'InfraRivChange': a web application to monitor river migration at sites of critical bridge infrastructure in the Philippines

Shifting rivers, particularly with high migration rates, represent a geomorphic hazard at sites of critical bridge infrastructure. Conventional attempts to map and measure shifts in the position of river channels usually requires the manual digitization of riverbanks from satellite imagery using Geographic Information Systems (GIS) - a time-consuming process only feasible at a limited number of bridge sites using a small selection of satellite images. As part of the CDRI Fellowship, the authors leveraged the cloud computing platform Google Earth Engine (GEE) to substantially upscale analyses using Earth observation (EO) data. Focusing on the Philippines, they designed a user-friendly web application for technical and non-technical users to monitor the relative risk of river migration at sites of critical bridge infrastructure by analysing thousands of satellite images. `InfraRivChange' uses openly accessible satellite imagery from Landsat (30mspatial resolution) and Sentinel (10 m spatial resolution) to quantify river channel changes at bridge sites. The study demonstrates the web application at test sites and suggests use-cases relevant to disaster resilient infrastructure. As a low-cost approach for monitoring shifting large rivers in the vicinity of infrastructure, InfraRivChange can be incorporated into bridge monitoring systems (e.g., as a component of bridge stability assessments) and inform the design and placement of future infrastructure. They envision that InfraRivChange can be applied to additional forms transport infrastructure adjacent to rivers (e.g., road and rail) and extended to other dynamic riverine settings.