Thursday, February 9, 2017

Topography-Based Analysis of Hurricane Katrina Inundation of New Orleans

This article discussed the importance of geo-spatial data for the hurricane response and recovery teams after Hurricane Katrina in August 2005. During hurricanes in the past, the reaction times were delayed and the recovery times dragged on, thus providing no immediate help or relief. Using the new technological advancement of Light Detection and Ranging, or LiDAR, the recovery and response teams could act quicker with more efficiency by mapping rough estimates of inundation to track and monitor the post-disaster effects. This high resolution and elevation LiDAR data for Southeast Louisiana, specifically New Orleans (Figure 1), was integrated three months into the National Elevation Dataset (NED) before Hurricane Katrina and served useful during the recovery period when Hurricane Katrina hit. Today, the U.S. Geological Survey (USGS) organization has been constantly integrating LiDAR readings to include in the NED regarding topographic data for mapping and scientific applications of elevation.

Following the breaches of the levee’s in New Orleans, there was an influx in demand for mapping products that would in turn mark and measure the extent and magnitude of the flood waters. The maps created after the disaster provided sufficient information about the inundation and clean-up efforts (Figure 3). Unfortunately, the estimates were not enough to provide proper data as more accurate estimates of flood volume were needed to determine the amount of time needed to clean-up and remove the water from the city. (Figure 4) The extent of the flooding was based solely off hydrologic data from a gage in the nearby Lake Pontchartrain but this data too was inaccurate and subject to revision. Despite the drawbacks of the technology as it was not fully developed and processed in time for the ensuing storm, it still served as a pinnacle program for initial response efforts during the first days following the flooding and storm by demonstrating the true usefulness of detailed topographic data put alongside a real-time gage for inundation mapping in crisis situations where action was needed quickly.

In conclusion, the availability of high resolution and accuracy elevation data provided using LiDAR served as a crucial component in developing, maintaining, and mastering topography-based products and research to provide inundation estimates following Hurricane Katrina. In the future following Hurricane Katrina up until now, LiDAR provided a way to not only map ground-based water level information, but also note the exact areas of flood plains and how they interacted with the urban landscape. It also was useful in determining and planning the reconstruction of the New Orleans infrastructure by allowing the Government and building companies with a tool to analyze and decide on the best construction techniques to mitigate negative impacts caused by future storms.

Gesch, D. (2005). Topography-Based Analysis of Hurricane Katrina Inundation of New Orleans. Science and the Storms: The USGS Response to the Hurricanes of 2005, 53-56. Retrieved February 9, 2017.

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