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Landscape parameters

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PSch
PSch's picture
Landscape parameters

Hello,

I am trying to apply Usetox on a specific geographical region. In this context, I want to enter specific landscape data.

I don't understand the meaning of the "River Flow" column in the "Landscape Data" workseet. I assume that this describes the flow of a river in m3/s, but the unit is labelled "[-]"  for this value. Could you please give me some information about this parameter ?

Thanks.

USEtox Team
USEtox Team's picture
Freshwater discharge

Thank you for your question!

What is called "RiverFlow cont-reg" in the landscape data sheet in USEtox is effectively the fraction of discharge of continental freshwater to the regional scale (sheet Fate, row 62) and is a dimensionless fraction. This fraction is used for calculating the flow of global freshwater to the continental scale (sheet Fate, row 350) and the flow of global freshwater to global ocean seawater (sheet Fate, row 351) - both flows are given in m³/s.

Since the parameter name "RiverFlow cont-reg" is misleading, we will correct it in the next USEtox release version.

dumlette
dumlette's picture
landscape parameters

In addition to the questions made, I would like to ask which cell(s) are adjusted for regional scale? I mean, are we just going to substitute the new values into the continental values/boxes?

 

Thanks

USEtox Team
USEtox Team's picture
User-defined landscapes

Thank you for the follow-up question!

To adjust landscape data toward user-defined values, only parameters in the andscape data, exposure and fate sheets of the USEtox model need to be adjusted. However, it is the responsibility of the user to introduce meaningful values as many parameters related to environmental fate (e.g. residence times) are a function of landscape data (e.g. compartment volumes).

More generally, we recommend to always use the default USEtox landscape parameter values and apply user-specific landscape data only as sensitivity study, as all fate processes are designed as global/continental average values. This means that adjusting landscape data toward more specific, real landscapes or regions does not (necessarily) lead to better representativeness of actual landscapes or regions, but might in fact lead to biased environmental fate behavior if the adjusted data are not properly evaluated.

In the next release version, USEtox will provide - in addition to the default set of landscape data - various continental and sub-continental sets of parameterized and evaluated landscape data to accomodate user requirements. However, also these data are recommended to be only used to test the sensitivity toward the default data set.

dumlette
dumlette's picture
user defined landscape

Thank you for your comments

In this line, may ask additional question related tomy study. I am planning to use USEtox to compare the impacts between two geographical locations. Should I have to use the default values in both cases? Or use specific defined values. Would you also please comment on using USEtox for comparative studies

 

Thanks

USEtox Team
USEtox Team's picture
Comparison of different locations

USEtox is not primarily designed to evaluate spatial differences between landscapes or regions (see previous comments for details), but is build to reflect best estimates at the global scale.

If you have more questions related to your specific study with USEtox, we recommend to attend one of our professional training courses or ask for an individual USEtox training. For our professional training courses, please see Events. Please contact manager@usetox.org for an individual training.