Analyzing Geomorphologic and Hydrologic Controls of Long-term River Channel Migration

Rivers undergo migration owing to erosion and sedimentation along its banks. While these processes are gradual, flood events can accelerate river migration which can pose a significant risk to human lives and infrastructure. It is, therefore, crucial to delineate river reaches that are prone to channel migration and quantify the extent of migration of such rivers. However, detailed information regarding river migration across entire river networks are seldom available. This study aims to quantify long-term river migration across large watersheds and analyze the factors controlling river migration. The proposed methodology implements particle image velocimetry on Landsat images for the past three decades to quantify the median migration of each reach in a river network. The methodology is demonstrated for the Wabash River Basin in Indiana. Additionally, the correlation between migration and reach sinuosity, drainage area, geology, streamflow, flood frequency, and degree of urbanization is also analyzed. Results show that drainage area and flood frequency have a high correlation with river migration. An understanding of the long-term patterns of river channel migration will enable decision and policy makers to better plan for resilient infrastructure.