CoreLogic Storm Surge Report 2013 released

CoreLogic senior hazard scientist, Dr. Thomas Jeffery, the primary author of this year’s CoreLogic Storm Surge Report, answered some questions about their research.

GISCafe Voice: Has the number of homes at risk of hurricane storm-surge damage increased since your last storm surge report was issued?

Dr. Thomas Jeffery: The number of homes at risk in the 2013 report did change from last year. In most locations, the number of homes with the potential for surge risk has increased  There are two reasons for the change.  Each year there is new residential construction that increases the number of homes across thecountry.  New residential development has occurred near the Atlantic and Gulf coasts since 2011/2012.  This new construction will add slightly to the
number of homes potentially at risk.  The larger change in the number of homes listed in the report is due to the manner in which we are able to identify residential properties.  In the past we have used the most comprehensive data set available, but for the report this year we were able to get more complete geographic coverage of residential properties through an improved analysis method of locating homes along the coast.  Therefore the change in the number of homes in our report has increased in most locations due to an improved system of locating and tabulating properties that occur within a potential surge risk zone.  Although this granular approach to assessing the surge hazard at the property level is the most arduous, it is also the only way to accurately evaluate potential surge damage, as opposed to only evaluating the risk by coastal county or state.

GISCafe Voice:  Are you also taking into account changes in the coastlines in each report?

Dr. Thomas Jeffery: We do account for changes in the coastal areas.  The surge risk data that is used in our annual report incorporates the current coastal boundary data which we update annually.

 GISCafe Voice: What mapping sources besides FEMA are you using to gather information?

Dr. Thomas Jeffery: Most of our mapping is based on CoreLogic analysis – the FEMA data are brought in and used as a comparison with the surge risk we create.  For the mapping, I don’t believe we have any other sources – the coastline data, housing data and surge analysis is all CoreLogic…though we do also use NOAA and USGS data as input data for our analysis.

GISCafe Voice: Why is it that this is the first time CoreLogic’s report addresses the potential impact of a climate-related rise in sea level on coastal storm-surge risk in a select number of metro areas?

Dr. Thomas Jeffery: Sea-level rise is part of an on-going discussion of climate change within the scientific community.  Our primary research is specifically focused on the evaluation of current hazards such as hurricane driven storm surge and we do not research climate change.  As such, our data are intended to reflect the current risk, which is of most value to our clients and to the public, at present.  However, any discussion of natural hazard risk tends to include questions regarding future events and changes in patterns or severity.  Without analyzing the actual process of climate change, we decided to investigate potential impacts of sea-level rise in order to gain a better understanding of potential for storm surge risk damage in the future.  This was driven by our scientific curiosity and a desire to utilize our data in an effort to better understand what sea-level rise may mean to the future residents of coastal areas.  The reason for including it at this time is more due to opportunity than anything else.  We were able to devote the time and resources to it this year and since it appears to be of concern to an increasing number of people, we felt it was time to explore this topic.

GISCafe Voice: How do you foresee the future reports? Do you think that actions such as the actions taken in New Orleans to build protective levees will lessen the risk in other extreme risk areas? Will some areas remain extreme risk in
spite of manmade actions to deter disasters?

Dr. Thomas Jeffery: Future reports will continue to analyze and tabulate the potential risk from storm surge with the intent of providing a granular hazard evaluation for residents of the Gulf and Atlantic coasts.  We intend to continue with our property level assessment of the hazard with the intent of raising awareness of the geography of this risk.

The efforts undertaken in the New Orleans area have proven to be beneficial in reducing the risk to the residents.  Hurricane Katrina identified some areas that needed enhancement and those modifications have been implemented.
Last year, Hurricane Isaac, a Category 1 storm, tested some of these mitigation improvements and they were successful at preventing flooding in the areas they protect.  I think that the successful application of mitigation efforts such as those in New Orleans will be viewed as options for other communities, but not all coastal areas will be able to implement similar devices.  Since not all coastal areas have the same geography as New Orleans, it may not be feasible to develop similar protection systems in areas where the coastline and development pattern is vastly different.  In addition, a primary consideration with any type of mitigation is the cost. The cost of implementing levees can easily run into the billions of dollars,
and would have to be evaluated against the reduction of damage that the system would provide.

We have been able to engineer our way around some of the risk that comes from natural hazards, but I doubt that we will ever see the day where risk to property is eliminated by our mitigation efforts.  The whole idea of
mitigation is to reduce the risk from the most common or frequent events, thereby reducing the property damage or loss for most of the people most of the time.  But to render an area entirely free of risk is an unlikely
scenario.

Tags: CoreLogic, geospatial, GIS, hurricanes, mapping, NOAA, storm surge, Storm Surge Report, USGS

Categories: CoreLogic, storm surge

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