Project: T122700 #0233
 
Published April, 2014
Development of Standardized Inundation Maps Produced using Geographic Information Systems (GIS)

CEATI’s Dam Safety Interest Group (DSIG) outlined a variety of needs in the field of Emergency Management.  One area of particular interest was the technological advances in developing inundation maps for dam breach and other extreme hydrologic events.   The presentation and application of the GIS based inundation maps vary considerably, and the purpose of this study is to develop a standardized practice for the dam owners.  This will benefit the downstream response agencies that must interpret the inundation data and maps under emergency situations.

Over the last two decades, there has been significant development in both dam breach hydrodynamic modeling and use of Geographic Information Systems (GIS) to visually present and understand the flooding impacts to downstream communities.

This study addresses the key components of this process that relate to both the application of GIS to visualization, and the application of the inundation mapping for risk assessments and emergency planning.  The key deliverable for this study is guidelines for the standardization of GIS based inundation maps. Other related topics addressed include a discussion on warning times and the use of low tech solutions to develop simple and approximate inundation maps.

The study commenced with an interview ofthe sponsors in order to understand their current practice, the needs of their downstream communities and their future plans in using GIS based inundation maps.  This phase included an examination of the existing standards and guidelines in Canada and the United States with respect to the application of GIS to inundation mapping.  A factual report, summarizing these findings, was prepared and distributed to the sponsors.

On June 20th, 2013, dam owners, regulators and emergency management agencies participated in a one-day workshop in Toronto, Canada, to review these findings and finalize guidelines on the GIS application to inundation mapping.

This final report incorporates the results of the Toronto workshop, follow-up discussions with the sponsors and recommended guidelines for GIS based inundation maps.  These guidelines cover topics such as data collection, creating the digital elevation model, hydraulic modeling and presentation and application of the inundation map.

Keywords:

Dam Breach, Inundation Maps, Geographic Information Systems, Emergency Action Plan, Flood Response Planning