Research

We investigate how materials are transported across and within the hyporheic zone, a region where stream water and groundwater mixes. In energetic streams with coarse-grained beds (e.g., gravels), turbulent eddies rapidly pulse materials into the streambed, but this process is not well characterized in transport models. We conduct physical and numerical experiments to develop improved models of mass transport in streams and rivers.

Relevant publications: Lian et al, 2021; Roche et al., 2019; Sherman et al, 2019; Lian et al, 2019; Roche et al, 2018

Water’s movement controls the habitability of any freshwater environment by delivering  nutrients, redistributing contaminants, and imparting shear stresses on organisms. In turn, organisms can both directly and indirectly control the movement of mass in freshwater systems. We investigate feedbacks between hydrology and biological activity, in an effort to understand how they evolve in time and how they are sensitive to external environmental perturbations.

Relevant publications: Aquino et al, 2017; Roche et al, 2016

There is growing evidence that changing precipitation patterns are not only impacting freshwater ecosystems, but also human decisions. We are investigating the mechanistic links between changing hydrology and myriad processes at the scale of river basins. This work is primarily focused on developing analytical models based on theory of stochastic processes, as well as using field data to understand the link between climate and stream drying.

Relevant publications: Müller et al, 2021; Roche et al., 2020