Introduction to Logjam Research

Introduction to Logjam Research

My name is Alexander Kalna, or Xander for short. During my time at SIUE, I am conducting research on logjam (what are logjams?) interactions in streams. This research falls into the fluvial geomorphology field (learn about fluvial geomorphology here!) as it studies the impacts of large wood on the water and sediment transport and shape of streams. This research is important because scholars have not intensely researched logjams in the Midwest like they have in the Pacific Northwest, Rocky Mountains, or the Appalachians and Eastern Coast. Logjam research is especially important in the Midwest because this region contains the US’s largest watershed, the Mississippi Watershed, which covers all or part of 31 states and parts of Canada.

My research includes reading lots of scientific papers, using geospatial information systems (learn about GIS here!) programs like Google Earth, and taking several measurements and observations from a local creek, Silver Creek. In Silver Creek, I find logjams and with the help of a few others, we gather data from the logjam such as the width and length of pieces, the complexity of the jam, and the effect the logjam is having on nearby creeks. We use a high quality GPS to record the exact location of parts of the creek. Having these locations, we can see how the stream channel is shaped at that cross section compared to areas without logjams. Logjams usually cause sand or gravel to gather up or downstream of the jam, the jam can create a sand or gravel bar like you can see in the photos.

Research on logjams in this region helps organizations performing stream and river restorations make more informed decisions. It is important to know how much wood, what sizes of wood, causes of the logjam, and what the logjams change in the stream so that restorations can be worthwhile and effective. Logjams are important in streams as they cause changes in the local environment, creating a variety of habitats such as pools and riffles as well as providing shelter and habitat for microorganisms and aquatic animals like snakes, turtles, and fishes.