TY - JOUR T1 - EPIC modeling of the effects of farming practice changes on water quality in two Lake Erie watersheds JF - Journal of Soil and Water Conservation SP - 85 LP - 90 VL - 55 IS - 1 AU - D. L. Forster AU - R. P. Richards AU - D. B. Baker AU - E. N. Blue Y1 - 2000/01/01 UR - http://www.jswconline.org/content/55/1/85.abstract N2 - Agriculture's contributions to Lake Erie water quality problems have been a concern for the past three decades. This research investigates the relationship between changes in water quality and changes in farming practices in two Lake Erie tributaries. Using the Erosion Productivity Impact Calculator (EPIC), simulations of pollutant emissions from farms in the Maumee and Sandusky River basins were conducted with 1985 and 1995 land use and cropping patterns. This infarmation was compared with unit area load derived from detailed water quality data collected at integrator stations near the mouths of the two rivers. The comparison showed large differences between the two data sets that cannot be explained by errors of load estimation, errors in application of the EPIC model, or differences between the modeled and monitored parameters. Rather, discrepancies in results are likely due to the fact that EPIC does not model in-stream delivery losses, and the observed loads are affected by these losses. However, EPIC simulations are generally accurate in predicting the direction of change of unit area loads of water quality parameters. ER -