Abstract
Subsidence of the ground is conspicuous in th lowlands of Kawaguchi and in southern part of Saitama Prefecture, causing various kinds of damages. In general, the ground subsidence occur where the humus soil is thick, such as a back marsh. And, the cumulative amount of subsidence is larger when the alluvial deposits are thicker. It is reported that the diluvial deposits are also subsiding lately, although it is questionable.
The ground subsidence is chiefly ascribed to the excessive utilization of underground water. Heavy traffic of these days may also account for the subsidence, but it is merely a superficial phenomenon. In order to prevent the ground subsidence, pumping of underground water must be carried out on a well-laid plan.
