Abstract
Runoff rate of pollutant load (COD, N, P) was studied, as a planning parameter for water quality control of lakes or of inner sea areas. With three primary or secondary rivers, Ibo R., Kako R. and Kotoh R., daily sampling surveys more than one year, were practiced. Also, the discharge load in the river basins was calculated in detail. It was confirmed that the runoff rate of pollutant load had better be divided into two stages in convenience, i. e., flow-out and flow-down stage. Good accordance was observed between measured and calculated values of runoff load of pollutant, by setting the former value of flow-out rate 0.7-1.0, the latter value of flow-down rate as an expornential formula of flow-down distance. The application of this method to another several rivers was also satisfiable.
