Precipitation, snowpack, stream-water ion chemistry, and flux...

来自 : www.onacademic.com/detail/jour 发布时间：2021-03-24

Author: Stottlemyer, RToczydlowski, D

Journal: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES

Issue Date: 1996

Abstract(summary):
Input-output budgets, snowpack ion content and loss, and change in stream-water chemistry during snowmelt were quantified for 10 years in a small watershed in upper Michigan. Annual precipitation (centimetres) and H+ and SO42- inputs declined during the decade. Precipitation SO42- concentration decreased, with two thirds of the decline occurring in winter. Winter precipitation and H+, NH4+, NO3-, and SO42- inputs declined during the decade. Reduced precipitation SO42- concentration accounted for a third of the reduction in winter SO42- input. Up to snowpack peak water equivalent, snowmelt totalled one third and ion loss totalled 37-58% of cumulative precipitation inputs. Midwinter snowmelt was attributed to unfrozen soils and intermittent thaws. About 90% of snowmelt entered unfrozen soil, where soil processes significantly altered its chemistry. The watershed retained >99% of snowmelt H+, >95% of NH4+, and >80% of NO3-. At peak snowmelt, stream-water acid neutralization capacity declined by 360 mu equiv. L(-1), with >90% resulting from dilution. Stream-water NO3- concentration declined >85% during snowmelt and SO42- concentration changed

Page: 2659---2672


Input-output budgets, snowpack ion content and loss, and change in stream-water chemistry during snowmelt were quantified for 10 years in a small watersh...onAcademic ；Science；Technology；Medicine；researchInput-output budgets, snowpack ion content and loss, and change in stream-water chemistry during snowmelt were quantified for 10 years in a small watershed in upper Michigan. Annual precipitation (centimetres) and H+ and SO42- inputs declined during the decade. Precipitation SO42- concentration decreased, with two thirds of the decline occurring in winter. Winter precipitation and H+, NH4+, NO3-, and SO42- inputs declined during the decade. Reduced precipitation SO42- concentration accounted for a third of the reduction in winter SO42- input. Up to snowpack peak water equivalent, snowmelt totalled one third and ion loss totalled 37-58% of cumulative precipitation inputs. Midwinter snowmelt was attributed to unfrozen soils and intermittent thaws. About 90% of snowmelt entered unfrozen soil, where soil processes significantly altered its chemistry. The watershed retained >99% of snowmelt H+, >95% of NH4+, and >80% of NO3-. At peak snowmelt, stream-water acid neutralization capacity declined by 360 mu equiv. L(-1), with >90% resulting from dilution. Stream-water NO3- concentration declined >85% during snowmelt and SO42- concentration changed <10%. Soil SO42- desorption was probably the major process buffering change in stream-water SO42- concentration.