Application of Feedback Analysis in Hydrological Modeling

Elizabeth Kahler1,2, Jesse Dickinson2, and T.P.A. Ferré1

1Department of Hydrology and Atmospheric Sciences

The University of Arizona, Tucson, AZ

2U.S. Geological Survey, Tucson, Arizona

Feedback analysis has been a standard element of the design of electrical systems for almost one hundred years and has been an important tool in climate change studies for decades. This study is motivated by the lack of feedback analysis in hydrologic science. We propose that feedback analysis can be applied to hydrologic models to identify the most and least stable parts of a hydrologic system. In this study, we focus on modeling groundwater flow systems and quantify a feedback strength, which is a relative index of the importance of a feedback mechanism in regulating the system response to an external stress. Resource managers may use the feedback strength as a tool to identify and protect the least stable areas, or identify the feedback mechanisms in stable areas that could be developed to enhance stability in more vulnerable areas. This project builds on feedback analysis of simple electronic circuits, borrows from advances in the atmospheric sciences, and develops a new feedback analysis for groundwater systems and models.