1.2 Approach and Scope
Here, we investigate how spatio-temporal changes in precipitation may
influence erosion and topography of mountain landscapes using the stream
power model (SPM). First, we show how simple spatial gradients in
rainfall, resembling typical orographic precipitation patterns (i.e.,
increasing or decreasing downstream; herein referred to as bottom-heavy,
and top-heavy, respectively), influence river profile form at steady
state in one dimension. Next, we use a quasi-two-dimensional numerical
model to simulate the response of a transverse river network to a change
in rainfall pattern, which we compare to better-understood spatially
uniform changes in rainfall. Finally, we discuss some implications for
studies set in mountain landscapes. A comprehensive analysis of the
co-evolution of orographic rainfall patterns and topography is beyond
the scope of this paper. Instead, we focus on characterizing the
controls on landscape response to imposed changes in rainfall patterns,
highlighting where expectations differ from uniform changes in rainfall,
and implications of those differences.