Dynamic Maps: Showing Change over Time
One of the most powerful ways to use GIS techniques to show and understand how our world changes is to factor in the passage of time in our maps. As you probably recall, Hurricane Katrina had a devastating eﬀect on the physical landscape of New Orleans, coastal Mississippi, and parts of Alabama in September 2005, but it was perhaps in the city of New Orleans itself where the devastation became best known to Americans elsewhere in the country and to the entire world. One of the tragedies of this hurricane and its aftermath was the way in which poverty, especially among African-American residents in New Orleans, left many people vulnerable and stranded. One question to ask about this is how did certain parts of the city end up being populated by poor people with few resources to deal with this disaster? Is this something that was always the case, and no one realized the problematic nature of the situation because New Orleans was very lucky during the past 40 years and had experienced no direct hits by such a power storm as Katrina? Did this situation develop recently, and therefore local residents and oﬃcials alike could not have anticipated the problems that might result? Issues like these are of dire importance to examine when planning for disaster relief. One way to examine this question is to map the rates of poverty among African-American residents in New Orleans over time and see if any patterns emerge that might illuminate the tragic situation and help New Orleans, other cities, and the Federal government plan more eﬀectively for future storms hitting major urban centers.