余呉湖・湖沼堆積物解析から推定される後期完新世の湖沼 : 流域系水文環境変動

概要

論文の詳細を見る
Hydro-environmental fluctuations in the central Japan during the Late Holocene have been imprinted in the sediment cores from Lake Yogo, where hydrological conditions changed at c.700 AD; from low water regime to high water regime. An abrupt change in ^<210>Pb concentration of the cores shows that rapid increase in the sedimentation rate may have been connected to artificial channel construction in 1960. Temporal fluctuation in mineral particle size of sediment corresponds to yearly averaged precipitation observed near the lake before the construction (1896-1960), leading to that an annual precipitation around Lake Yogo in the Little Ice Age may be estimated about 2,200 mm and in the late part of Medieval Warm Episode about 2,500 mm, larger than during the past 30 years (about 2,000 mm).
日本地形学連合の論文
2002-07-25