3.1. 実験的に作った各種の有機, 無機の粒体けん濁液の濃度, ならびに粒径に対する透視度, 濁度の数量的な相互関係を検討し, これらの測定値からSSの概量を推定する式を導びき, 併せて, これらの関係を透明度を加えた諏訪湖の自然で観察した実例に適用した.
3.2. 透視度, 濁度, 透明度の相互間にはSSの有機無機の区別なく次の関係式が成立する.
Y=aX^b
X Y
SS量 濁度, 透視度 透明度 a>0 b<0
濁度 透明度a>0 b<0
透視度 透明度a>0 b<0
これらの諸関係は相関性が大きく, 各項の関係式が成立する条件が満される場合は, Yの値からXを推定することができる.
3.3. 透視度 (Y) とSS量 (X) の関係式において, 粒径大なれば光の透過率も大きく, 絶対値bの値は小となり, 従って透視度は大となる.
3.4. 濁度 (Y=吸光度) とSS量 (X) の関係式Y=aXにおいて, 粒径大なればaは小となるため, 濁度は小となる.
3.4. 性状末知の濁水中のSSの概量を推定するには, 濁度法より透視度法がすぐれている.
3.5. 諏訪湖のSS量と透視度, 透明度との間には, 前記実験の場合と同様な双曲線関係が認められる.SS量が透視度では50～100ppm, 透明度では30～40ppmの範囲を越えて増加しても透視度, 透明度の減少はきわめてわずかである.

抄録全体を表示

The writer performed well-water analyses (Aug.-Sept., 1968) for thirty two wells in an area of about 130 km² occupied by the alluvial fan and delta on the left side of the Shô-gawa, flowing northward through the western part of Toyama Pref. and pouring into the Bay of Toyama, and describes in this paper the state of variation of components dissolved in the groundwater, changing aspect of its quality with flowage, and the method of its flowing velocity measurement by means of the arbitrary time determination of argon dissolved in it.
(1) The fostering source of the groundwater in this plain is the surface running water of the Shô-gawa that infiltrates into the ground near the fan apex, about 100m in altitude. This infiltrating water flows down near to the fan margin, about 30m in altitude, as free-surface groundwater, but from this place the groundwater is divided into two parts by an aquifuge that is gradually developing, at a depth of 20-25m below the surface, toward the deltaic area, and the upper of them becomes a free-surface groundwater, and the lower a piestic surface groundwater, both extending to the deltaic area. From the fan margin to the delta there extends an area of artesian wells.
(2) Temperature of the groundwater is 12.5-14.5°C, but that of the well-water in the lower course of the Oyabe-gawa is as high as 17-18.8°C.
(3) Almost all of the well-water is of the Ca (HCO₃)₂ type of quality, and the increase of dissolved components and the ion-exchange reaction between Ca²⁺, Mg²⁺, etc. in the groundwater and Na⁺in the sediments in the course of flowing are observed. Well-water in the lower course of the Oyabe-gawa show some effect of sea-water, with much dissolved components and an advanced state of reduction, while the other well-water has less dissolved components and maintains the state of oxidation. Thus, the latter case implies the presence of no plenty reducing substance in the sediments through which the groundwater is flowing, and its short-period passage.
(4) The writer discovered a method of estimating the flowing velocity of the groundwater by means of arbitrary time measurments of the dissolved argon in the well-water at several stations.
This method is briefly explained as faollows. The infiltrating position of the river-water, hydro-geologically detected, and the annual rariation of temperature of the river-water at that position are previously surveyed. Any well that is in the direction of the main subsurface flowing and belongs to the same aquifer and seems to be free from any other infiltrating water is selected through the examination of the well-water. From the amount of dissolved argon in it measured, the temperature of the river-water at the time of its infiltration is estimated. Then, that time is known from that temperature and the annual variation of the river-water temperature. From the time difference between the time of infiltration and the argon measurment, the flowing period of the groundwater from the infiltrating point to the observed well situation is obtained, and hence the flowing velocity (mts/day), the distance between them being known.
This method, however, postulates that the growndwater travels that distance within a year.
The mean flowing velocity in the course of about 15 km, from the fan apex (altitude of about 100m) to the delta (altitude of about 10m), obtained by this method is 45-60mts/day.

抄録全体を表示

中国山脈における淡水棲三岐腸類の分布を調査し, 既報のデータを含めて当地方全域の分布地理を考察した。中国地方にはナミウズムシDugesia joponica ICHIKAWA etKAWAKATSUとミヤマウズムシPhagocata vivida (IJIMA et KABURAKI) の2種が広く分布している.D.japonicaは海岸線から標高1000～1 (4160m附近まで分布している (棲息水温範囲10.2～16.5℃).Ph.vividaは, 山陰地方では標高500～1450mの地域に広く分布し, それ以下の地域でも湧泉や湧泉流に出現する.山陽地方では, 本種の分布下限は標高ほぼ1000mの線である. 両種の示す垂直分布型はJ-JV-Vである.

抄録全体を表示