|Gburek W J,|
Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: December 14, 1993
Publication Date: N/A
Interpretive Summary: Not required.
Technical Abstract: Effects of land use distribution on ground water quality were examined within the layered and fractured aquifer of a small upland agricultural watershed in east-central Pennsylvania. Geometry and hydraulic properties of the aquifer have been characterized by a variety of field and modeling research efforts. Ground water modeling based on these characterizations was extended to examine patterns of contaminant transport in areal and cross section formats. Flowpath analyses indicated that the watershed scale ground water flow system is comprised of smaller units of flow relatively self contained at the scale of second order streams. This finding allowed more detailed analyses to be done in a cross section format. The EPIC root zone model was used to simulate percolate quality representing land use distribution over typical watershed and local scale cross sections. Using the distribution of percolate quality as input, a contaminant transport model simulated resulting patterns of ground water quality. Land use over the upland positions of the watershed controls ground water quality within the regional aquifer, while land use over the remainder of the watershed affects water quality only within the shallower layers of the aquifer. In near-stream zones, water quality within the shallower layers is a mix of ground water inflows from upslope and from the regional aquifer discharging upward toward the land surface. The simulations show the potential for contamination of ground water and nonstorm streamflow by agricultural land use, as well as the potential to control contamination of targeted portions of the subsurface flow system by control of land use positioning