Ultra-wind Induced Matter-transfer Between Sediments And Overlying Water In Lakes

When the release of sediment became a more and more important internationalproblem, the research of nutrients transform mechanism in lakes in ultra-wind(typhoon) is few. This paper selected sediment-water interface in lake Taihu as themain research object, simulating the effects induced by Kanu typhoon tosediment-water interface in typical area of Lake Taihu indoors by sedimentresuspension equipment, is mainly to uncover the change state of nutrients in thewater body in ultra-wind (typhoon), provides scientific basis for the research ofsediment burdens in lakes and precise manipulate parameters for hydraulicsimulation equipments. The main research results of this paper are below:1．During the ultra-wind (typhoon), average wind disturb depth of the sedimentis in millimeter, the loading of SS is 13．3×10⁹ kilogram, which is 23 times of staticloading.2．The concentration of NH₄⁺-N in Meiliangwan area and Dapukou areadecreased during the typhoon, but the concentration of DTN increased, whichindicates the NH₄⁺-N transfer to NO₂^--N, thus the concentration of NH₄⁺-N inthe water body decreased.3．During the typhoon, the concentration of PO₄^3--P increased, theconcentration of DTP increased little, which indicates the release of phosphorus fromthe sediment.4．After the typhoon, TP in the surface layer of the sediment decreased, butlabile phosphorus, iron bounded phosphorus, aluminum bounded phosphorus,organic phosphorus increased.5．The numerical results of nutrients under static state and typhoon state inTaihu Lake indicate: during the typhoon, PO₄^3- in the water body increases from57．6×10³ kilogram (static loadind) to 66．8×10³ kilogram, NH₄⁺in the water bodydecreases from 741．9×10³ kilogram (static loadind) to 438．5×10³ kilogram.