Assessing Confined Groundwater Flow in Mainly Alluvial Area of Tokyo and Saitama

Abstract

Groundwater flow in confined aquifers of mainly Tokyo-Saitama alluvial area was assessed by examining horizontal and cross-sectional hydraulic potential distribution, change in head, and taking areal pumping discharge into account. Existence of low-head zone near east and north-east of Saitama, and Chiba Tokatsu area were observed in the confined aquifers with more than 100-m depth, while high-head zones existed around the low-head region. The low-head in the area was the result of groundwater pumping and limited supply from nearby high water potential zone.

The pattern in groundwater head change in the deep confined aquifers from low-head area to Tokyo alluvial area has been classified into three groups: (a) with direct influence of pumping in low-head area, (b) with indirect influence of pumping in low-head area, and (c) with direct influence of local pumping. Pumping regulation has resulted to decreased pumping discharge and increase in groundwater head in all the observation wells.