Current issue: 58(5)
The study discusses the amplitude of the simultaneous groundwater table fluctuations in different parts of pine mires, and factors influencing it. The assumption generally used in hydrological computations that the simultaneous vertical fluctuation in the groundwater table in different parts of mires are equal does not hold good in detail. Numerous cases were detected where the fluctuation at one place did not correspond to that at another site to a statistically significant degree. The main reason for the unequal fluctuation at the different sites seems to be the difference in the microtopography and in the hydraulic conductivity between the sites.
The PDF includes a summary in Finnish.
Altitude fluctuation of mire surface proportional to that of the groundwater table is presented for three virgin pine mires in Eastern Finland during the growing season 1982. The average amplitude of the surface fluctuation was found to be dependent on the period representing a certain type of weather, being limited to a certain maximum. The average amplitude of the surface fluctuation ranged from 18 to 45 mm; each of the mires followed a fluctuation scale of its own.
The daily fluctuation rates were low, generally 0.5–1 mm. No sudden fluctuation peaks occurred. Regularities in the surface fluctuation were caused by the duration of the period representing continuous sinking or rise of the groundwater table, and magnitude of it. The daily rate of the surface fluctuation related to that of the groundwater table was smaller in the beginning of such period than at the end of the same period. The one-directional rise or sinking of the altitude of the mire surface according to the groundwater table fluctuation is responsible for the autocorrelation of the long-term regression data.
The PDF includes a summary in Finnish.