Department of Earth Science, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, SL118, Indianapolis, IN 46202, USA.
Sci Total Environ. 2012 Oct 1;435-436:141-50. doi: 10.1016/j.scitotenv.2012.07.023. Epub 2012 Jul 31.
Phycocyanin (PC) is the unique and important accessory pigment for monitoring toxic cyanobacteria in inland waters. In this study, a semi-analytical algorithm combining both three band indices and a baseline algorithm (TBBA) was developed to estimate PC concentrations and then tested in three eutrophic and turbid reservoirs. TBBA does not need to optimize wavelengths as either the traditional baseline algorithm or three-band algorithms does when it is used across different study sites. TBBA evidently corrects some effects of absorptions due to colored detritus matter and other pigments and backscattering of water column. TBBA accurately estimated PC concentrations with R(2)=0.8573 and rRMSE=31.4% for water samples with the PC range from 1.4 mgm(-3) to 146.1 mgm(-3). Particularly, TBBA outperformed three-band algorithms and a previously proposed semi-empirical algorithm for the prediction of low PC (PC ≤ 50 mgm(-3)) concentration. Further analysis reveals that both the variations of PC:Chl-a and PC:TSM are important factors influencing the performance of all PC algorithms examined in this study and more efforts are required to improve the performance of TBBA on water samples with low PC concentration.
藻蓝蛋白（PC）是监测内陆水域有毒蓝藻的独特且重要的辅助色素。在这项研究中，开发了一种半分析算法，该算法结合了三波段指数和基线算法（TBBA），用于估计 PC 浓度，然后在三个富营养化和混浊的水库中进行了测试。TBBA 不需要像传统的基线算法或三波段算法那样在不同的研究地点进行优化波长。TBBA 明显纠正了由于有色碎屑物质和其他色素以及水柱后向散射引起的吸收的一些影响。TBBA 准确地估计了 PC 浓度，R(2)=0.8573，rRMSE=31.4%，用于 PC 范围为 1.4 mgm(-3)至 146.1 mgm(-3)的水样。特别是，TBBA 在预测低 PC（PC ≤ 50 mgm(-3)）浓度方面优于三波段算法和以前提出的半经验算法。进一步的分析表明，PC:Chl-a 和 PC:TSM 的变化是影响本研究中所有 PC 算法性能的重要因素，需要进一步努力提高 TBBA 在低 PC 浓度水样上的性能。
