抄録
Water quality of River Ogawa of Sapporo, located in the northern island of Japan, was analyzed from the data taken every day (every week in winter) frow September, 1986 till August, 1988. R. Ogawa (catchment area: 11km
2, length: 7.0km, average flow<at sampling point>: about 0.8m
3) is flowing down the forest mountain, Mt. Muine (1461m). In this report, we focused the specific behaviors of nutrients during the snow melting period. Results are;
(1) The rate of water load during this season was about 60% of yearly discharge. The rate of nutrients loads was surpassed 60%.
(2) Most of nutrients of this period were scrubbed out from soil and some of them were eluted out from accumulated matters.
(3) Nitrogen flew out mainly in dissolved form (almost as nitrate) and phosphorus in particulate one.
(4) The mean water quality of this period was in meso-eutrophic condition.
(5) Run-off pattern of chemical components during this period which were arranged by L=C*Q=c*Q
n (L: chemical component load, C: concentration, Q: flow, c, n: constant) showed nearly the same tendency as one through the whole year. Concentrations of nutrients, except ammonium, became dense as the flow increased (n>1). Concentration of ammonium and ordinary inorganic components was stable or somewhat decreased.(n=1or<1)
