High Plains Journal, KS
05-04-07
ISU researchers design shelterbelts to protect against tsunamis
Iowa
Iowa State University researchers are applying their knowledge of agricultural
shelterbelts to protect coastal areas from tsunamis at the request of the United
Nations' Food and Agriculture Organization.
Following the devastating aftermath of Hurricane Katrina and the December 2004
tsunami in Southeast Asia, many international planning agencies have searched
for ways to prevent such tragedies in the future. Gene Takle, professor of
agronomy and geological and atmospheric sciences, and colleagues Mike
Chen and Xiaoqing Wu in atmospheric science were asked to develop a set
of guidelines for rebuilding coastal forests based on their research on wind
reduction by the use of agricultural shelterbelts.
The ISU group was commissioned to write a paper on designing coastal forests
and shelterbelts, which are known as "bioshields." Takle represented the group
at a workshop under sponsorship of the FAO last summer in Khao Lak, Thailand,
where hundreds of bodies had washed up on the beach after the 2004 tsunami.
"Much loss of life from this tsunami was attributed to destruction of coastal
forests. Villages in India and Southeast Asia that preserved their coastal
mangroves suffered far less damage," Takle said. "FAO requested guidelines for
rebuilding these bioshields based on our work and understanding of agricultural
shelterbelts."
Their suggested guidelines include planting trees as close to the sea as possible;
using short salt-tolerant and sparse shelters on the seaward edge; using tall
species of high wind resistance on the landward side; and leaving gaps between
rows and irregularly within the rows to extend the protected zone, but allowing for
onshore flow of the cooling sea-breeze in nonhazardous conditions.
"Very little research has been done on this topic, so we used our computer model
and previous experience on flow through living barriers to evaluate alternative
shelter designs like tree heights, density, spacing and orientation to develop our
recommendations," Takle said.
Federal managers in Southeast Asia and India will consider the guidelines when
rebuilding damaged coastal areas.
Takle has teamed with meteorology graduate students Dan Rajewski and Sarah
Schmidt to conduct additional studies to refine the preliminary guidelines he
presented at the Thailand workshop and explore additional uses of bioshields
against high winds.