Functional Assessment with the Riparian Ecological Function Index (REFI)
Samantha Wiest
USACE ERDC
Environmental Laboratory (EL)
US Army Engineer Research and Development Center (ERDC)
Vicksburg, MS
Authors:
-- Garret Menichino, Environmental Laboratory (EL), U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS
-- Kyle McKay, Environmental Laboratory (EL), U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS
-- Samantha Wiest, Environmental Laboratory (EL), U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS
Riparian zones are important transitional areas between upland and stream ecosystems that improve water quality, provide ecological habitat and corridors, maintain hydrologic processes, and provide other ecosystem goods and services. Some regional tools have been developed to assess impacts and benefits of riparian zones, but no nationwide models or modeling frameworks address riparian outcomes. Furthermore, existing tools are generally a subcomponent of stream assessments with an emphasis on riparian effects on instream functions. Practitioners need nationally applicable tools for consistently assessing impacts and benefits of riparian management actions. We developed a framework for filling this gap called the Riparian Ecological Function Index (REFI), which is a semi-quantitative, rapid assessment technique for riparian ecosystems across the continental United States. REFI is structured around three riparian outcomes: (1) effects on instream outcomes (2) ecological connectivity, and (3) unique and important habitats. In this presentation, we describe the REFI process and demonstrate application of REFI in an urban stream restoration project in Atlanta, Georgia. The case study applies REFI to multiple reaches in a 30 square mile watershed. Results indicate a range of riparian conditions affected by development within the watershed, from heavy impairment to well-functioning. REFI is additionally used to forecast riparian conditions from different management and restoration actions and inform planning and design decisions.
About Samantha Wiest
Samantha Wiest is a research environmental engineer with the US Army Engineer Research and Development Center (ERDC). She recently obtained her Engineer Intern (EI) license, graduated from Oregon State University with a BS in Ecological Engineering, and is hoping to earn a Master’s degree in a related field. In her years at ERDC, she has worked on projects related to developing a riparian model for impact and benefit assessment, storm water management, and developing hydraulic models for habitat research.