| A novel design of
lysimeter for use in mires (peatlands) with shallow water tables is described.
It employs an hydraulic mechanism for the automatic
equilibration of soil moisture distribution between the outside and the inside
of the lysimeter tank but uses no electronic components or
electrical power; and it can be installed with minimal disturbance in surfaces
with poor load-bearing capacity. The system was deployed on a
mire in northern Scotland to investigate the distribution of shallow seepage
associated with catenary arrays of different types of surface (microtopes).
During the three-year period 15 November 1988 to 19 November 1991, the fraction
of rainfall dispersed as seepage was 52% in a pool system;
62% in ridge-furrow microtopography; and 59-67% in unpatterned sloping mire. The
data provide preliminary confirmation of the hypothesis of
K. E. Ivanov that different microtopes within the same mire differ in their
hydrological norms; and suggest that the range of
ecohydrological differences at the study site may be similar to those obtained
by Ivanov in western Siberia. Details of lysimeter design, construction,
installation and operation are appended together with a discussion of the theory
of the lysimeter.
Keywords: acrotelm, blanket mire, ecohydrology, evapotranspiration, pool system,
valleyside flowe, water balance |