Models are needed that describe how topography and other watershed characte
ristics affect the chemical composition of runoff waters, yet little spatia
lly distributed data exist to develop such models. A topographically driven
flushing mechanism for nitrate (NO3-) and dissolved organic carbon has bee
n described in recent literature; however, this mechanism has not yet been
thoroughly tested. A 24 ha catchment in the Catskill Mountains of New York
was clearcut in the winter of 1996-97, resulting in elevated NO3- concentra
tions in soil water, groundwater and streamflow. We sampled shallow subsurf
ace stormflow (SSSF) and streamflow six times during the spring and summer
of 1998, 1 year after the harvest. We used a spatially distributed network
of piezometers to investigate the relationship between topography and SSSF
chemistry. Several indices of topography were computed, including the commo
nly employed topographic index of Beven and Kirkby (1979; Hydrological Scie
nces Bulletin 24: 43-69). Topographic index was positively correlated with
NO3- concentrations in SSSF. The strength of the NO3--topography relationsh
ip was best explained by antecedent soil temperature and antecedent precipi
tation conditions. Results suggest a topographically driven flushing of hig
h NO3- shallow soil at the site during storm events. Copyright (C) 2001 Joh
n Wiley & Sons, Ltd.