The Decrease in Lake Numbers and Areas in Central Asia Investigated Using a Landsat-Derived Water Dataset

Round 1

Reviewer 1 Report

The manuscript analyzes the number, area, and spatio-temporal dynamics of the lakes of Central Asia from 2000 to 2015. An interesting and useful study with appropriate topic for Remote Sensing Journal. I recommend publishing this manuscript because regional studies of lake dynamics in Central Asia are rare and it is a step towards a higher spatial and temporal resolution analysis of lake dynamics in Central Asia. This manuscript can be accepted when the following detailed comments are addressed/corrected:

• Please provide sufficient explanation and references in the introduction for the sources of uncertainty of the global surface water explorer.
• Please add unit to the DEM at the legend of Figure 1.
• Please pick a more distinct color for Window size and Stack-out in Figure 2.
• I don’t see 16 colors in the legend of Figure 8 representing 16-year study period.
• Please use more distinct colors to show the water occurrence in Figure 10 and 11 especially for 2014, 2015, and 2016.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Overall, I am pleased with the thoroughness of the study. Here are my minor comments:

1. The title sounds a bit verbose, so would recommend shortening it if feasible
2. In the abstract, "strong power exponent relation (R2:0.95 and ?:-0.602) between the size and number of lakes in Central Asia, which indicates that the region has a higher portion of large lakes than the globe " is presented as if it is one of the main findings. I don’t believe it is, so recommend removing it.
3. Decrease in lake area: can you put it in the % of the total lake area?
4. "Due to the 16-day revisit cycle of the Landsat sensors and contaminations of clouds, cloud shadows, haze, and ice and snow, valid observations for a specific month can be sparse or non-existent. " can you provide a sense of how frequent these interruptions are? E.g. 10% of the total months
5. Table 1: No need to mention Canadian/ US data sources for HydroLakes, since they are irrelevant to the study area.
6. Figure 6 can benefit from more description in the caption.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The paper of Che et al. analyses 16 years (2000 - 2015) of the changes in Central Asia lakes in response to climate changes. This paper brings useful information to the earth science community by assessing the evolution of lakes surface and number in a poorly studied region. 

The manuscript is well written and organized and the interpretations are supported by clear explanation and by clear figures. The content and the analysis are very consistent and supported by a robust statistical approach. The methods are well explained and mastered by the authors. The good data analysis and interpretations are supported by clear explanation and by clear and clean figures. The results support the conclusions. There are no objective errors.

I have several concerns which I want to address below. 

The analyses were based on Hydro lakes global database, but since I am not familiarly with this database I don`t know what are the uncertainties related with this database. Is it possible to refer to this issue within the Methodology? Are there any papers assessing the uncertainty of this global database?

 The results show very nice an obvious decreasing trend of both the number and area of lakes. Unfortunately, the forcing factors of this tendency are insufficiently discussed. It is not clear to what degree the decreasing is due to precipitation reduction/evapotranspiration increase/another factor.  Would be good if possible to include in the paper a graph with temp and pp evolution at several meteo station in the study region. 

I am sure that the decreasing trend of lakes was also documented for other regions. Within the Discussion, you may compare your results with similar results from other parts of the world. 

What about the permafrost occurrence in your study area and the relationships with lakes? It was shown in many different studies in the Arctic and high mountains that thermokarst lakes reveal a particular pattern. Please refer to this within the Discussions. Maybe the expanding lakes are also where permafrost is thawing.

Author Response

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