Interaction of esker groundwater with headwater lakes and streams

JOURNAL OF HYDROLOGY

卷:500

Article

Ala-aho, Pertti¹  Rossi, Pekka M.¹  Klove, Bjorn¹ 

[1] Univ Oulu, Dept Proc & Environm Engn, Water Resources & Environm Engn Lab, Oulu 90014, Finland

关键词: Groundwater-surface water interaction;    Seepage meter;    Natural tracers;    Groundwater flow systems;   

DOI  :  10.1016/j.jhydrol.2013.07.014

来源: Elsevier

【 摘 要 】

Groundwater-surface water interactions were studied in a Finnish esker aquifer system where some lakes suffer from periodic water level decline and others from eutrophication. Natural tracers (Ca2+, SiO2 and PO43-) were used on the aquifer scale and seepage meter measurements and water level recordings on the single lake scale to better understand the complex interactions between groundwater, lakes and streams in the area. The natural tracers showed that lakes located in lower landscape positions and connected with streams were richer in tracer concentrations and that their water chemistry resembled that of the groundwater. On the other hand, closed basin lakes located at higher altitudes were nutrient-poor seepage lakes with some groundwater through flow. The data suggests that the subsurface acts as a phosphate source for the surface water bodies and the nutrient rich groundwater inseepage dictates the trophic status of the lakes in the area. The seepage meter measurements verified a strong interaction between groundwater and surface water and revealed spatial distribution of lake seepage and a temporal co-variation in lake seepage rates. A statistical analysis of seepage meter and water level observation time series were useful to show groundwater flow regimes controlling lake seepage. Using the natural tracer analysis and seepage meter measurements, we developed a novel conceptual model for the study site where the differences in lake trophic state and water table behavior were explained by assigning lakes to local and regional groundwater flow regimes. The obtained results provide new knowledge on using natural tracers in complex glacial aquifer systems and can be used in integrated groundwater-surface water management. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free