Abstract:

 On the basis of qualitative analysis of the factors influencing the aquatic chemical composition of Xihu Lake,the equilibrium equation for chemical weathering is employed to quantitatively evaluate these factors. The results show that atmospheric precipitation,chemical weathering and oceanic material all contribute to the chemical composition of Xihu Lake. Ca and Mg come from the chemical weathering of minerals,especially of silicate while Na and K are controlled mainly by oceanic material. The less contribution of silicate weathering to the chemical composition of Xihu Lake demonstrates that chemical weathering is at the stage of decationizing.