MINIMUM TIME SPAN REQUIRED FOR DATA SETS IN WATER YIELD MODEL

How many years of climatic data are needed to run the InVEST water yield model? Can I use yearly data? Please let me know.

Comments

  • swolnyswolny Member, NatCap Staff
    Hi @manas -

    The InVEST water yield model uses annual average precipitation and potential evapotranspiration as inputs. You may either get these already prepared (as in global climate products like WorldClim or from CGIAR) or prepare them yourself from local weather station data. Either way, the annual average should be taken over a long time span, preferably at least 10 years worth of data, where there are no (or few) gaps of missing data within those years (some places only monitor, say, seasonally, or stopped for a few years and started again...) If you are preparing your own and would like more direction, let us know.

    ~ Stacie
  • manasmanas Member
    Thanks swolny for your clarification.actually I have 27 years of climate data. so can I run the the model for the time gap of 10,10,7 years?

  • swolnyswolny Member, NatCap Staff
    What is the purpose of the analysis? In general, I'd say that the two 10-year periods are fine, the 7-year period less so but borderline (I'll leave it up to a hydrologist to make that call.) Do you also have observed flow data for those periods that you're calibrating/validating against?

    ~ Stacie

  • manasmanas Member
    Yes I have all the observed flow data for whole time period of 27 years @
  • PerrinePerrine Moderator, NatCap Staff
    Hi Manas, 

    I agree that the model shouldn't be used with an annual time step.

    Using three periods as you suggest is definitely possible. If the periods have distinct climate characteristics (e.g. a 10-yr drought, then a wet period, etc.), this allows to verify that the model correctly represents these periods. 

    It is often useful when you assess climate change scenarios, where you run the model under different precipitation regimes (e.g. a drier climate).

    Best,

    Perrine
  • Thank you Perrine

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