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Seasonal Water Yield - CN and Kc Values - Biophysical table

Hi all,
I am new to the forum and InVEST but I have been using GIS for about 15 years. 

I am attempting to find the values to insert into the biophysical table for the seasonal water yield model. Does anyone know where I might find CN and Kc values for tropical montane rainforest, specifically the Atlantic Rainforest in Brazil? Even generic tropical rainforest CN and Kc values would be helpful. Also, CN and Kc values for *tropical* crop/ag land and pasture would be helpful too, if at all possible.

The data source for the InVEST user guide just lists several natural forest types that are for the US (ie

Any help that you all could give me would be much appreciated! Thank you!


  • Hi

    I am a InVEST model user.
    now I have an actual case., Water in a river in watershed has dried up in summer, it's never been like this before. someone said that because the pumping of water from the ground up (at the lower altitude) by the housing area nearby the river.
    I have a question, How can i use the seasonal model to proof this assumption ?

  • RichRich Administrator, NatCap Staff
    Sorry @dhamma57, I'd suspect the seasonal water yield model is not suitable for such a local and specific proof.
  • swolnyswolny Member, NatCap Staff
    Yes, I agree with Rich, that this model isn't suitable for your case. You'll probably need a more detailed model that captures a lot more of the groundwater/surfacewater interactions, as well as how it's being used by the housing area. The seasonal water yield model is made for showing where the landscape contributes to dry season baseflow and runoff, but your case is not so much about the landscape, but about very specific point extraction. 

    ~ Stacie
  • OK, Thank you
  • Hi

    What is the Hydrological Soil group for the water body area such as a lake ?
    and what is the runoff curve number (CN) for water area?

  • PerrinePerrine Moderator, NatCap Staff
    The hydrological soil group can be set to the soil underlying the lake. However, the value does not matter too much since the curve number is typically set to a very high value, to reflect the fact that the runoff from these areas is high (directly contributing to streamflow).
    Keep in mind that these are model simplifications when interpreting model outputs in the region of the lake.
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