Photography in limnology: documentation of lake color using a CCD camera

Abstract

During a survey of Norwegian lakes, photographic records were made of lake color as reflected by a white Secchi disk positioned at half of the depth of extinction. The pictorial distinction between different lakes is documented in this article. The pictures recorded can readily be transferred to a color model [e.g., Commission Internationale de L'Éclairage (CIE)-Lab]; from there, numerical color parameter values such as hue (h*, the quality of color) and chroma (C*, the intensity of color) may be assigned to each record. There are, however, limitations and obstacles connected with the transformation of color values recorded by a CCD camera (or film digitizers) to absolute numerical values comparable between different cameras and systems. A single CCD camera may be useful for documenting lake color, but there are technical limitations restricting its use as a scientific instrument for quantitative purposes.

WACODI: A generic algorithm to derive the intrinsic color of natural waters from digital images

“…The recipe of this processing, called WACODI, is explained in detail in this article. WACODI represents a large improvement with respect to the work conducted by Klaveness (2005), who concluded that digital cameras could only be used to document visual color differences in a qualitative way. Our findings are in agreement with other authors (Goddijn and White 2006;GoddijnMurphy et al 2009;Hoguane et al 2012) who demonstrated that digital cameras can be used to extract quantifiable results, since they were able to correlate RGB values to the concentration of water constituents, such as Chl a.…”

Lake and Reservoir Management

“…Ground-based measurements on 15 Minnesota (USA) lakes with wide ranges of optical properties and Landsat TM data were used to evaluate the effect of humic color on satellite-inferred water quality conditions and it was suggested that C440 could be estimated with fair reliability from Landsat TM data (Brezonik et al, 2005). Klaveness (2005) discussed the significance of photography in limnology and determined that a single camera might be useful for documenting lake color but there were technical limitations restricting its use as a scientific instrument for quantitative purposes.…”