PNNL

Abstract

The riparian corridor is a key component of the critical zone and an essential component of watershed systems. According to Merriam-Webster Dictionary, the word riparian is derived from the Latin word riparius, meaning \existing alongside a river." Riparian corridors typically extend from a few meters to hundreds of meters adjacent to a river and are marked by rich biodiversity, vegetation, and intense biogeochemical activity. They act as integrators of watershed processes and constitute the primary pathways for the subsurface geochemical exports from the watershed. Although riparian corridors comprise only 2% to 10% of a watershed's area, as much as 90% to 98% of biogeochemical processing in watersheds occurs in this region, thereby affecting the subsurface geochemical exports and downstream river water quality. Indeed, the riparian corridor is a good example of the Pareto principle (e.g., Dwivedi et al., 2018a; McClain et al., 2003; Bernhardt et al., 2017). This outsized contribution occurs at the interface between aquatic (river) and terrestrial (land) environments, where interactions between hydrologic and biogeochemical processes are intensified. Variations in the river corridor over time can thus also have outsize impacts. Therefore, it is important to understand the hydrological and biogeochemical linkages in riparian corridors to determine water availability and quality for sustainable management.