Dr. Durga Poudel, assistant director of the School of Geosciences at UL Lafayette, grew up in the mountainous region of Nepal, tending buffalo, goats, crops and fruit trees with his younger brother.
His father farmed a plot of land. His mother worried a lot, Poudel said, particularly during monsoon season. That’s when heavy rains would tear the family’s food supply from the ground and wash it away.
That experience prompted him to study agriculture, natural resources and soil science at universities in Nepal, Pakistan, Thailand and the United States. Today, he’s regarded as an international expert in soil and water conservation, water quality, climate change and sustainability.
Poudel led a team of researchers who conducted a six-year study to measure how agricultural production impacts water quality along the Bayou Plaquemine Brulee Watershed. Results were published in an academic journal this summer.
The watershed has been on Louisiana’s list of impaired water bodies, or those that don’t meet state water quality standards, since 1998.
Researchers collected surface water samples along a 20-mile stretch of the watershed every 15 days between 2002 and 2008. The watershed spans Church Point and Estherwood, two small communities in southwestern Louisiana.
Computer models were used to identify nonpoint source pollution “hotspots” in the watershed. Water quality data such as surface water temperature, dissolved oxygen levels, biological oxygen demand, the presence of nutrients and chemicals, and pH levels were analyzed.
“The idea was to determine how water quality differs from season to season, and what are the factors that cause differences in water quality. After we determined that, we wanted to find hotspots, the critical areas contributing to nonpoint source pollution,” Poudel said.
Sediment, nutrients and dissolved solids were key factors that affected water quality.
“The lower part of the watershed was worse because of agricultural practices in rice and crawfish production,” Poudel said.
In 2011, he went back to Nepal to lead another research team on an 18-month project to research issues of water availability, soil quality and diseases. The researchers’ work was part of an effort to improve livestock health and agricultural productivity for more than 350 households on the Thulokhola watershed in the region where Poudel grew up.
In Nepal, more than 23 million people, or about 80 percent of the population, depend on agriculture for their livelihood. Drinking water is critical in Nepal since climate changes are drying up water sources.
“Pinpointing causes of degraded water quality and identifying hotspots helps government or industry focus resources to help improve water quality in critical areas,” Poudel said.
Results from such studies are useful in developing sound conservation plans and land management techniques.