TY - JOUR
T1 - Nutrient dynamics in an alpine headwater stream
T2 - Use of continuous water quality sensors to examine responses to wildfire and precipitation events
AU - Sherson, Lauren R.
AU - Van Horn, David J.
AU - Gomez-Velez, Jesus D.
AU - Crossey, Laura J.
AU - Dahm, Clifford N.
N1 - Publisher Copyright:
© 2015 John Wiley & Sons, Ltd.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Stream water quality can change substantively during diurnal cycles, discrete flow events, and seasonal time scales. In this study, we assessed event responses in surface water nutrient concentrations and biogeochemical parameters through the deployment of continuous water quality sensors from March to October 2011 in the East Fork Jemez River, located in northern New Mexico, USA. Events included two pre-fire non-monsoonal precipitation events in April, four post-fire precipitation events in August and September (associated with monsoonal thunderstorms), and two post-fire non-monsoonal precipitation events in October. The six post-fire events occurred after the Las Conchas wildfire burned a significant portion of the contributing watershed (36%) beginning in June 2011. Surface water nitrate (NO3-N) concentrations increased by an average of 50% after pre-fire and post-fire non-monsoonal precipitation events and were associated with small increases in turbidity (up to 15NTU). Beginning 1month after the start of the large regional wildfire, monsoonal precipitation events resulted in large multi-day increases in dissolved NO3-N (6×background levels), dissolved phosphate (100×background levels), specific conductance (5×background levels), and turbidity (>100×background levels). These periods also corresponded with substantial sags in dissolved oxygen (<4mgl-1) and pH (<6.5). The short duration and rapid rates of change during many of these flow events, particularly following wildfire, highlight the importance of continuous water quality monitoring to quantify the timing and magnitude of event responses in streams and to examine large water quality excursions linked to catchment disturbance.
AB - Stream water quality can change substantively during diurnal cycles, discrete flow events, and seasonal time scales. In this study, we assessed event responses in surface water nutrient concentrations and biogeochemical parameters through the deployment of continuous water quality sensors from March to October 2011 in the East Fork Jemez River, located in northern New Mexico, USA. Events included two pre-fire non-monsoonal precipitation events in April, four post-fire precipitation events in August and September (associated with monsoonal thunderstorms), and two post-fire non-monsoonal precipitation events in October. The six post-fire events occurred after the Las Conchas wildfire burned a significant portion of the contributing watershed (36%) beginning in June 2011. Surface water nitrate (NO3-N) concentrations increased by an average of 50% after pre-fire and post-fire non-monsoonal precipitation events and were associated with small increases in turbidity (up to 15NTU). Beginning 1month after the start of the large regional wildfire, monsoonal precipitation events resulted in large multi-day increases in dissolved NO3-N (6×background levels), dissolved phosphate (100×background levels), specific conductance (5×background levels), and turbidity (>100×background levels). These periods also corresponded with substantial sags in dissolved oxygen (<4mgl-1) and pH (<6.5). The short duration and rapid rates of change during many of these flow events, particularly following wildfire, highlight the importance of continuous water quality monitoring to quantify the timing and magnitude of event responses in streams and to examine large water quality excursions linked to catchment disturbance.
KW - Continuous monitoring
KW - Headwater streams
KW - Monsoonal storms
KW - Nutrient dynamics
KW - Water quality
KW - Wildfire
UR - http://www.scopus.com/inward/record.url?scp=84947870827&partnerID=8YFLogxK
U2 - 10.1002/hyp.10426
DO - 10.1002/hyp.10426
M3 - Article
AN - SCOPUS:84947870827
SN - 0885-6087
VL - 29
SP - 3193
EP - 3207
JO - Hydrological Processes
JF - Hydrological Processes
IS - 14
ER -