AP Science Writer
WASHINGTON (AP) -- Many states get hit frequently with tornadoes and other natural catastrophes, but Oklahoma is Disaster Central.
The twister that devastated Moore, Okla., was the 74th presidential disaster declared in the Sooner state in the past 60 years. Only much-larger and more-populous California and Texas have had more.
The state is No. 1 in tornado disasters and No. 3 for flooding, according to a database of presidential disaster declarations handled by the Federal Emergency Management Agency. And those figures don't include drought, which is handled by a different agency.
The explanation is partly atmospheric conditions that trigger twisters and flooding, partly where people live and how they build their homes, and partly politics and bureaucratic skill, according to disaster experts. Even one of the state's U.S. senators said recently that because of the way federal guidelines are written, Oklahoma is getting disaster aid more often than it needs.
Of the 25 U.S. counties that have been declared disasters the most times since 1953, nine are in Oklahoma, the highest total of any state.
Oklahoma County has been on the disaster list 38 times, more than the entire state of New Jersey. Caddo County, just west of the Oklahoma City metro area, has been named a federal disaster area nine times since 2007, with a litany of woe that includes twisters, floods, ice storms, a blizzard and violent winds.
"Things happen around here," Tulsa, Okla.-based disaster consultant Ann Patton said. "Of course, sometimes it can make you stronger."
When disaster declarations are measured on a per-person basis, Oklahoma gets nearly three times the national average. When they are computed based on how much land is in a state, it gets twice the national average, according to an analysis of FEMA records.
The atmospheric explanation is pretty basic: "Oklahoma really is the bull's-eye for awful tornadoes," said Mike Lindell, director of the Hazard Reduction and Recovery Center at Texas A&M University.
Oklahoma is in a particularly busy and dangerous section of Tornado Alley, the cluster of states in the nation's midsection that are especially twister-prone.
If you map all the nation's tornadoes in May -- the busiest tornado month -- they form a circular blob 100 miles across over central Oklahoma. That's because low-pressure systems rush south down the Rocky Mountains and collide with warm, moist air, forming nasty thunderstorms that often spawn tornadoes, said Harold Brooks, a research meteorologist at the Severe Storms Laboratory in Norman, Okla.
"Welcome to the sweet spot of severe thunderstorms," Brooks said.
Texas, Kansas and Florida get more tornadoes than Oklahoma does, according to the National Oceanic and Atmospheric Administration. But Oklahoma gets more of the biggest ones -- the EF5s, like the one that smashed Moore. That's why the storm lab and the National Weather Service storm prediction center are in Oklahoma, Lindell said.
With severe thunderstorms, you can get both tornadoes and flooding. Oklahoma has been declared a disaster 35 times because of tornadoes and 44 times because of flooding. In some instances, a combination tornado-and-flood disaster was declared.
The FEMA database looks only at how often catastrophes are declared and aid is shipped, not at how much total money is given out.
Tornadoes generally occur more frequently than hurricanes and earthquakes but usually don't cause as much damage. Oklahoma City officials estimate the Moore tornado caused up to $2 billion in damage, while state officials say it may exceed the figures for the 2011 Joplin, Mo., tornado. At $2.8 billion, Joplin is the nation's costliest tornado since 1950, according to NOAA.
Yet NOAA's National Hurricane Center lists more than 30 hurricanes that caused more than $2.8 billion damage when adjusted for inflation. Hurricanes tend to hit broader areas, last longer and strike the more densely populated coast, where property values are higher.
Another explanation for Oklahoma's role as Disaster Central is urban sprawl, which puts more people in the path of disasters. Moore, with 56,000 people, boomed by more than one-third between 2000 and 2010. As more such suburbs pop up and grow, the chances of homes being hit increases.
Between 1970 and 1985, Tulsa County was declared a flood disaster about nine times, said Patton, the disaster consultant. Then the city moved more than 1,000 buildings out of harm's way and diverted water. There hasn't been major flooding since, she said.
Oklahoma is the leading state when it comes to safe rooms, which probably saved lives in Moore, according to FEMA. Yet some areas haven't developed wisely to avoid disasters and "don't respect the power of nature," Patton said.