3:48 p.m., Dec. 16, 2008----It is one of the most densely populated and poorest countries on Earth. And unfortunately for Bangladesh, sea-level rise could make it one of the most affected by climate change.
If the sea rises one meter, as is projected, approximately 17 percent of the country's land area will be inundated and millions of people will lose their homes. The rising sea also would threaten the country's groundwater, which residents rely on for everything from agriculture to drinking water.
“When sea level rises or storm surges flood coastal areas, brackish water intrudes into aquifers, compromising the fresh water resource,” said Holly Michael, assistant professor of geological science. “When you start thinking about effects of climate change, the sustainability of the water supply could be jeopardized.”
Michael, who joined the College of Marine and Earth Studies (CMES) in September, has made a career of understanding groundwater and surface water interactions.
“I'm interested in how much groundwater flows into the sea and the physics of how it works -- what processes drive flow in and out of aquifers,” she said, explaining that a “great hydrogeology professor in undergrad” spurred her interest in the field.
After she got her bachelor's degree in civil engineering at the University of Notre Dame, Michael earned a doctoral degree in hydrology from the Massachusetts Institute of Technology. Most recently, she completed post-doctoral training with the U.S. Geological Survey (USGS) and then Stanford University.
It was at USGS that she began developing a keen understanding of the groundwater situation in Bangladesh. She worked on a project there researching arsenic in the groundwater and investigating alternative water sources that lack the contaminant.
Now she's researching the vulnerability of groundwater to coastal sea level rise there. The project is part of a larger World Bank effort to understand the potential effects of climate change on food security in Bangladesh.
Michael also is keeping busy with several other projects, one of which is aimed at creating a classification system to help experts see how different types of coastal systems will be affected by sea level rise and changes in temperature and precipitation.
She said the system could help coastal managers plan for future changes in hydrology.
“With the classification system you can say, OK, we have this type of geology with this type of topography and these levels of precipitation; this is the type of vulnerability we might expect,” she said.
Michael also is interested in how groundwater flow affects coastal ecosystems. She explained that groundwater flowing into coastal surface waters can carry high levels of nutrients from human land use -- sources such as septic systems and agriculture.
When nutrient levels increase too much, they fuel an overgrowth of algae, which robs bays and estuaries of oxygen and threatens marine life. Such nutrient concentrations degrade the ecosystem in both the Chesapeake and Delaware Inland Bays.
“I am interested in how much groundwater flows directly into estuaries, and how groundwater flowpaths and interactions with surface water lead to chemical reactions in the subsurface that affect nutrients entering these estuaries,” she said.
In addition to her research, Michael, who is originally from Aliquippa, Pa., said she's excited about working with students and having a field site a short car ride away at the Hugh R. Sharp Campus in Lewes. The University of Delaware, she said, is a great fit.
“It's really exciting to have a lot of people in the geological sciences department and also in the college and the university doing similar research, who are interested in your work, and contributing to solving different aspects of the same problems,” she said.
For more about the College of Marine and Earth Studies, visit the web site.
Article by Elizabeth Boyle