Estimation of vertical water and heat fluxes in the semi-confined aquifers in tokyo metropolitan area, japan

Autor: Isamu Kayane, S. Dapaah‐Siakwan
Rok vydání: 1995
Předmět:
Zdroj: Hydrological Processes. 9:143-160
ISSN: 1099-1085
0885-6087
DOI: 10.1002/hyp.3360090203
Popis: Groundwater circulation is known to be one of the agents responsible for the redistribution of geothermal energy by acting as a source or sink in the course of its movement through porous media. Heat transport in groundwater systems is considered to be a coupled process and the theory based on this was used to analyse temperature profiles of 30 thermally stable observation wells in a deep, semi-confined aquifer system in the Tokyo Metropolitan area. Vertical water fluxes in the semi-confined aquifers and the associated upward heat fluxes were estimated from a heat flux equation that describes convection and conduction processes of heat transport in one dimension. The vertical downward water fluxes in Shitamachi lowland, Musashino and Tachikawa terraces were 0.69-26.91 × 10 −9 , 1.46-70.92 × 10 −9 and 2.61-2204 × 10 −9 m/s, respectively. A vertical upward water flux of 1.80-33.60 × 10 −9 m/s was estimated in Shitamachi lowland. The water flux generally decreased with increasing depth for observation wells which intercepted more than one semi-confining layer. The estimated upward heat fluxes for Shitamachi lowland, Musashino and Tachikawa terraces were 0.32-1.12, 0.49-1.21 and 1.00-11.62 W/m 2 , respectively. The heat flux was highest in Tachikawa terrace where a major fault, the Tachikawa fault, is located. Generally, the estimated heat flux was higher in the semi-confining layers than in the aquifers. Areas with heat sources and sinks as well as groundwater flow patterns in the semi-confined aquifers were revealed by heat flux and temperature distributions in the study area
Databáze: OpenAIRE