HR: 0800h
AN: H41D-0450    [Abstracts]
TI: Natural hazards in urban area due to the change of groundwater environment -an example from Tokyo Metropolitan Area-
AU: * Tokunaga, T
EM: tokunaga@k.u-tokyo.ac.jp
AF: Institute of Environmental Studies, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan
AB: Tokyo, the capital of Japan, is situated in the southwestern part of the Kanto plain, the largest flat plain in Japan. The underground environments at the Tokyo Metropolitan Area have been changing dramatically in accordance with the change of groundwater condition and with the continuous increase and heavy usage of underground space. Because of the complex interaction between the change of groundwater environments and human activities for the underground usage, we have experienced a variety of human-induced natural hazards. In this presentation, the temporal change of groundwater environments and associated hazards at the Tokyo Metropolitan Area are described. Here, it is possible to divide the change into three stages, i.e., deterioration of underground and surface environments due to over exploitation of groundwater (first stage), regulation of groundwater extraction to the absolute minimum and the recovery of groundwater potentials (second stage), and damaging underground infrastructures by buoyant force and increase of groundwater seepage due to the recovery of groundwater potentials (third stage). Recent activities to use excess groundwater to improve the urban environments and to reduce the damage to underground infrastructures were shown. These activities should be expanded to achieve the sustainable development of the urban cities.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1829 Groundwater hydrology
DE: 1834 Human impacts
SC: Hydrology [H]
MN: Fall Meeting 2005