scholarly journals Hydrogeology of the groundwater in crystalline schist landslides in Shikoku, Japan

2018 ◽  
Vol 55 (4) ◽  
pp. 153-162
Author(s):  
Hiromasa HIURA ◽  
Akira SUEMINE ◽  
Hiroyuki MAEDA ◽  
Gonghui WANG ◽  
Gen FURUYA
Keyword(s):  
2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Roxanne Lai ◽  
Takashi Oguchi

<p><strong>Abstract.</strong> Changing land use is an increasingly important issue as human habits, behaviors, and needs change. There has been an increase in land and agricultural abandonment in some places of the world. In Japan, movement of the population from rural to urban areas have resulted in much land and agricultural abandonment. In 2016, a land ministry survey showed that 4.1 million hectares of land in Japan had unclear ownership, with farmland making up 16.9% of the total. As vegetation cover changes after land abandonment, this temporal and spatial effect may have important effects on geomorphic processes such as landslide susceptibility and landslide kinematics.</p><p>Here we track long-term land use changes over vegetated landslide areas of the Sanbagawa and Mikabu Belts of Shikoku Island, Japan. The Sanbagawa and Mikabu Belts are metamorphic belts that run across Southwest Japan, and are home to numerous large crystalline schist landslides, including the widely-studied slow but continuously moving Zentoku landslide. Villages and communities have been built on these landslide areas due to historical and cultural factors, as well as the fertility of the soil. Consequently, given the changing land uses including land abandonment in these landslide areas over time, we use long-term high-resolution land cover vegetation datasets to examine first the long-term land use changes, and then use statistical methods to explore their relationships with landslide susceptibility and kinematics. Mapping of spatial data and their analysis using GIS constitute a core part of the research. The results suggest interconnections between land use changes and land movement.</p>


2007 ◽  
Vol 48 (2) ◽  
pp. 80-89 ◽  
Author(s):  
Eiji TAMURA ◽  
Akira JYONAI ◽  
Shin-ichi MATSUZAKI ◽  
Syuichi HASEGAWA

1977 ◽  
Vol 83 (4) ◽  
pp. 243-243 ◽  
Author(s):  
Isamu NAKAYAMA ◽  
Sho TAKANO ◽  
Tsunemasa SHIKI
Keyword(s):  

Landslides ◽  
1997 ◽  
Vol 34 (2) ◽  
pp. 9-16_1 ◽  
Author(s):  
Gen FURUYA ◽  
Kyoji SASSA ◽  
Hiroshi FUKUOKA ◽  
Hiromasa HIURA

1970 ◽  
Vol 7 (6) ◽  
pp. 1383-1401 ◽  
Author(s):  
K. Shibata ◽  
T. Nozawa ◽  
R. K. Wanless

Rb–Sr whole-rock and mineral isochron ages have been determined for metamorphic and granitic rocks of the Hida metamorphic belt. The results indicate that an extensive metamorphic event together with plutonic activity took place within the belt during the latest Paleozoic – early Mesozoic period. The older ages of 220–250 m.y. represent an earlier phase of the metamorphism, whereas the younger ages of 170–180 m.y. represent a later phase. The Funatsu granitic rocks yielded a whole-rock isochron age of 176 m.y. with an initial 87Sr/86Sr ratio of 0.7056. This age is believed to indicate the time of original emplacement, and the rocks are considered to represent late-kinematic intrusion in the Hida belt.Some information on the middle Paleozoic metamorphism in the Hida Mountains was obtained from the isochron study. The whole-rock isochron age of 412 m.y. for the metamorphic rocks of the Fujibashi area may be considered, although not confirmed, to indicate the time of older metamorphism. The Omi Schist of the Circum–Hida crystalline schist belt, which belongs to the glaucophanitic type of metamorphism, gave a mineral isochron age of 350 m.y. thereby providing evidence of mid-Paleozoic metamorphism.The initial 87Sr/88Sr ratios for the whole-rock samples of the Hida metamorphic belt are found to be generally low, i.e. 0.705–0.708. This is especially so for the metamorphic rocks from the northern part of the belt where the lowest values were found.


1883 ◽  
Vol 10 (11) ◽  
pp. 507-511
Author(s):  
T. G. Bonney

A few years since it would have been flat heresy to assert that very clear proof would be necessary before we could accept a crystalline schist as the metamorphosed representative of a rock of Palæozoic age. Yet at the present time many who have made a special study of this branch of petrology would not hesitate to go thus far, and some would even declare that we do not know of any completely metamorphic rock which is not of Archæan age. Certainly the stock instances of metamorphism in Wales, and especially in Anglesey, in Cornwall, in Leicestershire, in Worcestershire, have utterly broken down on careful study. Outside the English Geological Survey probably no person who can use a microscope believes that the schists of Anglesey are altered Cambrian, or that the slates of this age are melted down into the quartz-porphyry of Llyn Padarn. It is becoming evident that even the metamorphic fastnesses of the Highlands are in danger, and that at any rate even there the realm of “altered Lower Silurian” will be grievously curtailed. Startling facts are now and then adduced by the defenders of what we may call the ‘established’ (i.e. non-progressive) geology; fossils are said to have occurred in crystalline non-calcareous rocks, Calamites in gneiss, Trilobites in mica-schist, and so on; but those who are familiar with the molecular changes which take place in the formation of such rocks as these will require the clearest evidence before they can accept statements so antecedently improbable.


2004 ◽  
Vol 40 (6) ◽  
pp. 472-483 ◽  
Author(s):  
Gen FURUYA ◽  
Akira SUEMINE ◽  
Hiromasa HIURA ◽  
Hiroshi FUKUOKA ◽  
Kyoji SASSA ◽  
...  

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