為了解台灣水庫水質與光學性質之特徵與分布，本研究於2005年9月至2006年7月期間，於曾文水庫、虎頭埤水庫及高屏溪出海口至外海進行一系列的量測與採樣，量測與分析項目包含葉綠素a(Chl-a)、懸浮固體物(SS)等水質參數及浮游植物 、無生命微粒 與有色溶解性有機物質(CDOM) 吸收係數等光學性質以及水面遙測反射光譜 。研究方法則基於海洋光學原理，探討水庫水質及光學性質之關係，並建立適於各研究地點的半經驗模式。
由於虎頭埤水庫為優養水體，分析而得的水質參數及光學性質都偏高，相對而言曾文水庫較低，高屏溪出海口至外海則更低。曾文水庫光學性質以浮游植物及無生命微粒之吸收比例皆較高，而CDOM之時間分布與浮游植物相似；虎頭埤水庫無生命微粒吸收比例相當高，且偶爾浮游植物會不尋常地大量升高。另外發現SS濃度過高時，會干擾 之量測，導致準確度降低。Chl-a與 為非線性相關，屬於乘冪函數之模式；SS濃度及濁度與 且與 皆為線性相關，屬於線性函數之模式。而由曾文水庫所導出的半經驗模式亦可套用於虎頭埤水庫，將能預測浮游植物吸收係數 的時空分布。
本研究更進一步應用經驗模式，處理福衛二號衛星拍攝曾文水庫之多光譜影像，目的在於取得福衛二號影像之水質分布圖。將 重新取樣以應用於福衛二號可見光範圍的三個波段，成為 ，並以逐步迴歸分析 與Chl-a、SS及濁度，得到的模式之判定係數R2分別為0.790、0.865及0.947。因此本研究的結果具有很大的潛力，能以遙測影像評估水質。

In order to understand the characteristic and distribution of water quality and optical properties of reservoirs in Taiwan, a series of field measurements were conducted at various sites from September 2005 to July 2006, including Tseng-Wen Reservoir, Hu-Tou-Pi Reservoir, the estuary of Kao-Ping River and the margin sea in vicinity. The measurement and analysis include (1) water quality parameters, such as the chlorophyll-a concentration (Chl-a) and suspended solid (SS) content, (2) optical properties, such as the absorption coefficient of phytoplankton , detritus and colored dissolved organic matter (CDOM) , and (3) the spectral values of above-surface remote sensing reflectance . Various approaches based on the theory of ocean optics are employed to derive the relationship between the water quality and optical properties of reservoir, resulting in a semi-empirical model that is particularly valid for those study sites.
Because Hu-Tou-Pi Reservoir is classified as the eutrophication status for most of the time, the parameters of water quality and optical properties all reach the highest values. By contrast, the parameters are lower in Tseng-Wen Reservoir and are much lower in the estuary of Kao-Ping River and the margin sea in vicinity. As to the optical properties, and in Tseng-Wen Reservoir are both high. The temporal distribution of is similar to the temporal distribution of . is even higher in Hu-Tou-Pi Reservoir and some unusual blooming of phytoplankton can be found occasionally in this area too. When SS is too high, the measurement of would be influenced, resulting in a lower accuracy. The non-linear relationship between Chl-a and is found to be a power function, while SS and turbidity are linearly correlated with or , respectively. The semi-empirical model derived in Tseng-Wen Reservoir can be applied to Hu-Tou-Pi Reservoir to estimate the temporal and spatial distributions of .
This research takes a further step to apply the semi-empirical model to process the multi-spectral images of Tseng-Wen Reservoir taken by FORMOSAT-2, with the intention to derive the map of water quality from FORMOSAT-2 imagery. The is resampled to three spectral bands in the visible range of FORMOSAT-2, namely . The approach of stepwise regression is then employed to relate with Chl-a, SS and turbidity. The results show that the coefficient of determination R2 all attain very high values of 0.790, 0.865 and 0.947 for Chl-a, SS and turbidity, respectively. Results from this research would have great potential in assessing the water quality from remote sensing imagery.

參考文獻
Bricaud, A., A. Morel and L. Prieur, 1981. Absorption by dissolved organic matter of the sea (yellow substance) in the UV and visible domains, Limnol. Oceanogr., 26, 43 – 53.
Bricaud, A. and D. Stramski, 1990. Spectral absorption coefficients of living phytoplankton and non-algal biogenous matter: A comparision between the Peru upwelling area and the Sargasso Sea. Limnol. Oceanogr., 35, 562 – 582.
Bricaud, A., M. Babin, A. Morel and H. Claustre, 1995. Variability in the chlorophyll-specific absorption coefficients of natural phytoplankton: Analysis and parameterization. J. Geophys. Res., 100, 13321 – 13332.
Bricaud A., A. Morel, M. Babin, K. Allali and H. Claustre, 1998. Variations of light absorption by suspended particles with chlorophyll a concentration in oceanic (case 1) waters: Analysis and implications for bio-optical models. J. Geophys. Res., 103, 31033 – 31044.
Buiteveld, H., J. H. M. Hakvoort and M. Donze, 1994. The optical properties of pure water. in Ocean Optics XII, J. S. Jaffe, Editor, Proc. Soc. Photo-Opt. Instrum. Eng., 2258, 174 – 183.
Carder, K. L., S. K. Hawes and Z. P. Lee, 1994. SeaWiFS algorithm for chlorophyll a and colored dissolved organic matter in a subtropical environment. SeaWiFS working group report.
Gordon, H. R. and A. Y. Morel, 1983. Remote assessment of ocean colour for interpretation of satellite visible imagery. A review. New York: Springer.
Hojerslev, N. K. and I. Trabjerg, 1990. A new perspective for remote sensing of plankton pigments and water quality. Univ. Copenhagen, Inst. Phys. Oceanogr. Rep., 51, 10.
Iturriaga, R. and D. A. Siegel, 1989. Microphotometric characterization of phytoplankton and detrital absorption properties in the Sargasso Sea. Limnol. Oceanogr., 34, 1706 – 1726.
Jerlov, N. G., 1951. Optical Studies of Ocean Water. Report of Swedish Deep-Sea Expeditions, 3, 73 – 97.
Jerlov, N. G., 1976. Marine Optics, Elsevier, Amsterdam.
Kirk, J. T. O., 1980. Spectral absorption properties of natural waters: contribution of the soluble and particulate fractions to light absorption in some inland waters of southeastern Australia. Aust. J. Mar. Freshwater Res., 31, 287 – 296.
Kirk, J. T. O., 1983. Light and photosynthesis in aquatic ecosystems. Cambridge University, New York.
Kirk J. T. O., 1994. Light and photosynthesis in aquatic ecosystems (second edition). Cambridge University, New York.
Kishino, M., M. Takahashi, N. Okami and S. Ichimura, 1985. Estimation of the spectral absorption coefficients of phytoplankton in the sea. Bull. Mar. Sci., 37, 634 – 642.
Kou, L., D. Labrie and P. Chylek, 1993. Refractive indices of water and ice in the 0.65- to 2.5-μm spectral range. Appl. Optics, 32, 3531 – 3540.
Lee, Z. P., 1994. Visible-infrared remote-sensing model and applications for ocean waters, Ph.D. dissertation ~Department of Marine Science, University of South Florida, St. Petersburg, Fla.
Lee, Z. P., K. L. Carder, C. D. Mobley, R. G. Steward and J. S. Patch, 1198. Hyperspectral remote sensing for shallow waters. 1. A semianalytical model. Appl. Optics, 37, 6329 – 3338.
Mitchell, B.G. 1990. Algorithms for determining the absorption coefficient of aquatic particulates using the quantitative filter technique (QFT). Ocean Optics X, 137 – 148.
Mobley, C. D., 1994. Light and water：Radiative transfer in natural waters. Academic, San Diego.
Mobley, C. D., 1999. Estimation of the Remote-Sensing Reflectance from Above-Surface Measurements. Appl. Optics, 38, 7442 – 7455
Morel, A. and L. Prieur, 1977. Analysis of variations in ocean colour. Limnol. Oceanogr., 22, 709 – 722.
Morel, A., and A. Bricaud, 1981. Theoretical results concerning light absorption in a discrete medium, and application to specific absorption of phytoplankton. Deep-Sea Res. 28, 1375 – 393.
Morrow, J. H., W. S. Chamberlin and D. A. Kiefer, 1989. A two-component description of spectral absorption by marine particles. Limnol. Ocaenogr., 34, 1500 – 1509.
Mueller, J. L., G. S. Fargion and C. R. McClain,S. Pegau, J. R. V. Zaneveld, B. G. Mitchell, M. Kahru, J. Wieland and M. Stramska, 2002. Ocean Optics Protocols For Satellite Ocean Color Sensor Validation, Revision 4, Volume IV: Inherent Optical Properties: Instruments, Characterizations, Field Measurements and Data Analysis Protocols. NASA, Greenbelt, Maryland.
Mueller, J. L., G. S. Fargion, C. R. McClain, R.W. Austin, A. Morel, G.S. Fargion and C.R. McClain, 2003. Ocean Optics Protocols For Satellite Ocean Color Sensor Validation, Revision 4, Volume I: Introduction, Background and Conventions. NASA, Greenbelt, Maryland.
Pegau, W. S., and J. R. V. Zaneveld, 1993. Temperature dependant absorption of water in the red and near-infrared portions of the spectrum. Limnol. Oceanogr., 38, 188 – 192.
Pelevin, V. N. and V. A. Rutkovskaya, 1977. On the optical classification of ocean waters from the spectral attenuation of solar radiation. Oceanology, 17, 28 – 32.
Pope, R. M. and E. S. Fry, 1997. Absorption spectrum (380-700 nm) of pure water. II. Integrating measurements. Appl. Optics, 36, 8710 – 8723.
Prapas, E. E., M. E. Dunnigan and A. M. Trimbee, 1988. Comparison of in situ estimates of chlorophyll a obtained with Whateman GF/F and GF/C glass-fiber filters in mesotrophic to hypereutophic lakes. Can. J. Fish., Aquat. Sci., 45, 910 – 914.
Prieur, L. and S. Sathyentranath, 1981. An optical classification of coastal and oceanic waters based on the specific spectral absorption curves of phytoplankton pigments, dissolved organic matter and other particulate materials. Limnol. Oceanogr., 26, 671 – 689.
Roesler, C. S., M. J. Perry and K. L. Carder, 1989. Modeling in-situ phytoplankton absorption from total absorption spectra in productive inland marine waters. Limnol. Oceanogr., 34, 1510 – 1523.
Roesler, C.S., 1998. Theoretical and experimental approaches to improve the accuracy of particulate absorption coefficients derived from the quantitative filter technique. Limnol. Oceanogr., 43, 1649 – 1660.
Sathyendranath, S., L. Lazzara and L. Prieur, 1987. Variations in the spectral values of specific absorption of phytoplankton. Limnol. Oceanogr., 32, 403 – 415.
Sipelgas, L., H. Arst, K. Kallio and A. Erm, 2003. Optical properties of dissolved organic matter in Finnish and Estonian Lakes. Nordic Hydrology, 34, 361 – 386.
Smith, R. C. and K. S. Baker, 1978. Optical classification of natural waters. Limnol. Oceanogr., 23, 260 – 267.
Smith, R. C. and K. S. Baker, 1981. Optical properties of the clearest natural waters (200 – 800 nm). Appl. Optics, 20, 177 – 184.
Sogandares, F. M. and E. S. Fry, 1997. Absorption spectrum (340-640 nm) of pure water. I. Photothermal measurements. Appl. Optcs, 36, 8699 – 8709.
Tzortziou, M., 2004. Measurements and characterization of optical properties in the Chesapeake Bay’s estuarine waters using in-situ measurements, MODIS satellite observations, and radiative transfer modeling. Ph. D. University of Maryland, College Park.
Yacobi, Z. Y., J. J. Alberts, M. Takacs and M. McElvanine, 2003. Absorption spectroscopy of colored organic carbon in Georgia (USA) rivers: the impact of molecular size distribution. J. Limnol., 62, 41 – 46.
Zepp, R. G. and P. F. Schlotzhauer, 1981. Comparison of photochemical behavior of various humic substances in water: 3. Spectroscopic properties of humic substances. Chemosphere, 10, 479 – 486.