Catchments as simple dynamical systems: Catchment characterization, rainfall‐runoff modeling, and doing hydrology backward

Water fluxes in catchments are controlled by physical processes and material properties that are complex, heterogeneous, and poorly characterized by direct measurement. As a result, parsimonious theories of catchment hydrology remain elusive. Here I describe how one class of catchments (those in which discharge is determined by the volume of water in storage) can be characterized as simple first‐order nonlinear dynamical systems, and I show that the form of their governing equations can be inferred directly from measurements of streamflow fluctuations. I illustrate this approach using data from the headwaters of the Severn and Wye rivers at Plynlimon in mid‐Wales. This approach leads to quantitative estimates…

• NS
  National Science Foundation
• AC
  Adolph C. and Mary Sprague Miller Institute for Basic Research in Science, University of California Berkeley
• CF
  Centre for Ecology and Hydrology