Taniguchi Makoto, Shimada Jun, Fukuda Yoichi, Yamano Makoto, Onodera Shin-ichi, Kaneko Shinji, Yoshikoshi Akihisa
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan.
Sci Total Environ. 2009 Apr 15;407(9):3153-64. doi: 10.1016/j.scitotenv.2008.06.064. Epub 2008 Sep 14.
Anthropogenic effects in both Osaka and Bangkok were evaluated to compare the relationships between subsurface environment and the development stage of both cities. Subsurface thermal anomalies due to heat island effects were found in both cities. The Surface Warming Index (SWI), the departure depth from the steady geothermal gradient, was used as an indicator of the heat island effect. SWI increases (deeper) with the magnitude of heat island effect and the elapsed time starting from the surface warming. Distributions of subsurface thermal anomalies due to the heat island effect agreed well with the distribution of changes in air temperature due to the same process, which is described by the distribution of population density in both Osaka and Bangkok. Different time lags between groundwater depression and subsidence in the two cities was found. This is attributed to differences in hydrogeologic characters, such as porosity and hydraulic conductivity. We find that differences in subsurface degradations in Osaka and Bangkok, including subsurface thermal anomalies, groundwater depression, and land subsidence, depends on the difference of the development stage of urbanization and hydrogeological characters.
评估了大阪和曼谷的人为影响，以比较两个城市的地下环境与发展阶段之间的关系。在这两个城市都发现了由热岛效应引起的地下热异常。地表变暖指数（SWI），即与稳定地温梯度的偏离深度，被用作热岛效应的指标。SWI随着热岛效应的强度以及从地表变暖开始所经过的时间而增加（变深）。由热岛效应引起的地下热异常分布与同一过程导致的气温变化分布非常吻合，这在大阪和曼谷都由人口密度分布来描述。发现两个城市的地下水水位下降和地面沉降之间存在不同的时间滞后。这归因于水文地质特征的差异，如孔隙率和水力传导率。我们发现，大阪和曼谷地下退化的差异，包括地下热异常、地下水水位下降和地面沉降，取决于城市化发展阶段和水文地质特征的差异。
