THE USE OF A FLOOD DISRUPTION SCALE TO COMMUNICATE HIGH RESOLUTION FLOOD HAZARD USING PARCEL SCALE TIDAL AND RAINFALL RUNOFF MODELS FOR PLANNING IN CHARLESTON, SOUTH CAROLINA

Charleston, South Carolina is already experiencing the impact of climate change on a regular basis. Tidal, storm surge and rainfall event-based flooding make it one of America’s most vulnerable coastal cities. With the low elevation, a vast coastline, and estuary shorelines, flooding is the most important hazard to the residents of the region. However, rising water levels have already begun to impact the region, influencing infrastructure, property, and dollars. The increasing frequency of flooding and damage from these events has highlighted the need for better mapping and communication of the area’s most susceptible climate-induced hazards.

A one-meter resolution digital elevation model created from LiDAR as well as one-meter resolution impervious cover created using LiDAR-Multispectral Fusion techniques have been used to develop high resolution- parcel scale hydrologic models. The modeling created small, connected “urban watersheds” which have been to highlight the area’s risk to storm and tidal events. A regional Flood Disruption Scale is being used with the modeled data to better communicate risk to the citizens and policy-makers in the region. The model presented here reflects a shift in the way data has been used in the past from reactive-based to proactive data driven decision products for response and mitigation. These products translate hazards to stakeholders in a form they can relate to – the streets and buildings of their community – the data has become useful for those that wish to incorporate them into their regional, as well as, personal adaptation practices.