Hurricane Katrina and GIS

Topography-based Analysis of Hurricane Katrina

Inundation of New Orleans

This article (Gesch, 2007) discusses Hurricane Katrina and the methods, such as topography, that were used to determine the elevation and flooding of the city of New Orleans, and how those methods were used in the aid of people in the city after the catastrophic hurricane of 2005. To fully understand this article, however, background research on New Orleans and hurricanes needs to be discussed to comprehend the devastation of the city and the reasons behind it.

Inundation, or flooding, is a major problem for cities located near large bodies of water, as well as places that are of low elevation. When a hurricane strikes, the storm surge is thrust in front of the storm. This is due to the ocean water being pushed towards the shore of a coastline by the force of the winds from the hurricane moving cyclonically around the eye of the storm.

Some factors can affect the intensity of a storm surge, such as the slope of the ocean floor leading up to land. A shallow slope usually leads to a more intense storm surge versus the slope of a steep shelf. This can be shown in the impact of the same intensity hurricane in two diverse areas. The shallow slope of the Louisiana coastline and the steep slope of the Florida coast would make a hurricane of the same strength produce a potentially 20 foot storm surge in Louisiana, and only a 8 foot storm surge in Florida.

Storm surge, according to NOAA (the National Oceanic and Atmospheric Administration), is often the deadliest component of a hurricane, and usually causes the most damage to property as well. This can inundate the coastline, causing major flooding events in areas that might not even flood normally. Hurricane Katrina produced the highest storm surge ever recorded on the U.S. coastlines, a catastrophic 27.8 feet (NOAA.gov). This completely devastated the city before the full brunt of the storm had even reached landfall, producing more rain to even further flood New Orleans. 

New Orleans, Louisiana is extremely prone to flooding for a variety of reasons. First, the city itself sits at the base of a bowl. The city itself is an average of about 1 to 2 feet below sea level. Thus, water is prone to sitting in the bowl and not draining out. In addition, water is even more prone to entering the bowl of the city because the city has major bodies of water on either side. Lake Pontchartrain, Lake Borgne, and the Mississippi River surround the city and are actually elevated above the city, and are held back but natural and man-made levees (as displayed in the figure above from Gesch, 2007). Thus, when water is poured into those bodies of water, they overflow into the city and flood it. New Orleans is also located at the southeastern tip of Louisiana, so it is near the ocean, where the hurricane will strike it at maximum intensity.

LIDAR is light detection and ranging, and a method discussed in Gesch’s (2007) article. Geographical data, especially topographic data, is very important for the success of the response and recovery groups during a large-scale natural disaster. The availability of high-resolution and high-accuracy elevation data originated from the LIDAR technology made it easy for rescue crews to estimate the flooding in different parts of New Orleans from Katrina in 2005. The days immediately after the storm, it was easy to find the areas that were in the most need of rescue crews, and were the most flooded. It also assisted in estimating the actual floodwater volume contained in the city. There is even potential for the influences of both the depth and length of flooding to be calculated on diverse types of structures in New Orleans.

Furthermore, this data assists in ongoing and future studies about the impacts of the storm and storms like it, and any potential imminent hurricane impacts on the city. With articles and GIS methods implemented such as these, the loss of life and property can be mitigated as much as possible for hurricanes like Katrina in the coming years. 

Resources: 

Gesch D (2007). Topography-based analysis of Hurricane Katrina Inundation of New Orleans. In: Science and the storms: The USGS Response to the Hurricanes of 2005. United States Geological Survey, Reston

NOAA.gov

As we have seen many times GIS can be used in a variety of fields and serve as a useful tool. Once again GIS is used to help portray impactful data through maps. In this study libraries use GIS with US census data to present and analyze data in a new way. Combined with the data provided by the US Census, GIS is useful for libraries in the area of service planning. The goal was to analyze demographic and socioeconomic patterns through maps to then plan an outreach program. The libraries have a free telephone based consumer and patient health information service called (CAPHIS), the staff responds to calls by mailing packets of health information at the appropriate literacy level to the caller. This service provides a good alternative to those who my not have internet access or need additional assistance because of limited health literacy and socioeconomic disparities. Studies have shown that people of low socioeconomic background have low health literacy, which leads to poor health lifestyles. Studies have also shown that libraries provide valuable health information and those who use these libraries report positive health actions in their life style.

This study uses the US census data to pinpoint the presence of people 60 years and over, poverty status in the past 12 months by sex and age, and sex by age by ambulatory disabilities. GIS was used to graph the locations of the origin of the calls to CAPHIS. GIS was also used to graph the areas based on rate of ambulatory disabilities. The graph provided by GIS paired with the US senses data can be used to plan out service projects to spread awareness about library services to low socioeconomic areas to improve health literacy amongst the community.

GIS is used in this study to create an action plan to improve the health of communities who do not have a well versed background in health literacy. GIS has once again proven to be a helpful tool in improving society.

Socha, Y. M., Oelschlegel, S., Vaughn, C. J., & Earl, M. (2012). Improving an outreach service by analyzing the relationship of health information disparities to socioeconomic indicators using geographic information systems. Journal of the Medical Library Association: JMLA, 100(3), 222.

In the University of Technology in Austin, GIS technology was used to determine the most efficient locations to place solar panels. The technology chosen to do this was LiDAR, or Light Detection and Ranging. Additionally, reverse topography was used to focus on the man-made structures to place the solar technology. The UT GIS staff wanted to have solar panels on the rooftops of the buildings so the dimensions of the roofs were isolated so that the solar energy potential was focused on the rooftops. Certain buildings, however, were not considered for rooftop panels. These include historically important buildings and buildings that already use their rooftops. Three main maps were used in determining the solar radiation. The first is the viewshed map, which measures the visible sky, the sunmap, which measures the position of the sun across a period of time, and the skymap, which measures the parts of the sky that affect the amount of incoming solar radiation.     

Since $12.25 is the break even point per square meter, UT can afford to spend $122.50 per square meter assuming the cost to install a solar PV is $1.40/Wh. Over the last 30 years the price of solar is ten times less than it was originally. By the year 2020, the price is predicted to be cut in half from the current price.

Sounny-Slitine, M. (n.d.). Potential of Solar Power on the University of Texas Campus.

Tweet Me Your Talk: Geographical Learning and Knowledge Production 2.0

We live in an age where we are on constant information overload.  All the important news of the day can be obtained on one page, in a few sentences rather than a few pages.  The latest neuroscience shows that not only is how we get information changing, but how our brains process information is changing as well.  We expect to obtain knowledge quickly and we have a short attention span. People are far more likely to read a tweet or watch/listen to a podcast than to read an entire article.  Research shows that readers bounce around pages and scan for important words when reading articles.  Even highly trained and well-read academics do not feel as though they have time to read entire articles.

This has several implications for the future of geographic research and knowledge.  First, the distracted, internet-heavy style of learning that leads to a short attention span for knowledge acquisition is available mostly to rich countries.  Almost all people have some internet access in the United States, while around half do in Russia and far fewer in Africa.  Second, research can reach a mass audience without rigorous fact checking and sourcing of its information.  Many sites that host academic articles have ways of putting the most read, viewed, and shared articles first.  This makes it easier to get to the most relevant information, but it discourages individual research and leads to groupthink.  Finally, in a positive way, articles are becoming more interactive.  As shown in Figure 2, Science articles feature links to supporting materials and podcasts with the authors in addition to the text article.  The journal Progress in Human Geography’s website offers pop-up abstracts available by hovering the mouse clicker over the link.  Also, many journals and authors post tweets about their work, reducing a complex research article down to 140 characters.

The acknowledgement of humans’ limited attention span and capacity is not a new one in spatial geography.  A general cartographer’s rule has always been to keep legend items from between 5-7, since this is what science suggests is the most information a brain can retain.  Part of the fear might just be, however, that many geography readers won’t get to the map at all when processing information.  It might be summed up in a tweet or easier to read article.  Articles will be increasingly shorter and offer more boxes and graphics to show the key points.  Based on the suggestions of this article, we will likely be seeing more and more simplified maps that cut out all extraneous information that disrupts the flow of readers’ “ADD” minds.

Schuurman, N. (2013). Tweet me your talk: Geographical learning and knowledge production 2.0. The Professional Geographer, 65(3), 369-377.

Land Change

It is crucial to study the global impact of land change because over the last recent decades, humans have been responsible for changing the global environment. This continues to be more of a concern as the population on Earth increases more and more. So it is necessary to understand how land change affects the environment, what socio-economic causes affect it as well as how it affects processes that affect global change. With agriculture and forestry, humans have been a significant reason that many landscapes have been completely modified and have impacted other creatures or plants that depend on these landscapes. The demand for these resources also grows because of the growing human population. Some social systems have attempted and been successful when dealing with land change and climate changes. People in wealthier countries are “buffered” from the impacts of climate change more so than people in third world countries. Many natural inputs like water or energy, have been modified by climate change and will continue to as rainfall and temperature patterns fluctuate in the coming years. These land changes could increase the exotic creature population by affecting the natural habitat of a certain landscape. Irrigated and non-irrigated cropland would be an example of how landscape changes due to land use practices. In the coming years, people will be more challenged to meet their needs for their resources while being as sustainable as possible and responding to these global environment changes effectively.

Ojima, D. S., Galvin, K. A., & Turner, B. L. (1994). The global impact of land-use change. BioScience, 300-304.

Free PASSaGE Software is Useful for Spatial Analysis

Michael Rosenberg and Corey Anderson from Arizona State University wrote an article for the Methods in Ecology and Evolution journal in 2011. Their article consists of an analysis about PASSaGE or the software for Pattern Analysis, Spatial Statistics and Geographic Exegesis. This tool is used for retrieving spatial stats. The software is free and easy to use and has been updated over the years. This is important to Rosenberg and Anderson as spatial analysis is not currently focused on in current GIS software. The PASSaGE program was created so that everyone could have access to the tools. Both PASSaGE’s (PASSaGE and PASSaGE 2) have been used in scientific research and in classrooms in order to help students and researchers better understand the data they are receiving. The PASSaGE program is comparable to other spatial tools currently available such as ArcGIS. The data for PASSaGE can be projected in one, two, or three dimensions. Rosenberg and Anderson then go on to describe the interface, graphics, and availability associated with PASSaGE. The interface was designed for Windows specifically though there have been versions made to run on Linux and Mac. The graphics are strong and PASSaGE 2 contains a graphical editor. The authors also discuss how data is input and extracted from the program. Data is able to be implemented into the program using shapefiles, spreadsheets, and text files. The authors conclude by saying that the PASSaGE software is important as it allows anyone to have free access to geographic analysis using spatial statistics.

This is an example of the graphical output produced by the second PASSaGE software package. In this graph a surface map with elevation data is shown. The color gradient scale is presented alongside it in order to help the viewer understand the graph. The numbers are in increments of 5 on the y axis, and increments of 10 on the x axis. The color scale is presented in increments of 1,000. This is only one demonstration of the major classes of methods, the creation method, present inside the PASSaGE software.

Rosenberg, M. S., & Anderson, C. D. (2011). PASSaGE: pattern analysis, spatial statistics and geographic exegesis. Version 2. Methods in Ecology and Evolution, 2(3), 229-232.