GROUNDWATER-SURFACE WATER INTERACTIONS IN A HEADWATER STREAM: EAST FORK, JEMEZ RIVER, NM
As part of a Research Experience for Undergraduates (REU) funded by the National Science Foundation (NSF) and New Mexico EPSCoR, 34 shallow monitoring wells were installed in the hyporheic zone of the East Fork Jemez River in the Valles Caldera National Preserve during the summer of 2010. Water quality was sampled and analyzed in all wells and at two surface water locations. Continuous water quality sensors (T, pH, conductivity, dissolved oxygen (DO), depth) were deployed in selected wells and the adjacent stream. Field parameters and water levels were also measured multiple times through the summer of 2010. Additional sampling took place in the summer of 2011 before the Los Conchas fire and sampling has continued to take place after the fire. In general, pH is consistently lower in groundwater (GW) relative to surface water, and DO concentrations are consistently <1 mg/L in GW regardless of stream proximity. Specific conductance is either equal or higher than contemporaneous stream values. The significant diurnal variability observed in surface water DO, T, and pH is not observed in GW data. These data are important for understanding reactions in the hyporheic zone.