“InfraRivChange”: A webbased application to monitor river migration at sites of critical bridge infrastructure in the Philippines

Dr Richard J. Boothroyd, Dr Richard D. Williams
University of Glasgow, United Kingdom

Prof Trevor B. Hoey Brunel
University London, United Kingdom

Abstract: Shifting rivers represent a geomorphic hazard at sites of critical bridge infrastructure, particularly in rivers where migration rates are high. Conventional attempts to map and measure shifts in the position of rivers usually requires manual digitization of satellite imagery using Geographic Information Systems (GIS); this type of analysis is time consuming and so can only be applied to a handful of bridge sites, using a small number of satellite images. As part of the CDRI Fellowship, we leveraged the cloud computing platform Google Earth Engine (GEE) to upscale hazard monitoring assessments at large bridges in the Philippines using Earth observation (EO) data. We designed a user-friendly web-application that enables stakeholders to monitor the relative risk of river migration by analysing thousands of satellite images. The “InfraRivChange” web-application uses freely available satellite imagery from Landsat (30 m spatial resolution) and Sentinel (10 m spatial resolution). We demonstrate the workflow and show results from the Gamu Bridge on River Cagayan (Landsat imagery), Itawes Bridge on River Chico (Landsat imagery) and Don Mariano Marcos Bridge on River Lagben (Sentinel imagery). Outputs can be used by key decision-makers (e.g., the Department of Public Works and Highways) to assess the relative risk of river migration at sites of critical bridge infrastructure. We recommend using our “InfraRivChange” web-application as a lowcost remote sensing approach to monitor shifting rivers at sites of critical bridge infrastructure. We envision that the web-application can be applied to other critical infrastructure adjacent to rivers (e.g. road, rail and pipelines) and extended elsewhere to other dynamic riverine settings.