NetLogo User Community Models
WHAT IS IT?
It is a simple model of SO2 flux, emitted from point sources, to assess its deposition on inland water in a less gauged landscape.
HOW IT WORKS
From a number of sources (n-sources), SO2 will be emitted to the atmosphere at given flux (randomized based on user-defined statistic: SO2-flux-by-source-mean and SO2-flux-by-source-cv). Resistance of the atmosphere (randomized based on user-defined statistic: r-atm-mean and r-atm-cv) defines how much SO2 will be transported in the air through a diffusion mechanism, mainly driven by wind speed (wind-speed) and wind direction (randomized based on user-defined parameter: min-wind-direction and max-wind-direction).
Part of SO2, which are not released to the atmosphere, are assumed to be retained by vegetation and soils [2, 3, 4], depending on their types defining the resistance (r-veg-mean, r-veg-cv, r-soil-mean, r-soil-cv).
Part of SO2, which are not taken by the atmosphere, vegetation or soil, are assumed to be deposited in the water body, either in wet- or dry-deposition.
Finally, the model assesses SO2 content, which are deposited in the water body. In this model, water body is randomized based on parameter defining its coverage fraction (fraction-water-body) in the landscape.
Notes: the model does not simulate SO2 transfer in the soil that might also affect water quality of the streams.
HOW TO USE IT
Adjust the parameters in the sliders. Press “setup” button. And then press “go” button to simulate. Outputs are visualized in the “View” and summarized in the graph provided.
THINGS TO NOTICE
Try to change some parameters that you think it might decrease SO2 pollution on inland water.
THINGS TO TRY
Manipulating wind direction seems to be the most effective way to mitigate SO2 pollution on inland water.
EXTENDING THE MODEL
 Link with GIS
This model mostly uses NetLogo features on patch and agents (turtles).
The model has not been verified. It is developed for the education learning only, as part student seminar for M.Sc Programme at the University of Hohenheim, Stuttgart, Germany (EnviroFood), for the compulsory module: “Ecotoxicology and Environmental Analytics”. Please, do not cite or use the model for research purpose, since it may contain some errors.
CREDITS AND REFERENCES
 Seino N, Sasaki H, Sato J, Chiba M. 2004. High-resolution simulation of volcanic sulfur dioxide dispersion over the Miyake Island. Atmospheric Environment 38: 7073–7081. Resistance of the atmosphere: Platt U. 1977. Dry deposition of SO2. Atmospheric Environment 12:363-367.
 Smith RA and Alexander RB. 1986. Correlations between stream sulphates and regional SO2 emissions. Nature 322(21): 722-724.
 Xu Y and Carmichael GR. 1998. Modeling the Dry Deposition Velocity of Sulfur Dioxide and Sulfate in Asia. Journal of Applied Meteorology 37: 1084-1099.
 Payrissat M and Beilke S. 1975. Laboratory measurement of the uptake of sulphure dioxide by different European soils. Atmospheric Environment 9:211-217.
 Wilensky U. 1999. NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.
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