The spectral absorptions of non-pigment particulate matter in Lake Kuileihu, Lake Donghu, Lake Liangzi and Lake Honghu were measured on 58 samples collected from September-October 2007 and October 2010. The goal was to develop exponential and power models which included the parameters of spectral slope (Sd) , inorganic suspended matter and wavelengths describing the spectral absorption of non-pigment particulate matter. The determination coefficient ( R2) , relative error ( RE) and root mean square error ( RMSE ) were used to assess the performance of the models. The average R2 value of the exponential model was 0. 998, which was higher than that of the power model (0.994) ( ANOVA, P <0. 001) . However, RE and RMSE for the exponential model (7. 01% and 0. 015 m-1, respectively) were lower than those for the power model (15.90% and 0.027 m-1, respectively) (ANOVA, P<0.001). These results indicated that the exponential model was better than the power model. The mean Sd value of non-pigment particulate matter from the exponential model was (12. 21 ± 1.08) μm-1, with a coefficient of variation of 8. 85% for the range of 400-700 nm. The Sd in Lake Kuileihu was slightly higher than those of the other three lakes, but without a significant difference. This suggests that a mean value could be used to model non-pigment paniculate matter spectral absorption in the four lakes. Significant linear correlations were found between non-pigment particulate matter absorption coefficient and inorganic suspended matter. The results indicate the potential to develop regional models to predict the absorption spectra using inorganic suspended matter concentration.%利用指数模型和幂函数模型对2007年和2010年长江中下游4个湖泊58个样本αd(λ)(非色素颗粒物吸收系数)光谱进行拟合,以R2(决定系数)、RE(相对误差)和RMSE(均方根误差)等统计参数判定模型效果.指数模型和幂函数模型R2平均值、RE、RMSE分别为0.998、7.01％、0.015 m-1和0.994、15.90％、0.027 m-1.统计检验显示,指数模型的R2显著大于幂函数模型(ANOVA,P＜0.001),而RE和RMSE则显著小于幂函数模型(ANOVA,P＜0.001).指数模型能更准确地拟合αd(λ),得到的Sd(光谱斜率)平均值为(12.21±1.08) μm-1,400～700 nm波段内变异系数为8.85％,空间上4个湖泊之间变化不是很明显,仅傀儡湖的Sd略低于其他3个湖泊.αd(λ)与ρ(ISM)(无机悬浮颗粒物浓度)呈极显著正相关,通过ρ(ISM)可以得到长江中下游典型浅水湖泊αd(λ)光谱模型.
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