抄録
In order to know the influences of the quantity of flow, the temperature of water, etc. upon the ascent of fish-way by Plecoglossus altivelis, the values of probability of accidental coincidence and of probabilily of actual coincidence between several pairs of cases were calculated from the records of the number of ascent for unit time and those of the quantity of flow, the tempera-ture, the transparency of water and the meteorological conditions at each o'clock in daytime. Namely to know, for example, the influence of temperature, between : -
I the case in which the number of ascent is larger than the mean and the case in which the temperature is higher than the mean;
II the case in which the number of ascent is smaller than the mean and the case in which the temperature is lower than the mean;
III the case in which the number of ascent is smaller than the mean and the case in which the temperature is higher than the mean;
IV the case in which the number of ascent is larger than the mean and the case in which the temperature is lower than the mean.
Fairly systematic influences of the quantity of flow, the temperature of water, etc. upon the ascent of fish-way by Plecoglossus altivelis are recognizable, when the probabilities of actual coincidences are compared with those of accidental ones.
