Spatial characteristics of groundwater temperature in the Ishikari Lowland, Hokkaido, northern Japan: analytical and numerical applications |
| |
Authors: | J Dim Y Sakura H Fukami A Miyakoshi |
| |
Institution: | (1) Graduate School of Science and Technology, Chiba University, 1–33 Yayoi-Cho Inage-Ku Chiba-Shi 263-8522, Japan,;(2) Department of Earth Sciences, Chiba University, 1–33 Yayoi-Cho Inage-Ku Chiba-Shi 263-8522, Japan,;(3) Hokkaido Geological Survey, Kita 19 Nishi 12 Kita-Ku, Sapporo 060-0819, Japan, |
| |
Abstract: | In porous sediments of the Ishikari Lowland, there is a gradual increase in the background geothermal gradient from the Ishikari
River (3–4 °C 100 m–1) to the southwest highland area (10 °C 100 m–1). However, the geothermal gradient at shallow depths differs in detail from the background distribution. In spite of convective
heat-flow loss generally associated with groundwater flow, heat flow remains high (100 mW m–2) in the recharge area in the southwestern part of the Ishikari basin, which is part of an active geothermal field. In the
northeastern part of the lowland, heat flow locally reaches 140 mW m–2, probably due to upward water flow from the deep geothermal field. Between the two areas the heat flow is much lower. To
examine the role of hydraulic flow in the distortion of the isotherms in this area, thermal gradient vs. temperature analyses
were made, and they helped to define the major components of the groundwater-flow system of the region. Two-dimensional simulation
modeling aided in understanding not only the cause of horizontal heat-flow variations in this field but also the contrast
between thermal properties of shallow and deep groundwater reservoirs.
Electronic Publication |
| |
Keywords: | Geothermal gradient Heat flow Groundwater flow Simulation modeling |
本文献已被 SpringerLink 等数据库收录! |
|