GIS derived synthetic rating curves and HAND model to support on-the-fly flood mapping

Abstract A timely and cost-effective method of creating inundation maps could assist first responders in allocating resources personnel the event a flood or preparation future disaster. The Height Above Nearest Drainage (HAND) model be implemented into an on-the-fly mapping application for Canada-wide service. HAND requires water level (m) data inputs while many sources hydrological Canada only provide discharge (m 3 /sec) data. Synthetic rating curves (SRCs), created using river geometry/characteristics Manning’s formula, utilized to approximate given input. challenge with SRCs includes representing how multiple different land covers will slow impact flow due texture bulky features (i.e., smooth asphalt versus rocky channel); this relates roughness coefficient ( n ). In our study, two methods values were experimented (a weighted minimum-median method) compared fixed method. custom ArcGIS tool, Canadian Estimator Ratings Curves Discharge (CERC-HAND-D), was developed create all three methods. Control sourced from gauge stations across form curves. Results indicate that areas medium medium–high gradients (S > 0.002 m/m) reaches under 5 km, CERC-HAND-D tool creates more accurate (NRMSE = 3.7–8.8%, Percent Bias ?7.8%—9.4%), being preferred