My research is primarily in association with graduate students and addresses a number of areas of hydrogeology. The behavior of major aquifer systems with development has long been of interest. Another interest, surface water/ groundwater interaction, ranges from studies of induced recharge of wellfields adjacent to rivers to development of stream drainage systems by groundwater sapping. Temperature and atrazine tracers have been used to quantify movement of induced recharge into city wellfields and provide dispersion values for alluvial aquifers. Studies of the role of groundwater sapping include erosion of riverbanks in southeastern Nebraska, development of the Dismal River valley in the Nebraska Sandhills and associated boiling-sand springs, the formation of convex waterfalls along the Niobrara River in northern Nebraska and Hawaii, and cybernetics of weathering processes. Additional work has involved the development of quantitative concepts for the formation of stream drainage patterns by groundwater sapping and causes of stream piracy. An intriguing project involves the discovery that changes of baseflow in the Dismal River are negatively correlated to changes of barometric pressure.
Selected Publications
- Pederson, D.T., 2001, Stream piracy revisited: a groundwater sapping solution, GSA Today, 11(9), 4-10.
- Pederson, D.T., 2000, Effect of semi-perched ground water on monitoring of groundwater levels in a developed aquifer, Journal of the American Water Resources Association, 36, 1367-1374.
- Davis, R.K., and Pederson, D.T., 1996, Patterns of ground-water level decline in developed aquifers, Water Resources Bulletin, 32, 107-115.
- Tabidain, A. M. and Pederson, D.T., 1995, Impact of irrigation wells on baseflow of the Big Blue River, Nebraska, Water Resources Bulletin, 31, 295-306.
- Davis, R.K., Pederson, D.T., Blum, D.A., and Carr, J.D., 1993, Atrazine in a stream-aquifer system: estimation of aquifer properties from atrazine concentration profiles, Ground Water Monitoring and Remediation XIII, 134-141.