@article{oai:niigata-u.repo.nii.ac.jp:00028097, author = {佐藤, 修 and 鈴木, 幸治 and 青木, 滋}, journal = {新潟大学積雪地域災害研究センター研究年報, 新潟大学積雪地域災害研究センター研究年報}, month = {Mar}, note = {Ground waters are sampled from observation wells bored to measure ground water levels in Nagaoka and its outskirts. The water samples are analized for major ions and tritium concentrations. The analysis indicates 4 main aquifers (I, II, Ⅲ, IV) in an investigation area. Age of ground water in the aquifer I estimated from tritium concentration is youngest and ages of other aquifers become older with depth. The ground water in aquifer Ⅲ is recharged from rainfalls containing a large amount of tritium supplied since 1952 by the detonation of thermonuclear devices explosion in the atmosphere. The aquifer Ⅱ from which water using for snow melt is mainly pumped up is recharged from upperstream and infiltration in eastern mountain foot and partly recharged from river water of the Shinano river.}, pages = {45--55}, title = {長岡地区地下水の流動状況の地球化学的研究}, volume = {12}, year = {1991} }