In this paper the features of grain size distributions are shown on the Senzu, the Kuze, the Nateuse and the Odomari reservoirs described in the 1st and 2nd Reports.
The Wentworth's grade scale of grain size and the Shepard's nomenclature based on the sand-silt-clay ratios being used, the sediments are found to range in the sandy-silty-clayey materials from upstream to downstream in reservoirs. The Krum-bein's Phi scale of grain size and the Inman's descriptive parameters being used, the Phi median diameter has the wide range of 1.0-8.5 with the tendency to increase from upstream to downstream in reservoirs, but the sorting has little variation range which centers 1.50 in the Phi deviation measure in the Senzu and Kuze reservoirs, or the complicated distribution with the range from very well sorted to poorly sorted degree in the Nat suse and Odomari reservoirs. In the Senzu reservoir, Sand is deposited in the topset bed, Silty Sand and Sandy Silt in the foreset bed, and Siilt n the bottomset bed of the delta.
It is found, that silty and clayey sediments corresponding to suspension load described by Harrison spread over the whole bottom, whereas sandy sediments corresponding to traction load are deposited from the river mouth to the dam in reservoirs.

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In this paper the writer studied the annual temperature change of impounded water at the Miura reservoir, Nagano prefecture, for purpose of power generation.
Though the change of impounded water in a natural lake had been precisely studied by late Dr. S. Yoshimura, the change ofimpounded water at an artificial reservoir has not been clear. So, he first intended to study a correspondence about an annual temperature change of water between a natural lake and an artificial reservoir.
The limnological appreciation is thought to be as follows. Al though a reservoir gives rise to a larger fluctuation of a water surface, its annual change of impounded water shows a considerable correspondence with that of a natural lake. That is to say, in summer the temperature gradient toward the bottom becomes a direct stratification and in winter it turns to a inverse stratification.
The obvious difference in comparison with a case of a natural lake is found out by a thin or lacking of a epilimnion, whai chscuorvofeafrc se water and shows a higher temperature, and temperature of deep part of reservoir is always higher than 40C in summer. The another difference is the fact in winter that cold water showing about 1.2deg;C goes down to a deep part.

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The writer represents the correlation about the geological stratum with the seismic velocity which has been observed on the piedmonts of volcanoes, Aso, Daisen and Fuji.
Analysing the reoults, he quantified the geological stratum with the seismic velocity on the piedmonts of volcanoes in japan.

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In May and June of 1964, on the northern foot of Mt. Asama where the Agatsuma Pyroclastic Flow covers the land surface, an electrical prospecting method was the put into practice by the author for the purpose of a survey on the ground water. His survey resulted.in recognizing the seasonal variation of the ρ-α curves and the surface Kotaki Pyroclastic Flow which is the previous land surface before the deposition of the Agatsuma Pyroclastic Flaw.
According to the ρ-α curvel the seasonal variations of the specific resistance of the Agatsuma and Kotaki Pyroclastic Flows are as follows:
(Agat Pyroclastic Flow)
In tile winter season 100×10⁴-200×10⁴ Ωcm
In the spring season 50×10⁴-150×10⁴ Ωcm
(Kotaki Pyroclastic Flow)
In the winter season 30×10⁴-150×10⁴ Ωcm
In the spring season 30×10⁴ - 70×10⁴ Ωcm

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Researching into the relations of the intensity against the external agencies of microscopic scales-rill erosions, frost erosions, etc.-with the own textures of the volcanic ash deposits, the author reached a conclusion as follows:
(The intensity of the volcanic ash deposits were considered according to the values measured with a pocket penetrometer.)
1) On the intensities (or penetration resistances) of the volcanic aSh deposits, the homogeneous ones are more intense than the granular ones.
2) On their specific resistances, the measured values of the homogeneousones are higher than the granular ones.
3) After the facts reduced from 1) and 2), where the horizons of volcanic ash deposits with granular textures are exposed just on the earth surface, the earth erosions advance rapidly and a great mass of volcanic ashes loses and removes.

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