An Examination of Costs and Benefits for Capturing Meaningful Hydro-Geomorphic Criteria for Aquatic Biota in Rivers

Alterations to hydrology and habitat from climate-change effects are expected to fundamentally impact aquatic biota in riverine systems. Fluvial hydrogeomorphic variables, such as channel dimensions, sediment size, and topography, are important when establishing the habitat requirements of riverine biota, but measurements can be time consuming and expensive when high spatiotemporal resolutions are needed. We examine tradeoffs between costs and benefits when measuring in-stream variables, remotely sensed landscape data, and hydrodynamic models to infer habitat availability for riverine biota using examples from Missouri. Transect-based variables can be efficient to collect, but are limited in their capacity for broad-scale inferences across time and space. Remotely sensed layers are broadly distributed across space, but require long processing times and may represent only a single point in time. Hydrodynamic models are time-consuming to build and limited in their availability, but provide highly-detailed representations of the riverine landscape and aquatic habitats. Understanding these tradeoffs improves the probability of inferring meaningful habitat-biota relationships at relevant spatiotemporal scales.