Beginner questions

[Janet Thorndike]

Hi!

I am new to InMAP and have been reading online tutorials and related journal articles but still have some basic questions:

1. Is it possible to use alternative Census and mortality data with the source-receptor version? Or, is it OK to merge emissions output from the SR version to new Census and mort data? I see that the size of InMAP output areas is determined by population density, so that's why I ask the latter question.

2. Does the transportation of pollutants depend on weather data that should be updated depending on one's time period? (I am using InMAP for the US.)

3. Many descriptions of output variables indicate that InMAP gives the *change* in PM2.5 concentration from emissions inputs, from the model's created baseline. However, the source-receptor tutorial (https://www.inmap.run/blog/2019/04/20/sr/) suggests that the SR version simply returns absolute emissions concentrations from inputs, not a change from a baseline. Is this correct?

Thanks everyone!

Janet

[Anil Gogebakan]

Hi Janet,

I'll do my best to answer your questions:

1. Yes, you can integrate your own mortality and census tract data into SR to calculate things more precisely. However, since you mentioned you're just beginner, I would recommend using the built-in census and mortality data and following the average growth rates in the tutorial. I did integrate my own data before, but the results weren’t significantly different. It's better to stick with the default settings for now to get quick and easy results. You can always revisit custom data later when you're more comfortable. Here's the tutorial: https://inmap.run/blog/2019/04/20/sr/

Also, one of the great features of inMAP is that it adjusts calculations based on population density grids, which makes the results more accurate.

2. I believe that technical factors like gradient, wind currents, and temperature won’t change significantly over the years, but I’m not 100% sure. This is more related to the engineering side of the model, so the developers of inMAP might have a more detailed answer. At this stage, I wouldn't worry too much about this aspect.

3. I’m not sure where you saw mention of "absolute" emissions changes, but inMAP calculates marginal emission changes for each geographic cell. These can easily be translated into marginal avoided mortality (in cases of emission reductions) for each geographic cell. The software uses complex calculations to reflect real-world conditions as closely as possible, so it doesn't give absolute changes.

Please feel free to correct me if I’ve misunderstood anything or if any of this information isn’t accurate—it’s just based on my own experience.

I hope this helps!

Anil G.

[Janet Thorndike]

Thanks, Anil.  Can anyone provide specific answers to my remaining questions? 

 1. Given the way that InMap determines the sizes of output areas, is it important to integrate census population (and mortality) data into the modeling process, or would it be OK to use the SR version  generate emissions results and simply merge them with alternative census and mortality data? 

2. Does the transportation of pollutants depend on weather data that should be updated depending on one's time period? (I am using InMAP for the US.)

3. The use of 2016 data and the discussions of results in the InMAP SR tutorial suggest that the results are an absolute terms, not relative to a baseline.  Can someone please confirm?