Responses to the Reviewer #1’s comments:
Thank you for this long-term field study that was interesting to be
read. Some minor comments/suggestion to improve the readability and/or
presentation quality is given in the attached pdf. Main concerns are the
following once:
As you have slightly stressed in the manuscript, your climate
framework is arid to semi-arid. Many statements have been selected
from literature bearing in mind this setting around Beijing.
Therefore, I would suggest to acknowledge this fact by changing
adequately the title of the paper by adding in arid (or arid and
semi-arid) climate conditions to the title. The possible new title
might read: Direct and indirect effects of rainfall and vegetation
coverage on runoff, soil loss, and nutrient loss in arid to
semi-arid climate.
Response: Thank you very much for your comments and
suggestions. We revised the title to “Direct and indirect effects of
rainfall and vegetation coverage on runoff, soil loss, and nutrient loss
in a semi-humid climate” (Page 1, Line 2)
Vertical water balance can only be guessed from Table 1, looking at
Depth and RO data. I would suggest to discuss the elements of the
vertical water balance in your runoff plots into in-depth details. You
were showing vegetation coverage classes, but not much is given with
regard to rainfall partitioning (interception, canopy evaporation,
stem flow, trough fall, …). You are only discussing rainfall (above
canopy I assume), soil moisture (changes), and runoff. There are other
processes that you (some of them) mention, such as infiltration,
evapo-transpiration. But you have not measured them. You have tried in
discussion (using references) to explain the effect of vegetation
(coverage) on soil moisture, infiltration rates or runoff. To better
understand the structure and interrelations in your structural
equation models (SEM), further discussion is needed as vegetation does
not seem to be very relevant environmental factor, especially for
high-intensity rainfall events.
Response: Thank you for your comments. Based on your
suggestion, we have discussed in detail the various processes of
vertical water balance of rainfall (including interception,
evapotranspiration, infiltration, and runoff, etc.) (Page 16, Line
335-341).
You
could check soil erosion rates via any soil loss equation, such as
RUSLE, at least by introducing rainfall erosivity rather than using
separately duration, depth and I30 - this are normally interrelated as
a part of rainfall erosivity R. You could even have checked measured
soil loss rates and modeled ones. I would suggest to try to use SEM by
introducing computed rainfall erosivity R instead of Depth, Duration
and Intensity - i.e. only one rainfall factor. In such a way your
results will be much more comparable to a vast literature on rainfall
erosivity and their effects on soil erosion. As you have measured not
only soil loss, but also nutrient, this is important to relate
nutrient (P, N) loss to rainfall erosivity. I am sure you can find an
adequate equation for rainfall kinetic energy to be used in the
expression EI30 for the region of Beijing. As you will use the same
equation for all plots and events, the choice of the equation is not
critical. The units of R will allow you to compare your results with
many other studies.
Response: Thank you for your comments. We found a formula for
calculating the rainfall erodibility which is suitable for Beijing[1] and added the rainfall erodibility into the
structural equation model (Page 8, Line 155-159; Figure 5,7,8).
[1] Liu, B., Bi, X., Fu, S.
(2010). Beijing soil loss equation [M]. Science Press. 22-23