THE EFFECT OF URBANIZATION ON THE MORPHOLOGICAL EVOLUTION OF SCHNEIDER CREEK IN SOUTHWESTERN ONTARIO

Changes in land-use and urbanization can result in considerable adjustments to the morphology of rivers and streams. It is important to understand how rivers respond to such changes in order to manage stormwater runoff and protect both ecosystem health and water resources. The goal of this research is to analyze the morphological evolution of a stream network following a period of increasing urbanization. Schneider Creek situated in southwestern Ontario, Canada, is used as a case study for this research. This creek has a drainage area of 74 km² and is situated within the larger Grand River watershed. Over the past 80 years this region has been transformed from being primarily agricultural in 1940 (78% agricultural and 9% urban) to largely urbanized in present day (7% agricultural and 74% urban). As a result of this, the morphology of Schneider Creek and its tributaries has adjusted considerably due to changes in discharge, natural meandering of the stream, and river engineering practice. For this research, aerial photographs from the 1940s, 1950s, 1960s and present day (2016) were analyzed in geographic information system (GIS) software. Temporal adjustments in stream width, channel length and sinuosity of the creek and its tributaries were quantified. Results indicated that the morphology of Schneider Creek, which was once a river dominated by natural meandering patterns, is now largely controlled by river engineering and stream stabilization (e.g., channelization) measures. Based on these results, the effect of river engineering and stream stabilization measures on upstream and downstream morphological changes is assessed and a relationship between the degree of movement and level of stream stabilization measure (i.e., degree of stream bank immobilization) is sought. Future work will investigate the role of changes in hydrological patterns (e.g., increase in precipitation during this period) on the morphological evolution of Schneider Creek.