I have a .csv file containing data for stream discharge, stream flashiness, and precipitation over 15 minute intervals from 2010 until 2022. The format of my file is
Date, Time, Discharge, Flashiness, Precipitation 2010-05-01, 0:00:00, 0.299, 0.0, 0.0 2010-05-01, 0:15:00, 0.319, 0.020, 4.6 2010-05-01, 0:30:00, 0.371, 0.052, 3.1
In the .csv file mentioned above, "Date" is the date ranging from 2010-05-01 to 2022-10-31, "Time" is the time of day (measured in 15-minute intervals), "Discharge" is the discharge measurement from the hydrometric streamflow gauge at each time interval, "Flashiness" is the increase in stream discharge at each time interval (compared to the discharge at the previous time interval), and "Precipitation" is the precipitation depth that has fallen over each time interval.
Incremental disturbances have been added to the watershed (2013, 2016, and 2019), and I want to be able to test whether (and the extent to which) these disturbances change the "Flashiness" in response to "Precipitation". i.e., is the relationship between precipitation depth and the corresponding increase in stream discharge statistically different before 2013, between 2013 and 2016, and after 2019? Does anyone have any advice on how to approach this?
I want to be able to create a model and see if the 15-minute interval flashiness response to precipitation is statistically different over the four time periods (i.e., the time period before the first disturbance (i.e., 2010 to 2012), the time period between the first and second disturbance (i.e., 2014 to 2016), the time period between the second and third disturbance (i.e., 2017 to 2019), and the time period between the forth disturbance and the end of 2022 (i.e., 2020 to 2022)). Each of these four time periods (i.e., 2010 to 2012, 2014 to 2016, 2017 to 2019, and 2020 to 2022) have an equal sample size (i.e., three years of daily data).
I am unsure how or what tests could be used to determine if stream flashiness in response to precipitation is statistically different between time periods. I would appreciate any feedback or suggestions that anyone may have as I have no idea what I am doing at this point.