Surface-water connectivity of geomorphic habitats across lowland river floodplains

Keywords: river, connectivity, hydrology, geomorphology, lowland, floodplain
Abstract Type: Paper Abstract

Abstract

Surface‐water connectivity, also called lateral hydrological connectivity, between a river and its floodplain plays a major role in water, sediment, nutrient, biotic, and temperature exchanges within lowland river landscapes. The surface-water connections between the patches characterizing the landscape create a dynamic network, which varies spatially and temporally in size, configuration, and function reflecting the magnitude, frequency, and duration of flows. In this study, we examine the surface-water connections between the Mission River, a coastal lowland river in Texas, and its floodplain across the historical range of flows. We accomplish this by simulating inundation maps via two-dimensional hydrodynamical modeling. Our findings show that surface‐water connectivity represents the characteristics of roughly scale‐free networks. Geomorphic patches that pertain to the active, semiactive, and abandoned channels act as highly connected hubs that maintain network‐level connectivity. River landscapes are self‐organizing toward scale‐free surface‐water connections among patches that optimizes energy and matter exchange. This knowledge is important in identifying reference landscapes that can be used to validate landscape evolution models and develop strategic goals for lowland river restoration and management.