Analysis of the Water Quality of the Initial Rainwater Collected from the Roof

Abstract

Rainwater collected from the roof surface is expected to vary greatly in quality depending on the surrounding environment of the building, floor height, and roof-surface material. Therefore, it is necessary to determine the quality of the collected. The quality of rainwater related to meteorology is not the same as that after collection, and thus the information cannot be used directly. Therefore, the measurement was conducted on the tin roof of the house at the water collection site. The results show that the amount of precipitation of about 1 mm is enough to exclude the initial precipitation. It is considered that the water quality item, which is an index of precipitation and electrical conductivity, is the most easy to measure and　install.