often, karstic conduit network geometry is unknown. This lack of knowledge represents a significant limitation when modeling flow and solute transport in karst systems. In this study, we apply Morris Method Global Sensitivity Analysis to a speleogenesis model to identify model input parameters, and combinations thereof, that most significantly influence evolution of karst conduit networks, development of first‐magnitude springs, and resulting flow and solute transport pulse responses. Based on an idealized model of the Silver Springshed in Central Florida USA, results showed that porous matrix hydraulic conductivity and parameters that govern connectivity of vertical and horizontal preferential flow paths (proto‐conduits) are the most influential parameters. In particular, a lower porous matrix conductivity is more likely to produce a first‐order magnitude spring. For the boundary conditions assumed in this application, conduits tend to develop in low topographic regions that drained nearby high regions. Morris ensemble realizations that generated first‐magnitude springs exhibit similar flow and solute transport pulse responses at the spring vent, despite differences in network configuration. However, distributed head fields are highly spatially variable, implying substantial spatial variability among solute flow paths and travel times from the land surface to the spring across realizations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title What makes a first‐magnitude spring?: Global sensitivity analysis of a speleogenesis model to gain insight into karst network and spring genesis
Series title Water Resources Research
DOI 10.1029/2017WR021950
Volume 54
Issue 10
Year Published 2018
Language English
Publisher AGU
Contributing office(s) California Water Science Center
Description 18 p.
First page 7417
Last page 7434