市街地河川における降雨時流出負荷量の変化特性

抄録

It is generally known that suspended matters or components differ from the dissolved in the relationship between their loadings and flow. We made clear that “n” in the expression of L= a·Qⁿ fairly dispersed with each rain event by the analysis of runoff loadings in an urban stream on twelve rain events for a half year.
The differences of both in the runoff characteristics was mainly depended upon the differences of their runoff behaviours in transit, especially, the temporary storage in river bed and watershed.This influence was comfirmed as the phenomena of high loadings for early stage of runoff and the fluctuation of “n”, that is, (ΔL/L) / (ΔQ/Q) in succession of runoff under one rain event.
The runoff of temporary storage also appeared in the variation of the relationship between cumulative loadings and cumulative flow under a rain event. This phenomena was caused by the differences of initial condition before the rain and runoff pattern, and gave the basis of introductin of temporary storage (S). However, on dissolved matters the sum of runoff loadings (∑L) is able to be estimated by the sum of flow (∑Q), that is, L=a· (∑Q) ⁿ.