Abstract
Ikeshima Coal Mine was closed in Nov e mber 29th,2001, after 42 years of operation. The pining area was in the southwest of the Ikeshima Island. The drainage increased as the min ing areas extended, creating problems in both production operation and safety. The waters of dr ainage Ind flood in the mine have characteristics that (1) the rate of drainage decreases, (2) the c hemical omponents of the water in the floods do not change much with time but (3) they differ locally. Ile results of the investigation show that (1) the drainages in this mine are classified into 3 types by the combination of dissolved ions, (2) water eruption decreases exponentially, and (3) the southwest area of Ikeshima Island, the western area of the main drifts, is estimated to have hu ge eater bearing areas.
