Maybe the Hydromad package in R statistical software might be intersting for you. It offers various methods for hydrograph modelling.

http://hydromad.catchment.org

I'll take a look at it Sir Florian Betz. Thank you.

There are a number of approaches you could use. Depends on what you call the unit hydrograph though. The original unit hydrograph looked only at storm flows, and required subtraction of any baseflows from the observed data. With the advent of models like IHACRES, the unit hydrograph was modified to include the slow flow component (and other components if these can be identified from the data).

Either way, one option is to use the technique described in

https://www.researchgate.net/publication/253953394_Exploring_changes_in_catchment_response_characteristics_Application_of_a_generic_filter_for_estimating_the_effective_rainfall_and_unit_hydrograph_from_an_observed_streamflow_timeseries

This is included in the Hydromad package. One question - what is the size of your catchment? Given that you have 10 and 15 minute resolution data (30 minute if you put them on the same timestep), then if the catchment is large enough, you should be resolving the flow peak. This may cause problems with the technique above, and if so, you will need to modify it to include something like a Nash cascade.

Conference Paper Exploring changes in catchment response characteristics: App...

Dear Dr. Barry Croke,

Thank you for your answer. I'll try to use this method.

For your question, the area for the catchment area is around 377 hectares. Is the area large enough?

Stream flow in the river as base flow and add hydrograph from rain fall data