At St. Anthony Falls Laboratory, graduate student Michal Tal studies the effect of riverbank vegetation on stream flow, sedimentation, and channel formation. Here she uses a laboratory channel containing alfalfa and a stream of water infused with environmentally safe red dye.
Forces of nature
University scientists and engineers are finding ways to better understand, predict, and manage nature's dynamic powers
By Rhonda Zurn
March 15, 2006
Last year's headlines stunned us with their litany of natural disasters:
TSUNAMI IN INDIAN OCEAN KILLS MORE THAN 200,000 PEOPLE
IN 11 COUNTRIES
HURRICANE KATRINA KILLS MORE THAN 1,000 AND DISPLACES MORE THAN A MILLION
HURRICANE RITA DESTROYS MORE THAN 35,000 HOMES AND KILLS UP TO 100
DEVASTATING EARTHQUAKE IN PAKISTAN KILLS MORE THAN 79,000 AND INJURES 75,000
The scope of these disasters shocked even the scientists and engineers most familiar with nature's destructive powers. For many researchers at the University of Minnesota, the events also fortified their resolve to find better ways to manage disasters, improve infrastructures, and save lives.
At the Institute of Technology's St. Anthony Falls Laboratory, University researchers conduct experiments to learn more about our environment and human impact on it.
"While we humans have learned how to change our environment, it's obvious we haven't been very successful in fully controlling it," said Chris Paola, director of the University's National Center for Earth-surface Dynamics (NCED).
Paola's research has focused on the Mississippi River and changes in the earth's surface in relation to natural deposits of sediment. Management of sediment along the river, intended to improve shipping navigation, has left the coastal area more vulnerable to hurricane damage.
"New Orleans is right on the edge of the water," Paola said. "If we would've allowed sediment to form more deltas, this low-lying land may have helped absorb some of the force of Hurricane Katrina."
Better evacuation planning also could have lessened the death toll from Katrina, said Shashi Shekhar, director of the Institute of Technology's Army High Performance Computing Research Center. With support from the Army Research Laboratory and the Minnesota Department of Transportation, Shekhar and other researchers are developing more efficient evacuation route plans.
"Our research here at the University shows that cities can improve existing emergency plans by using computerized tools such as evacuation route planning software."According to Shekhar, the problems in New Orleans were exacerbated by several factors: insufficient planning and resources for responding to levee breaches, for evacuating people needing assistance, and for getting information to decision makers. Miles-long traffic jams on Texas freeways during the Hurricane Rita evacuation also exposed the limitations of the transportation network and the inadequate evacuation route planning.
"I do not want to be a 'Monday-morning quarterback.' However, it would have been useful if decision makers had fully funded and completed planning for catastrophic events, such as the levee breach in New Orleans, even if the probabilities were small that they would occur," Shekhar said.
He is a strong advocate of using new technologies to upgrade disaster preparedness.
"Our research here at the University shows that cities can improve existing emergency plans by using computerized tools such as evacuation route planning software," Shekhar said. "In addition, computerized software tools allow cities to examine the interaction among emergency plans of neighboring cities. This is especially critical in large metropolitan areas with multiple cities and townships."
Better forecasting will improve preparedness, and well-managed evacuations can save lives, but the scale of a disaster is determined in part by other factors, said Justin Revenaugh, a professor of geology and geophysics.
People live in seismically active zones and in locations prone to other types of natural disasters because these areas are often naturally beautiful and agriculturally fertile as well, he said.
"These are not bad places to build, provided you build smart," he added. "It's all about building style and quality and population density--primary factors in earthquake fatalities."
Arturo Schultz, an associate professor of civil engineering, has done extensive research on unreinforced masonry walls (no steel reinforcement within the mortar joints or grouted internal cavities). Such construction, common in Pakistan, India, and other parts of the world, has very little resistance to earthquake forces, according to Schultz.
"Upon reaching their load capacity, improperly designed, unreinforced masonry buildings are prone to collapse, making this form of construction extremely hazardous," he said.
Schultz has witnessed firsthand the damage that strong earthquakes can inflict on other types of building structures in countries around the world. He was in Turkey following the 1999 earthquakes and in Mexico City after the 1986 earthquake. On both occasions he saw evidence of structural failure.
In his capacity as chair of the Masonry Society's Investigating Disasters Program, Schultz has organized and coordinated teams of masonry experts who investigated the effects of earthquakes and tornadoes on masonry construction.
"These observations have allowed us to identify many commonalities in the patterns of damage and failure to masonry structures during earthquakes and sustained high-velocity winds," Schultz said.
The structural engineering technology used to build stronger buildings in the U.S., Japan, New Zealand, Canada, Western Europe, and other industrialized regions would save lives if used in developing countries, but the cost is often prohibitive.
Researchers at the University's Multi-Axial Subassemblage Testing (MAST) facility conduct large-scale structural testing and analysis, including model-based simulations, of the integrity of structures subjected to earthquakes and other extreme forces.
"That kind of structural engineering technology becomes a luxury that many developing countries cannot afford [because they have so many other needs]," Schultz said. "I think the United Nations, World Bank, U.S. government, European Union, and others should establish an international program to develop seismic-design solutions for developing nations--for example, economical solutions that can be implemented by individuals who do not have engineering and architectural design expertise, such as homeowners and small builders."
For one Institute of Technology alumnus, the impact of natural disasters on developing countries hit close to home.
"I was in Sri Lanka in December 2004 when the tsunami hit," said Suresh Hettiarachchi, a 1998 civil engineering graduate. Originally from Sri Lanka, he now works as a water resources engineer in the Minneapolis office of HDR Engineering, Inc.
"I was not staying in the hardest-hit area, but I soon heard about the devastation," he said. "It was unbelievable that in 15 minutes the tsunami killed more than 30,000 people in Sri Lanka and destroyed two-thirds of the country's coast. It really showed me the power of this tsunami and how nature can change things in an instant."
Hettiarachchi delayed his departure from Sri Lanka for three weeks in order to help with the relief and rebuilding efforts. He returned briefly to Minnesota to prepare for a longer trip, a 10-week leave of absence from his job to volunteer with the United States Agency for International Development. During that time he worked with the group to reconstruct water systems, roads, and other critical systems. In December 2005 he returned again to Sri Lanka to check on the progress and to find more ways to help.
"What really surprised me in the tsunami was the resiliency of the people to try again," he said. "I was also impressed with the overall level of planning to do things better and consider the environmental impact of their actions."
Hettiarachchi said the experience changed his life and confirmed his career path.
"I always considered myself an 'accidental engineer' because I never really planned to become an engineer," Hettiarachchi said. "My experience in the tsunami relief and rebuilding efforts made me feel better about being an engineer because I was able to clearly see that my skills were of real value to the people as they put their lives and their country back together again."
From Inventing Tomorrow winter 2006, a magazine for alumni and friends of the Institute of Technology.