2.2.4 Soil water storage variation in the rainfall process
and growing season
In our study, we defined the absolute increase in SM (AIM ,
vol.%) at each measurement location as follows:
AIM = SMe - SMs (4)
where SMe (vol.%) and SMs(vol.%) are the SMs at the end time of the soil wetting process and at
the start time of rainfall, respectively. Additionally, we calculated
the soil water storage variation at the 100 cm soil depth
(SWS0-1m , mm) after each rainfall process:
SWS0-1m =\(\sum_{i=1}^{5}{\text{AIM}_{i}\times D_{i}}\times 10\) (5)
where AIMi represents the absolute increase in SM
at layer i. Di is the thickness of each depth interval.
Then, the rainfall transformation rate (RTR , %) was calculated
as follows:
RTR = SWS0-1m / R1-13 × 100% (6)
Where R1-13 is the total rainfall amount from the
P1 to P13 rainfall processes. Additionally, we compared the averaged SM
profile and total soil water storage variation
(SWStotal ) for the 6 months among the study
sites:
SWStotal=\(\sum_{i=1}^{5}{\text{AVM}_{i}\times D_{i}}\times 10\) (7)
where AVMi represents the absolute variation in SM
across the entire monitoring period at layer i.