The authors demonstrated detection of debris flows in Wenchuan area, China using a self-designed system, and analyzed the data to obtain important characteristics of the debris flow with the goal of establishing “a cost-effective, dependable, and convenient approach for monitoring debris flows in intricate mountainous terrains”.

The data itself is unique and valuable; however, I have significant concerns about the seismic processing approach and remain unclear about the monitoring system's effectiveness for early warning.

Major comments:

The rationale behind the compensation step is not understood, especially when there is a large uncertainty in attenuation or the Q factor, and therefore the reconstruction of the signals. In addition, most of the detection analyses would not need to compensate for Q and the reconstruction, especially if the debris flow monitoring system is so close to the source. This problem is compounded in the power spectral density (PSD) where the equation has already accounted for attenuation and therefore is contributing to conflicting values.  

On Section 3.2 Cross-correlation and for Section 4.2 Debris flow analysis: What part of the recording is cross-correlated: the seismic power, absolute amplitude, envelope of the amplitude in time-domain? And if you use the whole debris flow signal, or just the onset. My concern is that the high frequency recording is complex and will generally give poor cross-correlation value. The peak frequency (in equation 6) can be used as a proxy to distance too, and can be used to calculate flow velocity and cross-check with the velocity obtained from cross-correlation.

On Section 4.3.3: seismic power spectral density (PSD) curves: Is this analysis done on the raw data or the compensated data? Equation 6 has accounted for attenuation. The analysis is only done for one station, but given the setup of dual monitoring systems and that most parameters like grain size would be the same, it would be useful to perform the analyses on both stations and explore the effectiveness and value in having a dual monitoring system.

In the context of “Subsequent debris flow detection, early warning, and inversion”, It would be helpful to discuss how effective the system is in dealing with false detections such as local earthquakes or quarry activities. The emphasis on early warning is compelling and clearly important, yet the discussion on how the system or its processing steps contribute to early warning is quite limited.

Another point is on cost-effective, which brings the question of why we need a two-station monitoring system. Presumably for redundancy, but this design choice warrants a longer discussion, especially considering their proximity (less than 1 km apart) and most of the calculations can be done with a single station.  

Other comments:

Highlights:

• Real-time monitoring of debris flow kinematics based on seismic signals.
• Extraction of debris flow characteristics (e.g., peak velocity) over space/time.
• Provides a framework for upscaling debris flow monitoring networks.

These highlights are not reflected in the manuscript. As written in the text, the monitoring is not done in real-time. Similarly, the term ‘Peak velocity’, is only mentioned once in this highlight and not in the text. The manuscript mostly demonstrated the data analyses and there are little to no discussion on the framework for upscaling.

Abstract: “Our analysis of infrared imagery and power spectral density showed a strong correlation between debris flow seismic energy and its frequency spectrum, supporting the accuracy of using seismic signals to reconstruct debris flow events.”

- This is ambiguous. Which observable is strongly correlated to which physical properties of the debris flow?  

Introduction: “Landslides involve the movement of rock and soil on slopes, slipping along shear surfaces (Yan et al., 2020).”

- This first sentence is not related to the overall manuscript. Please remove self-citation.

Line 68: Alternative approaches use flow velocity and depth as primary indicators for monitoring and early warning

- This is ambiguous. Is it debris flow velocity and depth?

Line 76: showcasing the effectiveness of ultrasonic and radar devices for monitoring.

- Similarly, this is ambiguous. From the sentence it is unclear if it is actually effective or not.

Line 84: Belli et al. (2022) found that physical parameters of debris flows correlate positively with seismic signal amplitudes.

- Which physical parameters?

Line 208: …. successfully recorded debris flow events.

- Ambiguous. Did all the instruments in the monitoring system recorded the event?

Figure 4. error in captions and lettering in the figure.

- Which station is which panel?

Line 387; From the compensation spectrum curve, the high-frequency components have been significantly restored, and both sites show similar improvements in their spectrum curves (Figure 5).

- What has changed in the spectrum curves for the raw and compensated signals, and why is it considered improvements?

In Figure 6, is the data raw or ‘restored’? 

For Table 2, what data went into determining the times? The point of the detection is to use the monitoring station independent of other sources (like local villagers reporting) to obtain the start time. I recommend listing the start times estimated from all the instruments in the monitoring system (seismic, infrared), and then comment on how these times match or differ with those from the local villagers and/or other types of observations.

Line 438 to 462.  It is very hard to understand the process from the writing. Suggest using a schematic or timeline instead. Also, it is unclear what “number of waves” is.

In Figure 7, please show the raw data as well like in Figure 5.

"Infrared cameras are cheap, plus solar energy about $ 78, and Hikvision 's infrared video camera plus solar energy about $ 425."

- Incomplete sentence: Solar power costs about $78….. Also, what is the cost of infrared camera and how is it different from Hikvision’s infrared video camera?

“… Around 1693.9 to 1042.2 hours”

- Usually this is written in increasing order. Around 1042.2 to 1693.9.

Line 203: “The earthquake monitoring system was in continuous operation at most from July 2023 to March 2024, which corresponds to a monitoring period of 9 months.”

- Don’t think you need the phrase “at most” Please use a grammar checker and pick up any missed errors in other sentences

Line 216: For better readability: However, due to the lack of a network signal, real-time transmission of the recorded data via the Internet/GSM is not possible.

Line 233: incomplete sentences in section 3.

Line 374: practical investigations … petroleum seismic techniques

- Ambiguous. Which seismic techniques.

Figure 10: missing caption. Where is (h) and (i)?

Line 723: “many of the analyses in this study are mostly preliminary and lack a certain degree of accuracy”

- This sentence is very unspecific. Which analyses is preliminary, and how inaccurate are they?