| According to the in situ data of 32 sampling sites which were measured in June 2009, absorption, backscattering properties of different components and the spectral characteristics of diffuse attenuation coefficient （Kd） were analyzed in Chaohu Lake. And then the contribution of each factor’s affecting on Kd were calculated by Lee Model. Based on the analysis, the relationship between Kd and the affects were discussed. The result indicate that: the contribution to Kd of nonpigment suspended matter and chromophoric dissolved organic matter （CDOM） absorption presented an exponent decreasing trend with the increase of wavelength; from 400nm to 660nm, the contribution of phytoplankton absorption was stable, and for the phytoplankton strong absorption, the contribution had a peak value at 675nm, and then rapidly decreased, the contributions of phytoplankton absorption and nonpigment suspended matter absorption have a relationship of restricting each other; the contribution of water absorption which increased with wavelength was to be the leading contribution factor after 682nm; the contribution of suspended particle backscattering increased till 571nm, after that it decreased and sustained at the second leading factor. The analysis of diffuse attenuation coefficient and its’ affecting factors showed that the correlation between Kd and inorganic particulate matter has the best correlation, organic particles followed, and the worst was chlorophyll a. The relationship between Kd（532）and the concentration of pigment particles, non-pigment particle and aCDOM（440） was higher than Kd（440）, Kd（676） and Kd（735）. |
