Fluvial landscapes of Costa Rica: an overview of dynamic rivers

Abstract

Costa Rica, a small tropical country with an area of 51,179 km2, has an extensive network of diverse streams controlled by varied environmental and geological conditions. Rugged terrain, active volcanism, and tectonic activity, along with intense precipitation, result in a dynamic drainage system characterized by a wide array of erosive and depositional fluvial landforms. In this chapter, a generalized characterization of Costa Rica's riverscapes is provided, with a focus on channel morphologies and fluvial dynamics within selected reaches across the country. Using a range of remote sensing techniques, including Unmanned Aerial Vehicles (UAVs), hydraulic modeling, and detailed field observations, representative river sections situated within distinct geological contexts are described. The findings illustrate how rivers flow in confined steep volcanic-mountain settings, on alluvial fans, within low-gradient unconfined dynamic reaches, and in urban environments. Moreover, we discuss the intrinsic connection between channel morphology, surface processes, and associated hazards, as most of the disasters occurring in Costa Rica are tied to fluvial environments.