GGR374H5 Lecture Notes - Lecture 4: Baseflow, Denitrification, Nitrogen Cycle
Document Summary
Riparian zone the area of land adjacent to streams and rivers, zone of transition between terrestrial and aquatic environments significant potential to regulate the chemistry of overland and subsurface flows. Head water riparian zones in humid landscapes have the most extensive interactions between land surfaces and aquatic systems. Element inputs from adjacent uplands are influenced by the magnitude and seasonality of the groundwater flow to the riparian zone riparian zones function as the immediate source of groundwater, which sustain stream baseflows during storm periods. During stream base flows, considerable differences in nitrate and ammonium in subsurface water frequently occur riparian zones function as net sources of nitrate during high flows because rising water table flushes out nitrate. Declines in nitrate in anoxic riparian zone subsurface water have been attributed to denitrification, and ammonification increased ammonium. Denitrification only occurs in oxygen limited environments saturation overland flow from riparian wetlands may also influence stream nitrogen chemistry during larger summer and autumn storms.
