Abstract:

The water quality of rainfall, throughfall, stemflow and runoff in the headsteam of Ashi River was studied. The results showed: The acidification of stemflow was most obvious, the runoff had better buffering ability of water acidification; The content of COND, TDS, K and Mg increased in the throughfall and stemflow through the larch forest canopy; The content of Na in throughfall was lower than rainfall in July, August and September; The temporal variation of Zn was consistent in the throughfall, stemflow and runoff, that was the content of Zn decreased gradually from June to September; The monthly average contents of Mn and Fe in stemflow and runoff were higher than that in rainfall and throughfall; After running off through the soil, the content of TURB and TDS in the stream reduced obviously; The temporal variation of Mg and Zn was similar between in the brook and river, the content of Mg was the highest in June and the lowest in September, the content of Zn was the highest in June, and nothing was found in September and October; The content of total nitrogen, total phosphor，COND, TDS, Na, Mg and Ca in the river was higher than that in the brook every month; In general evaluation,the brook water quality belongs to class Ⅱ, while the river water quality to class Ⅳ.

Key words: rainfall, throughfall, stemflow, runoff, water quality