The modern Forel-Ule scale: a ‘do-it-yourself’ colour comparator for water monitoring

S. Novoa; M. R. Wernand; H. J. van der Woerd

doi:10.2971/jeos.2014.14025

Journal of the European Optical Society - Rapid publications, Vol 9 (2014)

The modern Forel-Ule scale: a ‘do-it-yourself’ colour comparator for water monitoring

S. Novoa, M. R. Wernand, H. J. van der Woerd

Abstract

The colour comparator Forel-Ule scale has been used to estimate the colour of natural waters since the 19th century, resulting in one of the longest oceanographic data series. This colour index has been proven by previous research to be related to water quality indicators such as chlorophyll and coloured dissolved organic material. The aim of this study was to develop an affordable, ‘Do-it-Yourself’ colour scale that matched the colours of the original Forel-Ule scale, to be used in water quality monitoring programs by citizens. This scale can be manufactured with high-quality lighting filters and a white frame, an improvement with respect to the materials employed to manufacture the original scale from the 19th century, which required the mixing of noxious chemicals. The colours of the new scale were matched to the original colours using instrumental and visual measurements carried out under controlled lighting conditions, following the standard measurement protocols for colour. Moreover, the colours of the scale are expressed in Munsell notations, a standard colour system already successfully used in water quality monitoring. With the creation of this Modern Forel-Ule scale, as a ‘Do-it-yourself’ kit, the authors foresee a possible use of the Forel-Ule number as a water quality index that could be estimated by means of participatory science and used by environmental agencies in monitoring programs.

Full Text: PDF

Citation Details

Cite this article

References

W. Ule, ”Die Bestimmung der Wasserfarbe in den Seen, Kleinere Mittheilungen,” Dr. A. Petermanns Mitth. aus Justus. Perthes Geogr. Anstalt 38(70)-(71) (1892).

G. E. Hutchinson, A treatise on limnology. Vol. I, Geography, physics, and chemistry (John Wiley & Sons, Haboken, 1957).

F. A. Forel, Le Léman, Monographie Limnologique II (Librairie de l’Université, Lausanne, 1904).

M. R. Wernand, H. J. Van Der Woerd, and W. W. C. Gieskes, ”Trends in Ocean Colour and Chlorophyll Concentration from 1889 to 2000, Worldwide,” PLOS One 8(6), (2013).

Y. Huot, M. Babin, F. Bruyant, C. Grob, M. S. Twardowski, and H. Claustre, ”Relationship between photosynthetic parameters and different proxies of phytoplankton biomass in the subtropical ocean,” Biogeosciences 4, 853–868 (2007).

IOCCG, ”Remote Sensing of Ocean Colour in Coastal, and Other Optically-Complex Waters,” in Reports of the International Ocean Colour Coordinating Group No. 3, S. Sathyendranath, ed., p. 144 (IOCCG, Darmouth, 2000).

J. T. O. Kirk, ”Optical water quality, what does it mean and how should we measure it?,” Water Pollut. Control 60, 194–197 (1988).

D. G. Smith, G. F. Croker, and K. McFarlane, ”Human perception of water appearance,” New Zeal. J. Mar. Fresh. 29(1), 29–43 (1995).

D. G. Smith, A. M. Cragg, and G. F. Croker, ”Water clarity criteria for bathing waters based on user perception,” J. Environ. Manage. 33(3), 285–299 (1991).

P. A. Del Giorgio, and R. H. Peters, ”Patterns in planktonic P:R ratios in lakes: Influence of lake trophy and dissolved organic carbon,” Limnol. Oceanogr. 39(4), 772–787 (1994).

D. L. Christensen, S. R. Carpenter, K. L. Cottingham, S. E. Knight, N. LeBouton, J. P. Schindler, D. E. Voichick, et al., ”Pelagic responses to changes in dissolved organic carbon following division of a seepage lake,” Limnol. Oceanogr. 41, 553–559 (1996).

B. Wissel, W. J. Boeing, and C. W. Ramcharan, ”Effects of water color on predation regimes and zooplankton assemblages in freshwater lakes,” Limnol. Oceanogr. 48(5), 1965–1976 (2003).

L. M. Juarez, K.-H. Holtschmit, J. J. Salmeron, and M. K. Smith, ”The effects of chemical and visual communication, space availability, and substratum color on growth of the juvenile freshwater prawn Macrobrachium rosenbergii (De Man),” J. Exp. Mar. Bio. Ecol. 110(3), 285–295 (1987).

A. Kullberg, ”Benthic macroinvertebrate community structure in 20 streams of varying pH and humic content,” Environ. Pollut. 78(1)-(3), 103–106 (1992).

T. A. Haines, V. T. Komov, V. E. Matey, and C. H. Jagoe, ”Perch mercury content is related to acidity and color of 26 Russian lakes,” Water Air Soil Poll. 85, 823–828 (1995).

A. Nilsson, and L. Håkanson, ”Relationships between mercury in lake water, water colour and mercury in fish,” Hydrobiologia 235/236, 675–683 (1992).

J. Bøgestrand, P. Kristensen, and B. Kronvang, ”Source apportionment of nitrogen and phosphorus inputs into the aquatic environment,” Report 7, 48 (European Environment Agency, Copenhagen, 2005).

D. R. J. Moore, P.-Y. Caux, ”Ambient Water Quality Criteria for Colour in British Columbia: Technical Appendix” Ministry of Environment. Water Quality Branch (1997). http://www.env.gov.bc.ca/wat/wq/BCguidelines/colour

W. Preisendorfer, ”Secchi disk science: Visual optics of natural waters,” Limnol. Oceanogr. 3, 909–926 (1986).

P. A. Secchi, ”Relazione delle esperienze fatte a bordo della pontificia pirocorvetta l’Immacolata concezione per determinare la trasparenza del mare,” Il Nuovo Cimento 20, 205–238 (1864).

I. D. Cuthbert, and P. a. Del Giorgio, ”Toward a standard method of measuring color in freshwater,” Limnol. Oceanogr. 37(6), 1319– 1326 (1992).

R. J. Davies-colley, Smith, D.G, D. J. Speed, and J. W. Nagels, ”Matching natural water colors to Munsell standards,” J. Am. Water Resour. As. 33(6), 1351–1361 (1997).

R. J. Davies-Colley, W. N. Vant, and D. G. Smith, Colour and Clarity of Natural waters (Ellis Horwood Limited, Chicheste, 1993).

T. Y. Crowell Company, The Science of Color (Optical Society of America, Washington D. C, 1966).

A. H. Munsell, ”A Pigment Color System and Notation,” Am. J. Psychol. 23, 236–244 (1912).

R. J. Davis-Colley, and D. Ballantine ”Suitability of NZ Rivers for contact recreation,” NIWA, National Institute of Water and Atmospheric Research, Report 133, 19 (2010).

Ministry for the Environment Manatu Mo Te Taiao, ”Guidelines for the Management of Water Colour and Clarity, No. 2,” p. 77 (1994).

S. Novoa, M. R. Wernand, and H. J. van der Woerd, ”The Forel- Ule scale revisited spectrally: preparation protocol, transmission measurements and chromaticity,” J. Europ. Opt. Soc. Rap. Public 8, 13057 (2013).

D. Lison, M. De Boeck, V. Verougstraete, and M. Kirsch-Volders, ”Update on the genotoxicity and carcinogenicity of cobalt compounds,” Occup. Environ. Med. 58(10), 619–625 (2001).

J. H. Jerome, R. P. Bukata, P. H. Whitfield, and N. Rousseau, ”Colours of natural waters: 1. Factors controlling the dominant wavelength,” Northwest Sci. 68, 43–52 (1994).

J. H. Jerome, R. P. Bukata, P. H. Whitfield, and N. Rousseau, ”Colours of natural waters: 2. Observations of spectral variations in British Columbia,” Northwest Sci. 68, 53–64 (1994).

R. S. Berns, ”Principles of color technology,” F. W. Billmeyer, and M. Saltzman, ed., 247 (John Wiley & Sons, Haboken, 2000).

D. Farnsworth, ”The Farnsworth-Munsell 100-Hue and Dichotomous Tests for Color Vision,” J. Opt. Soc. Am. 33, 568–574. (1943).

HunterLab, ”Equivalent White Light Sources and CIE Illuminants,” Appl. Notes 17(5), 1–5 (2008).

ASTM Standard E1164, ”Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation,” American Society for Testing and Materials (ASTM) International (2003).

ASTM Standard E179-12, ”Standard Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials,” American Society for Testing and Materials (ASTM) International (2012).

ASTM Standard E308, ”Standard Practice for Computing the Colors of Objects by Using the CIE System,” American Society for Testing and Materials (ASTM) International (2013).

G. Wyszecki, and W. S. Stiles, Colour Science: Concepts and Methods, Quantitative Data and Formulae (John Wiley & Sons, Haboken, 1982).

ASTM Standard D1535, ”Standard Method of Specifying Color by the Munsell System,” American Society for Testing and Materials (ASTM) International (2013).

W. N. McFarland, and F. W. Munz, ”Part II: The photic environment of clear tropical seas during the day,” Vision Res. 15(10), 1063– 1070 (1975).

J. L. Mueller, G. S. Fargion, C. R. Mcclain, J. L. Mueller, R. R. Bidigare, C. Trees, W. M. Balch, et al., ”NASA/TM-2003- Ocean Optics Protocols For Satellite Ocean Color Sensor Validation,” Revision 5, Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Protocols NASA (2003). http://oceancolor.gsfc.nasa.gov/

M. Wang, ”Effects of ocean surface reflectance variation with solar elevation on normalized water-leaving radiance,” Appl. Optics 45(17), 4122–4128 (2006).

R. J. Davies-Colley, W. N. Vant, and R. J. Wilcock, ”Lake water color: Comparison of direct observations with underwater spectral irradiance,” Water Resour. Bull. 24(1), 11–18 (1988).

S. Q. Duntley, R. W. Austin, W. H. Wilson, C. F. Edgerton, and S. E. Moran, Ocean Color Analysis (NTiS 7420, 1974).

R. C. Smith, and K. S. Baker, ”Optical classification of natural waters,” Visibility Laboratory. Scripps Institution of Oceanography. La Jolla, California., p. 20 (1977). http://misclab.umeoce.maine.edu/education/VisibilityLab/ reports/SIO_77-4.pdf

M. R. Wernand, Poseidon’s paintbox historical archives of ocean colour in global change (PhD Thesis, Utrecht University, 2010).