CHARACTERISTICS OF THE RUNOFF DISCHARGES AND GROUNDWATER LEVEL AT THE TASHIRO RAISED BOG IN JAPAN

摘要

Recently, water environment condition in peatland has become a serious problem in Japanese rural areas. The primary threats to water environment in peatland are change groundwater caused by reclamation of paddy field and grassland. Therefore it is necessary to design water management and plant protection for sustainability of conservation of peat land in Japan. In this paper, the water environment conditions were studied at the Tashiro raised bog in Aomori prefecture in the northern part of Japan. The rainfall, runoff discharge, groundwater level and hydraulic conductivity were measured. Clearly high groundwater level at the carpets of Sphagnum plants and low groundwater level at the water collecting in bottom of ditch were observed. The runoff discharge from the catchments area increased with rainfall during July and September and after the snow thaw in April. The runoff discharges and ground water level in the raised bog were greatly influenced by rainfall intensity. The outflow rate of runoff discharge from the catchments in the raised bog area was calculated.