Episode Studies on Catchments Chemistry at Tie Shan Ping,Chongqing

摘要

The Tie Shan Ping(TSP) catchments are acidified due to acid deposition.The highest concentrations of SO2-4,NO-3,Ca2+,Mg2+ Al3+ and H+ occur in soil water and the maximum of molar ratio Ali/(Ca+Mg) during the Episode Studies is 1.27 in the bottom soil water in May 2003.Fuzzy Cluster Analysis for compartmental water chemistry in catchments shows stream water(SW) originates from the soil water generally.During event rain there may be 'pulse' of high concentration of chemical species in the stream.Total organic carbon,organic bound aluminum,total phosphorus,total nitrogen,NO-3 in SW are controlled by quick(high) flow.SW at new dam at TSP is from quick flow largely,including overland flow during wet period.Al3+,SO2-4 and H+ in SW are controlled by base flow during dry period and SW at old dam at TSP is from the base flow,largely.There are "alkaline pulse" and "acid pulse" in stream water during the event rain.The former may be caused by overland flow over the litterfall and topsoil horizons,and the latter by "piston flow" from soil water in deeper soil horizon largely.