降下煤塵量と降水量の間の関係について(V)

Abstract

In the first half of the present report, we have reviewed our calculation performed aiming at the collection efficiency (ε) of a rain-drop for a dust-particle and further, the amount (K) of air-suspended dust, a portion of which might be scavenged by rain-fall; in the course of calculation, we employed an approximation-including equation (denoted by (4) in text) and utilized the data of dust-fall and rain-water quantity obtained through a deposit-gauge net-work. In the latter half, we have derived a straightforward, or approximation-not-including equation (denoted by (5) in text) and have applied it to a number of instances; explicit as the equation is, it is rather involved from the point of practical use. The results of the calculation made by dint of the two equations (4) and (5) are shown in Table 4. The summary of the findings is as follows : With regard to the magnitudes of ε and K, they are each almost the same independently of the equation employed, ε being of the order of (10)^<-2> and K being as large as 3～4t/(km)^2・mo. There is, however, seen a clear difference between the two equations so far as the number of the instances to which the calculation proved applicable is concerned, equation (5) definitely surpassing equation (4).