東京低地における都市化に伴う浅層地下水環境の変化と地盤液状化リスク

概要

論文の詳細を見る
Data of shallow unconfined groundwater levels were collected from several previous studies and were compiled to understand the quantitative change of shallow groundwater environment with urbanization in the Tokyo lowland that isthe urban center of the Tokyo Metropolitan Area, Japan. Also, risk of soil liquefaction in this area that was evaluated by the Institute of Civil Engineering, Tokyo Metropolitan Government (ICE, TMG) at 1987 was mentioned from the viewpoint of change of shallow unconfined groundwater level.<BR>In the central part of the lowland, shallow unconfined groundwater level was considered to be slightly changed from the 1920s to the 1980s. However, sources of shallow unconfined groundwater were drastically changed. Although main source of shallow unconfined groundwater was leakage from water mains from the 1950s to the 1990s, the main source was infiltrated precipitation in present. This change was caused by the decreasing of rate of the leakage (only 3.6% in 2006). On the other hand, groundwater table in the area that land subsidence was induced by extensive confined groundwater exploitation and the elevation became lower than sea level was distributed beneath the ground surface thorough this period. That is, shallow unconfined groundwater discharged to the sewerage system in this area.<BR>From the results of comparison of groundwater levels between the previous studies, groundwater table map that was used for evaluation of the risk of soil liquefaction was considered to not have enough accuracy in local scale. Therefore, it is essential to understand the distribution of present groundwater table for improvement of the evaluation of soil liquefaction. Also, monitoring of groundwater levels is necessary to evaluate future change of shallow groundwater environment caused not only by human activities but also sea level rise induced by global warming.
日本水文科学会の論文

東京低地における都市化に伴う浅層地下水環境の変化と地盤液状化リスク

スポンサーリンク

概要

日本水文科学会 | 論文

スポンサーリンク