Precipitation monthly data preparation

Dear all,
The precipitation monthly data is raster. I am wondering how to prepare for long-term years of rainfall data?. Your answers will be appreciated.

Dear Vanna,

From what I know for the Seasonal Water Yield module, I believe you can either run the program as a batch process over different folders of precipitation data (monthly raster) for every particular year you are interested in. Or, you could take the yearly average for each month.

Best regards,

Felix

Dear Felix

I would thank so much for your answers. If I want to run for 10 years of rainfall, from your experiences, is it a good way to create 10 folders of monthly precipitation data (raster) and then to get the model run for 10 times of each folder?. By the way, at first I will try to run as a batch process.

Best regards,
Vanna

Hi @Vanna -

Our freshwater models (like Seasonal Water Yield) are made to look at averages over the long term. So we generally advise having at least 5, preferably at least 10, years of precipitation data, then averaging over those on a monthly basis to create the average monthly precipitation rasters for the model (one for each month). Technically, we can do a model run with a single year’s worth of data, but I’d be interested to hear @RafaSchmitt’s take on what the limitations of that would be.

What kind of precipitation data are you starting out with? If they are point data (like rain gauges), you would calculate the monthly average value for each month and each point, then use an interpolation tool in GIS to turn those points into a raster. There are multiple interpolation tools that can be used, and they’ll produce different patterns, so you’ll probably want to try several, to get a pattern that makes sense to you, based on your knowledge of the study site. There are also ways to take elevation into account, which might be important in mountainous places. Sorry that I don’t have a specific pointer to methodology, but you can find information with a web search.

~ Stacie

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