| 珠江口水体组分的吸收特性分析 |
| 摘要点击 4027 全文点击 2001 投稿时间：2014-05-12 修订日期：2014-07-15 |
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| 中文关键词 珠江口 吸收系数 颗粒物 浮游植物 CDOM |
| 英文关键词 the estuary of Zhujiang River absorption coefficient particles phytoplankton colored dissolved organic matter(CDOM) |
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| 中文摘要 |
| 水体组分吸收特性是水下光场和水面光谱的主要影响因子，对其进行研究有助于提高对水体光学特性的认识和水质参数的遥感反演. 基于2013年7月珠江口水体30个样本的实测数据，对珠江口水体总颗粒物、非藻类颗粒物、浮游藻类和CDOM的吸收特征进行了分析，结果表明：1总颗粒物吸收特征为非藻类颗粒物主导类型；2非藻类颗粒物的吸收系数遵循指数衰减规律，主要来源是陆源性输入，指数斜率Sd均值与空间变化幅度高于内陆二类水体；3多项式关系能较好地表达aph（440）与叶绿素a浓度的关系，而aph（675）与叶绿素a浓度存在很好的线性相关，辅助色素对浮游藻类吸收系数的影响主要在短波波段，长波波段叶绿素a的影响占主导地位，比吸收系数随叶绿素a浓度的增加而减小，呈现幂指数衰减规律；4CDOM输入以陆源为主，光谱曲线在紫外波段250~290 nm之间存在一个吸收肩，按光谱特征分段拟合Sg值能够更好地表达CDOM吸收特性，M值与A段（240~260 nm）的斜率Sg值呈现较强的正相关，珠江口水体的M值较小，CDOM中腐殖酸含量较高；5珠江口水体非色素颗粒物吸收在总吸收中占主导地位，浮游藻类吸收对总吸收的贡献远小于非色素颗粒物，CDOM吸收对总吸收的贡献最小，当CDOM中腐殖酸含量较高时，CDOM对水体总吸收的贡献大，腐殖酸含量较低时，CDOM对水体总吸收的贡献小. |
| 英文摘要 |
| Spectral absorption properties of the water constituents is the main factor affecting the light field under the surface of the water and the spectrum above the surface of the water. Thus, the study is useful for understanding of the water spectral property and the remote reversing of water quality parameters. Absorption properties of total suspended particles, non-algal particles, phytoplankton and CDOM were analyzed using the 30 samples collected in July 2013 in the estuary of Zhujiang River. The results indicated that: 1 the non-algal particles absorption dominated the absorption of the total suspended particles; 2 the absorption coefficient of the non-algal particles, which mainly came from the terrigenous deposits, decreased exponentially from short to long wavelength. In addition, the average value and spatial variation of the slope Sd were higher than those in inland case-Ⅱ waters; 3 the absorption coefficient of phytoplankton in 440nm showed a better polynomial relationship with chlorophyll a concentration, while the absorption coefficient of phytoplankton in 675 nm linearly related with the chlorophyll a concentration. Moreover, the influence of accessory pigments on phytoplankton absorption coefficient mainly existed in the range of short wavelength, and Chlorophyll a was the main influencing factor for phytoplankton absorption in long wavelength. The specific absorption coefficient of phytoplankton decreased the power exponentially with the increase of the chlorophyll a concentration; 4CDOM mainly came from the terrigenous sources and its spectral curve had an absorption shoulder between 250-290 nm. Thus, a piecewise Sg fitting function could effectively express CDOM absorption properties, i.e., M value and Sg value in period A (240-260 nm) showed a strong positive correlation. The M value was low, and the humic acid had a high proportion in CDOM; 5 the non-algal particles absorption dominated the total absorption in the estuary of Zhujiang River, and the contribution of the phytoplankton absorption to the total absorption was far lower than that of the non-algal particles. While the contribution of the CDOM was the lowest. The contribution of the CDOM absorption to the total absorption was relatively larger when the content of humic acid was higher. |
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