著者
鶴巻 道二 桜本 勇治
出版者
公益社団法人 日本地下水学会
雑誌
日本地下水学会会誌 (ISSN:00290602)
巻号頁・発行日
vol.27, no.1, pp.1-16, 1985-02-28 (Released:2012-12-11)
参考文献数
51
被引用文献数
4 2

The average abundance of fluorine in the earth's crust is rather plentiful than that of chlorine, but the average concentration of fluoride in natural water is very low as compared with chloride. Fluoride is well known to produce strong teeth mottled in children raised where the fluoride concentration of water supply is above the recommended limit. In Japan, the limited value for drinking water is settled for 0.8 mg/i. In other respects, the concentration of fluoride more than 2 mg/kg is adopted as one of the criterion for mineral water which discriminate between normal water and abnormal water. In this paper, five case studies, all from Kinki District, have been chosen to discuss how the high fluoride groundwater is formed.In the case of Rokko granitic area, south-eastern part of Hyogo Prefecture, the possible origin of fluoride in water is due to the presence of high fluorine biotite in the rocks. The Paleozoic sandstone and shale in the northern part of Osaka Prefecture, Hokusetsu area, frequently contain high fluorine through contact metamorphism. The wells drilled in these rocks yield high fluoride water. As for these cases, high fluoride water often accompanies with high pH. Some leaching experiments using granitic rocks result in a similar relation between fluoride concentration and pH. The fluoride ion can be bounded to mineral in place of hydroxyl ion, so that with increasing pH it can be displaced from this site by hydroxyl ion in solution.A few cases of high fluoride stratum waters are reported in this area. It is not clear that the waters are caused by the geological structure which permits the upward flow of groundwater in a basement rock, or by the presence of fluorine-bearing-minerals in the stratum. More detailed researches are required in the case of stratum water.
著者
安池 慎治 鈴木 裕一
出版者
公益社団法人 日本地下水学会
雑誌
日本地下水学会会誌 (ISSN:00290602)
巻号頁・発行日
vol.28, no.4, pp.163-171, 1986 (Released:2012-12-11)
参考文献数
12
被引用文献数
2

The Kanto Loam is a deposit of the volcanic ash, and is widely distributed in the Kanto district. The purpose of this paper is to clarify the effects of tube-like macropores on hydraulic conductivities and on its anisotropy of the Kanto Loam. The permeability tester developed for this study was used to measure the anisotropy of conductivities. By using this device, it is possible to obtain the conductivities of two directions (vertical and horizontal) in one sample, simultaneously. Undisturbed soil samples for this measurements were taken at the outcrop in Kawasaki city in every 1 meters height. As a result, the following conclusions are obtaind.1. The hydralic conductivities of the layer with many tube-like macropores is much larger than that of layer with few macropores. The magnitude of the difference is 10 times in horizontal direction and 100 times in vertical.2. The anisotropy of the hydraulic conductivity is also much influenced by the effects of tube-like macropores. Without tube-like macropores, the ratios of Kv (vertical hydraulic conductivity) to Kh (horizontal one) range from 1.0 to 1.5, while with macropores, the ratios of Kv to Kh range from 3.0 to 20.
著者
池田 喜代治
出版者
公益社団法人 日本地下水学会
雑誌
日本地下水学会会誌 (ISSN:00290602)
巻号頁・発行日
vol.24, no.2, pp.77-93, 1982-07-31 (Released:2012-12-11)
参考文献数
17
被引用文献数
1 1

The Southern foot area of Mt. Fuji, including its lower flank and the coastal plain to the south in Shizuoka Prefecture, is a suitable field to study the relationship between hydrogeology and chemical characters of ground water.Aquifers in the area are distributed in the volcanic strata from the volcanoes [Ko(Old)-Fuji, Fuji, and Ashitaka] and in the alluvial deposits. These aquifers are under a mineralogically uniform condition. Analytical data of natural ground water and leaching experiments on the rocks indicate that the ground water can be grouped by the water temperature, ratio of chemical constituents, bicarbonate (HCO3-) content, total dissolved solids, and others. The g -ound water borne at the depth of 150-250 m in coastal area has a matked discontinuity of HCO3- concentration, which is related with the geology.Chemical constituents in water of the volcanic layers seem to originate from processes of weathering of volcanic rocks. The constituents in water can be explained as a results of weathering reactions.
著者
菅野 敏夫 石井 武政 黒田 和男
出版者
公益社団法人 日本地下水学会
雑誌
日本地下水学会会誌 (ISSN:00290602)
巻号頁・発行日
vol.28, no.1, pp.25-32, 1986 (Released:2012-12-11)
参考文献数
11
被引用文献数
1 1

Water level of Lake Kawaguchi in Yamanashi Prefecture had risen more than 3 m above the standard level after the heavy rainfalls in summer of 1983. On that opportunity the authors started to study the hydrogeological conditions around the lake with the use of long-term observation data of the lake water level, groundwater level, precipitation and others (Figs.4 and 5).The area is composed mainly of the Tertiary Misaka Group and the Quaternary volcanic rocks extruded from Fuji Volcano (Fig.1). The Misaka Group and the Kofuji Mud-flow Deposits, one of the effusive rocks of the volcano, constitute the hydrogeological impermeable bed rocks.Although Lake Kawaguchi has no natural mouth for surface discharge, the water is drained off through the man-made tunnels. On the other hand, it is likely that the water permeates through the volcanic rocks into the underground valley about 5 km south of the lake, judging from the contour line of the groundwater level (Fig.2). Figures 2 and 3 indicate that the hydrogeological watershed of the lake occupies only the northern part of the topographic watershed which extends southwards to the top of Mt. Fuji.The lake water is recharged from the surrounding mountains of the Misaka Group. The lake water remarkably rises after the 3 days rainfall reaches more than 200 mm (Figs.6 and 7). When the 3 days rainfall is less than 100 mm, it is invisible. Fluctuations of the lake water coincide with the rainfall pattern (Fig.4). The graph of the accumulation value of the rainfall variation is similar to the fluctuation of the lake water level.