Riverbank protection removal to enhance habitat diversity through bar formation

Abstract

Over the past centuries natural river banks have been transformed into banks with artificial revetments or sheet piles to protect them from erosion. Important river features for flora and fauna have disappeared and the ecological quality of the river reduced dramatically. Recently, the importance of the ecological function of rivers has been getting more attention. One river restoration measure is the removal of man-made bank protections to increase habitat diversity and biodiversity of riparian areas and the river basin. The river morphology may change due to the freely eroding banks in the restored section. Reference projects show that the removal of bank protection along rivers may lead to the formation of bars (e.g. Schirmer et al., 2014). Bars increase morphological diversity, providing specific habitats for flora and fauna (Kurth and Schirmer, 2014). There is a lack of knowledge about the formation of bars related to the length and location of the removal of bank protection. The length of river bank protection removal is usually limited, due to human activities along the riversides. Therefore, a guideline is needed for the design of bank protection removal to enhance habitat diversity through bar formation to make this a feasible river restoration method.