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DSD-INT 2015 - web application - pascal boderie
This document discusses a web application called UITZICHT that simulates Secchi depth and light penetration in water. It models the complex interactions of light underwater, which is impacted by inherent optical properties like absorption and scattering, and apparent optical properties like Secchi depth. Key factors that influence light levels include chlorophyll, total suspended matter, inorganic solids, colored dissolved organic matter, and bottom depth. The application was developed by converting the original FORTRAN code to JavaScript so it can run on any browser and be easily shared. It simulates optical properties of water based on parameters from a 1995 publication by Buiteveld.
DSD-INT 2015 - web application - pascal boderie
- 1. 30 november 2015 Webapplication for simulation of Secchi depth and Kpar UITZICHT DSD 2015 Pascal Boderie
- 2. Light under water Importanceof light and visibility (Secchi depth) • ecology (primary production) • photolysis – decay of pollutants by uv light • water temperature – influx efficiency (ir) and visibility • public • Modelling light is quite complex • many definitions - radiance (source) en irradiance (receiving) • IOP en AOP • Light reflection • PAR (400-800 nm) not equal to human eye sensitivity 30 november 2015
- 3. Light under water InherentOptical Property – independent of the light field: • Scatter coefficient, b • Absorption coefficient, a • Beam Attenuation, c ( sum van a’s en b’s) Apparent Optical Properties – depending on light field • Secchi disk depth (SD, m) • Irradiance attenuation coefficient (Kd, 1/m) 30 november 2015
- 4. Ecological key factors2 - Light 30 november 2015
- 5. Institute Optical active waterquality parameters Chlorophyll Pigments (mg/m3) CHL Total Suspended Matter (g/m3) TSM Inorganic fraction of TSM (g/m3) ISM Coloured Dissolved Organic Matter CDOM Water plants (macrophytes) floating - submerged Bottom (depth: m) Secchi Depth (m) SD
- 6. 6 * * * C C NAP NAP yy a a Chla a a NAP a a CDOM * /2 2 ( )sin( ) d NAP NAP b b b NAP b b b B wavelength a*_H2O b*_H2O a*_CHL b*_CHL a*_NAP b*_NAP a*_CD OM 413 0.01 0.007 0.023 0.005 0.035 0.43 1.28 442 0.01 0.005 0.025 0.005 0.026 0.41 0.98 490 0.02 0.003 0.015 0.018 0.017 0.38 0.64 510 0.03 0.003 0.012 0.019 0.014 0.37 0.54 560 0.07 0.002 0.006 0.024 0.011 0.35 0.34 617 0.28 0.001 0.006 0.018 0.008 0.32 0.2 665 0.4 0.001 0.011 0.008 0.006 0.31 0.13 681 0.43 0.001 0.009 0.013 0.007 0.3 0.12 708 0.71 0.001 0.002 0.033 0.005 0.29 0.09 PAR (400-700) 0.035 0.005 0.011 0.016 0.011 0.35 0.34 mm 1/m 1/m mg/m2 mg/m2 g/m2 g/m2 1/m Absorption & scattering B~0.03
- 8. Publication of Buiteveld(1995) 30 november 2015
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- 10. 30 november 2015 Uitzichtpublication (Buiteveld, 1995)
- 11. Technical aspects • OriginalDelwaq FORTRAN code to Javascript • HTML with style-sheet • GUI in Javascript • All code is readable (ascii files) • Runs on any (?) browser (IE > 8) • “Light” easy to share • Works on tablet and mobile phone web demo http://www.andriks.net/uitzicht/nl/uitzicht.html 30 november 2015