Historical Evolution of Sources and Pollution Levels of Heavy Metals in the Sediment of the Shuanglong Reservoir, China
, Yongping Wang 1, Haowei Teng 1, Hao Yang 2, Aiju Liu 3, Menghong Li 3 and Xiaoyin Niu 3,*Round 1
Reviewer 1 Report
This is the review of the manuscript water-825966, namely "Historical Evolution of Sources and Pollution Levels of Heavy Metals in the Sediment of the Shuanglong Reservoir, China" by Zike ZHOU, Yongping WANG, Haowei TENG, Hao YANG, Aiju LIU, Menghong LI
and Xiaoyin NIU for publishing in Water
General Comments:
This manuscript describes the (1) analysis the profile distribution of heavy metals (Cr, Ni, Cu, Zn, As, Hg, and Pb) in the sediment of typical water-supply reservoirs in a small watershed, (2) contamination levels of heavy metals in the sediment using multiple assessment indices (Ig, PLI, Pi, Er, RI, and PN), (3) source of heavy metals using statistical analysis (principal component analysis [PCA], correlation analysis, and coefficient of variation [CV] analysis) and historical data in order to provide a valuable tool to improve the management of aquatic environments and implement water and soil conservation.
The scientific research looks very good. I accept manuscript in present form.
Author Response
Cover letter
Dear Reviewer and Editor:
Thanks for the reviewer's affirmation to our title “Historical Evolution of Sources and Pollution Levels of Heavy Metals in the Sediment of the Shuanglong Reservoir, China” (ID: water-825966). In addition, your comments are of great help to the revision and improvement of our paper. We have polished the full text and hope to get your approval.
We appreciate for Editor/Reviewer’s warm work earnestly, and hope that the correction will meet with approval.
Thank you and best regards！
Yours sincerely,
Zike Zhou
Reviewer 2 Report
This MS explores the levels of heavy metals and metaloid (As) in a sediment core from the Shuanglong reservoir. Although this topic is interesting, one of the goals of this MS is to implement water and soil conservation. However, only sediment evaluation was done. Please note that As is not an heavy metal but a metaloid. Although pollution level of the Shuanglong reservoir was considered low, sinergistic effects must be considered.
Other comments:
L.14 - was investigated
L.20,21 – Please rephrase sentences to avoid the repetition of word “analysis”
L.30 – please note that pollutants may also accumulate in water.
L.38 – please specify on secondary pollution.
L.48 - please specify why small watersheds contribute more to the downstream aquatic environment than large ones.
- 162 - Table 2. Levels of …
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
