Fine‐scale characteristics of groundwater flow in a peatland

Fine-scale dynamics of groundwater flow were studied in a 1·5 ha peatland in central New York. Measurements of the hydraulic head throughout a detailed network of piezometer clusters revealed spatial and temporal variability in the direction of groundwater flow at a very fine (within a few metres) scale of analysis. Within the small wetland, there were areas of groundwater recharge, discharge and lateral flow. Such patterns of groundwater flow frequently reversed or changed due to fluctuations of only a few centimetres in hydraulic head. Specific conductance, deuterium signatures and calcium concentrations of groundwater corroborated the groundwater flow patterns determined with hydraulic head measurements and illustrated the influence of source water chemistry and evaporation on different layers in the peat column. The control of peat chemistry by such fine-scale groundwater flow may have important implications for plant community composition and diversity in groundwater-fed peatlands. Copyright © 1999 John Wiley & Sons, Ltd.