Summary of "Hurricane Ike: Revisited"
Date: September 14, 2009
On September 13, 2008, the greater Houston-Galveston area was waking up to no lights, no air conditioning, flooded streets and little running water. The area was facing the aftermath of Hurricane Ike that blew into the area that night, causing more than $27 Billion dollars in damages. One year after Ike, on September 14, 2009, a Rice University team of experts at the Severe Storm Prediction, Education and Evacuation from Disasters (SSPEED) Center hosted a day-long event that revisited the storm to determine what has been learned from that devastating occurrence, and what has been put in place for preparation of future severe storms.
Over 150 participants from local emergency management offices, county and city departments, academia, independent consulting and local engineering firms attended “Hurricane Ike: Revisited”. Dr. Philip Bedient, the SSPEED Center Director, kicked off the conference at 9 a.m. followed by KHOU Channel 11 Chief Meteorologist Gene Norman, who addressed meteorology of the storm before, during and after Ike made landfall on the Texas Gulf Coast. Dr. Gordon Wells with the Center for Space Research at the University of Texas discussed the characteristics of the Ike storm surge and was followed by a discussion of the metrological aspects of Ike by Mr. Jeff Lindner of Harris County Flood Control District. Dr. Clint Dawson of The University of Texas continued with the storm surge modeling using ADCIRC models and the session was concluded by Dr. Bedient, who discussed the linkage of inland flooding and storm surge of Galveston Bay.
The principal points of the morning session focused on storm surge and its relation to both storm event modeling and perceived risk of a given storm. In the case of Hurricane Ike, ranked as a category 2 storm according to the Sapphire-Simpson scale, the outcome resulted in a powerful storm surge and intense flooding along highly populated areas. The ADCIRC and SLOSH models presented in this discussion underscored the complexity associated with hurricane storm surge and the need to better understand its components. Among these components is the unique bathymetry of the Texas Gulf Coast that, in the case of Hurricane Ike, resulted in enhanced wave propagation along coastal areas, especially evident on the Bolivar Peninsula. Also unique to the area is the variation in wind fetch distances throughout Galveston Bay, which serve to further vary storm surge depths along the coast. Such advanced modeling uncovers the lack of ability of the Sapphire-Simpson scale to fully describe to people the potential destructive impacts of a given hurricane, and further supports the need for a more cogent land-use planning model unique to the Texas Gulf Coast.
The afternoon began with a talk from Dr. Sam Brody of Texas A&M University concerning land use and was followed by Environmental Defense Fund’s Mary Kelly who took the lessons learned from the Louisiana coast and applied them to the Texas Gulf Coast. Community planning for flood prone coastal areas was addressed by Kevin Shanley, President of the SWA Group in Houston, and Dr. Hanadi Rifai of the University of Houston discussed the environmental risks and consequences of Ike with reference to the Houston Ship Channel.
Traffic management during both Hurricanes Ike and Rita was discussed by both Dr. Carol Lewis of Texas Southern University and Mr. Alan Clark of the Houston-Galveston Area Council. Mr. Bill Wheeler, Deputy Emergency Manager of the Harris County Office of Emergency Management discussed Harris County’s successful response following Ike, and Mr. Charlie Penland of Walter P. Moore continued with more of the lessons learned from Ike and TS Allison, which hit Houston in 2001. Discussing Galveston’s response to Ike and the plans of recovery that have since been put into place was illustrated by Ms. Betty Massey of the Mary Moody Northern Foundation and the Galveston Community Recovery Committee.
The main idea of the afternoon session dealt with hurricanes and community preparedness where the essential and primary goal of achieving an acceptable level of preparedness became an accurate risk assessment. This may involve redefining the current floodplain maps to include a wider swath of surge area, as well as assessing the impact of previous storms.
Risk assessment was followed by mitigation and, as evinced by Dr. Brody, structural mitigation is only one part of a complete strategy and may indeed serve to exacerbate certain impacts. Non-structural mitigation strategies such as land-use planning and building codes must also be employed, and in doing so may greatly reduce the impact to community members.
Although advanced planning may greatly reduce the damage potential of a hurricane, damage will inevitably occur. As such, it is important to understand what risks a community has taken as a result of land-use planning and settlement strategies. Relative to the Houston area, a large population and a condensed center of employment have been built in the direct path of future storms. In addition to this urbanization, chemical and petrochemical production and storage facilities have become part of the area, plus landfill and waste disposal sites, not to mention an extensive sewer and water distribution network. Given such development, certain risks must be accepted and planned for. Transportation, sewage, water, electricity, and environmental impacts represent community factors in need of contingency plans in preparation of future storms.
The evening session involved presentations from Mr. Gene Hafale of the National Weather Service (NWS), Mr. Jim Blackburn, Co-Investigator of the SSPEED Center and Professor of the Practice at Rice University, Dr. Robert Stein, Professor at Rice University, and Harris County Judge, the Hon. Ed Emmett who spoke of his role during and after the storm for the citizens of Harris County, and indicated the overall success of the county’s response to Ike. This final session dealt with hurricane activity and human behavior; specifically what past storms have taught us and steps we can take to reduce potential future damage. Land-use planning comprised a significant portion of these talks with Mr. Blackburn presenting the idea of re-defining coastal settlement. Two key points of his talk was making Bolivar Peninsula a national seashore area to function as a naturally protective barrier island and introducing a possible managed retreat away from the most vulnerable parts of the coast.
Dr. Stein presented an assessment of the decisions that an evacuee may make just before the evacuation. A number of factors play a role in the decisions of the evacuee, including actions taken for past storms, neighbors’ actions, and perceived risk. It also became apparent that underestimating a storm’s damage potential may result in insufficient action. Overestimating the risks involved may cause problems for evacuees that do face significant risks by crowding evacuation routes. Stein’s study showed that past experience plays a large role in evacuation decisions, with the percentage of people correctly staying as opposed to evacuating nearly doubling from Hurricane Rita to Hurricane Ike. However, given the large number of people that faced power outages associated with Hurricane Ike, the percentage of people that stayed may be expected to change for the next storm.
To reiterate, any strategy for storm mitigation begins with understanding and communicating the risks over a given area for a complete range of storm scenarios. Following this risk assessment, actions must first be taken to avoid the areas of highest risk where possible, and to allow for mitigation in those areas where certain risks may not be avoidable. Cost must be balanced with need and ideal solutions must be garnered with practical availability to result in actions with maximum utility.