Nineteen fifty-eight was the year in which heavy investigations on groundwater resources for irrigation began. They have reached 31 in number up to date. The writers will citee three examples of theirs, i. e. a foot of a volcano, a tectonic basin and a limestone table-land.
(1) The eastern foot of Myôkô volcano
The geology consists of such strata as are shown below:
Drillings and pumping tests were carried out to each of three parts. The conclusions are below mentioned:
(A) Groundwater of an aquifer (a) is unconfined; that of (b) is confined.
(B) Aquifers (a) and (b) have a high permeability, while (c) has a low one.
(2) Fukushima tectonic basin
There are so thick quarternary deposits in this basin that their lower limit reaches 150m below the ground level; they are rich in growndwater resources.
Topographically, five plains can be seen-Anyôji, Iizuka, Yanome and Sakino plains and a flood one in descending order. The quarternary system is mainly fluvial deposit, and it looks partly lacustrine one. Various kinds of data show rather slow tectonic sinking and deposition.
According to electric prospectings, four subterranean valleys are presumed; the western deposit is rich in gravel, and the eastern one varies muder near Fukushima city.