Subject: Weighted mean of high and low temperature: Soil Moisture Method Posted: 6/24/2016 Viewed: 2356 times
Hello WEAP community,
Under the rainfall-runoff (Soil Moisture Method) in WEAP, temperature is defined as the ‘Weighted mean of high and low temperature’? Could anyone please clarify what this means and how this value can be calculated?
For the case of my study area, temperature data are available in different forms and resolutions. Temperature is provided as on hourly basis, on daily basis as Maximum and Minimum values within each day, and on Monthly basis (i) Maximum and Minimum values for each month, and (ii) Mean Maximum and Mean Minimum Values for each month?
As I am intending to run the model using a monthly time step, and utilising the ReadFromFile wizard (i.e. time series for each catchment) how can I generate the appropriate temperature value to be used in rainfall runoff method to model my catchments?
Your answer is highly appreciated
Subject: Re: Weighted mean of high and low temperature: Soil Moisture Method Posted: 6/26/2016 Viewed: 2315 times
The soil moisture method, when used monthly, needs temperature inputs for each month for each catchment. This has to be a single record of one temperature value/catchment/month. How you arrive at that number is up to you - you could use the average of maximum and minimum daily values, you could average the monthly maximum and minimum daily values, you can weight maximum values more than minimum, or vice versa. Average monthly temperature is common to use, but you could argue that your basin is different and use another representative temperature, it depends on your knowledge of your system. Modelers have to make a lot of judgment decisions, and you'll see the result of these decisions as you calibrate the model.
I would generate the time series within a Excel for CSV file, for simplicity's sake, and then use the ReadFromFile wizard.
Subject: Re: Weighted mean of high and low temperature: Soil Moisture Method Posted: 6/28/2016 Viewed: 2307 times
Thanks very mush for your answer and clarifications
Topic "Weighted mean of high and low temperature: Soil Moisture Method"