Hi, I am reading about the Crop Pollination model, and note it applies a spatial weighting to its calculations i.e. ‘it assumes the supply from nearby parcels contributes more than those farther away.’
This is a very valuable feature, as all ES are impacted by spatial weighting to different degrees, depending on scale. My present research is looking at Nitrogen Delivery Ratio, Sediment and Carbon storage. Each are impacted by the ‘nearest neighbour’ pixels of those being analysed by the model. For example, NDR is ‘computed for each pixel based on the properties of pixels belonging to the same flow path’. I’m interested how the resulting data would be impacted by taking into account the influence of pixels adjoining and near to the flow path. Possibly this would provide us a closer approximation of the ecosystem functions we are looking at.
From what I can see from the InVEST documentation, none of the other InVEST models (except for the Urban Cooling Model) explicitly include a spatial weighting mechanism to the respective ES being calculated.
Is it possible that spatial weighting is accounted for in the other ES models by factors already built into their algorithms?
I’d also be interested to hear how other community members have approached this issue. Any thoughts or suggested reading very much appreciated.
Thanks
Richard
Hi @Minton71 , thanks for your post.
The InVEST models certainly vary in complexity and as you note, some incorporate spatial dependencies and some do not. I think “spatial weighting” is just one way to capture the more general phenomenon of spatial dependency. So as you say, models do it in different ways.
Models like NDR, SDR, Seasonal Water Yield do landscape-scale hydrological routing. So like you say, results of a given pixel are influenced by the entire chain of upslope pixels in the flowpath. I think we can call that a spatial dependency.
Yes, for some but not all. If you have questions about a specific model’s alogorithm, the User Guide is a great place to start, and then experts here on this forum can answer more specific questions that come up.
Best,