Influence of Riparian and Watershed Alterations on Sandbars in a Great Plains River

Abstract

Anthropogenic alterations have caused sandbar habitats in rivers and the biota dependent on them to decline. Restoring large river sandbars may be needed as these habitats are important components of river ecosystems and provide essential habitat to terrestrial and aquatic organisms. We quantified factors within the riparian zone of the Kansas River, USA, and within its tributaries that influenced sandbar size and density using aerial photographs and land use/land cover (LULC) data. We developed, a priori, 16 linear regression models focused on LULC at the local, adjacent upstream river bend, and the segment (18-44 km upstream) scales and used an information theoretic approach to determine what alterations best predicted the size and density of sandbars. Variation in sandbar density was best explained by the LULC within contributing tributaries at the segment scale, which indicated reduced sandbar density with increased forest cover within tributary watersheds. Similarly, LULC within contributing tributary watersheds at the segment scale best explained variation in sandbar size. These models indicated that sandbar size increased with agriculture and forest and decreased with urban cover within tributary watersheds. Our findings suggest that sediment supply and delivery from upstream tributary watersheds may be influential on sandbars within the Kansas River and that preserving natural grassland and reducing woody encroachment within tributary watersheds in Great Plains rivers may help improve sediment delivery to help restore natural river function.

Channel morphology and flow structure of an abandoned channel under varying stages

“…Under such conditions, deposition occurs along the length of the abandoned channel rather than focused at the channel entrance [ Constantine et al ., , 2010b; Sutton et al ., ]. The bed material of the Kansas and Big Blue rivers, like other large rivers in the region [ Costigan et al ., ], is fine‐grained [ Fischer et al ., , ] and the bed of the abandoned channel likely aggraded quickly when it was transitioning from being the main course of the Kansas River [ Constantine et al ., ]. Sections in the middle of the abandoned channel were unable to be surveyed due to shallow depths, which are likely the location in the channel where bed load transported into the channel deposited.…”

“…Gallery forests form the riparian zone of the Kansas and Big Blue rivers [ Veach et al ., ]. The Kansas and Big Blue rivers are both large, fine sand‐bed rivers with meandering planforms [ Fischer et al ., , ]. The bed of the abandoned channel was at a higher vertical elevation than the bed of the Big Blue and Kansas rivers (e.g., the bed of the abandoned channel is perched).…”

Response of Terrestrial Insect Community to the Vegetation Invasion at a Sand-Bed Stream

“…더불어 인간 간섭에 따른 물 흐름 과 유사 이송의 변화, 수질 오염 등에 의하여 사주 형성 이 제한되고 식생이 사주에 번성하게 된다 (Graf 2006, Woo andPark 2016). 사주 형성이 저해되고 기존의 사 주에 식생이 고착됨에 따라서 이곳에 정착한 생물상과 군집구조에 변화가 뒤따르게 된다 (Smith 2011, Stucker et al 2012, Fischer et al 2015.…”

Land Use Change Trajectories for Wetland Management (Mogi-Guaçu Floodplan River, Southern Brazil)

“…Natural and anthropogenic factors, as well as their synergistic combinations are mainly responsible for changes in wetland functions and structures [4] [5] [6] [7].…”

“…changes on the river course, in sandbar extent formation, and oxbow lake genesis and extinction) [11], and have brought about a decline in the biota dependent on terrestrial and an aquatic transition wetland habitats (Fischer et al 2015). Detecting land use changes is an important tool to identify geographical dynamics and their association with anthropogenic activities.…”