The file "data.xlsx" is divided into 3 sheets.

(sheet 1) Hydraulics 
Measured volumetric discharges (l/s) are the averages among at least 5 different
replicas performed in the representative segment, a 13 m reach portion, within one hour. 
Travel times (s) in the representative segment in natural conditions - without the plastic 
film over the streambed - and covered conditions - with the plastic film over the streambed 
- are given as mean values of 3 consecutive tests. 
Longitudinal mean velocity (m/s), in covered conditions, was estimated as the segment length 
divided by the observed travel time. Mean width (m) and mean water depth (m) are the spatial 
averages of the local values observed in different cross sections along the reference segment.

(sheet 2) Damping factors
Mean and standard deviation of measured CO2 concentrations (ppm) upstream and downstream 
the steps of drop height Δhi (cm) and observed in the two endpoints of the representative segment.
In the orange rows the estimated damping factors, fcr and fsi(Δhi), with Ca = 400 ppm.

(sheet 3) Dominance ratios
The values of r for the three reaches used in the upscaling (A, B and A*) were calculated 
from the spatial frequency of steps, λΔh, with a given drop height included in the reach and
using a linear empirical law to link fsi to Δhi (fsi = 0.3 Δhi with Δhi expressed in m). 
The surveyed step heights were divided into classes and the corresponding spatial frequency 
was defined by NΔh, the number of steps with a height range around Δh in the considered reach.
The equivalent length of reach A* was calculated through a proportion between vertical gradient 
and length in the representative segment and in the continuous part of A.