the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 09 Oct 2024
Drought propagation in high-latitude catchments: Insights from a 60-Year Analysis Using Standardized Indices
Abstract. Droughts, traditionally less associated with high-latitude regions, are emerging as significant challenges due to changing climatic conditions. Recent severe droughts in Europe have exposed the vulnerability of these northern catchments, where shifts in temperature and precipitation patterns may intensify drought impacts. This study investigates the dynamics of drought propagation in high-latitude regions, focusing on four key aspects: (1) the typical lag time for drought conditions to propagate from initial precipitation deficits to impacts on soil moisture, streamflow, and groundwater systems, (2) the probability of precipitation deficits leading to these droughts, (3) the key factors influencing drought propagation, and (4) how drought propagation has evolved under changing climate conditions. By analyzing long-term observational records from 50 Swedish catchments, the study reveals that drought propagation is highly variable and influenced by a complex interplay of catchment characteristics, hydroclimatic conditions, and soil properties. Soil moisture exhibits the shortest propagation times, often responding within a month to precipitation deficits, while groundwater shows the longest and most variable response times, sometimes exceeding several months. The probability of precipitation deficits propagating into soil moisture droughts is highest, followed by streamflow and groundwater, with these probabilities increasing over time. Across all drought types, annual precipitation and streamflow are the strongest governing factors, driving both propagation time and probability. Despite ongoing changing climate, drought propagation times or probabilities have not significantly changed over the past 60 years. However, while most catchments are becoming wetter across all seasons, southern catchments become more vulnerable to spring drought due to increased evaporative demand. These findings highlight the need for tailored, region-specific water management strategies to address seasonal and regional variations in drought risks, particularly as climate change continues to evolve.
- Preprint
(2747 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 11 Dec 2024)
-
RC1: 'Comment on egusphere-2024-2742', Anonymous Referee #1, 16 Oct 2024
reply
The manuscript is comprehensive, well written, and organized. The four research questions outlined in the introduction are properly addressed in the results and discussion sections, although the results and discussions can be more objective. The justification provided for novelty is the lack of knowledge of drought propagation processes in regions of high-latitude catchments such as Sweden. The figures are informative and well presented, with only minor comments for improvement. As a suggestion for future research, it would have been very interesting and novel to visualize the drought propagation results between drought types, drought events, and/or catchments or clusters with cascading Sankey plots or network graphs. The results section could be more objective by focusing on the most important findings, it is not necessary to report everything that can be read on the figures or tables. Therefore, I suggest focusing on the overall patterns and outliers for clarity. In the discussion section, I would suggest aiming mostly at answering the proposed research questions and describing how the main results are linked to targeted management practices in terms of drought propagation dynamics. Overly broad statements and generalizations in the discussion can be shortened or removed for conciseness. Apart from summarizing the most important results in Sweden and how they agree with previous literature, the discussion should also reflect on the research gap and highlight the differences against other regions in the world. How unique are drought propagation patterns in Sweden or in high latitudes in general? Please highlight and emphasize in the introduction and discussion sections what are the potential new insights and main findings from this paper regarding drought dynamics that have not yet been covered in the literature. Please also include some discussion on the limitations of the modelling approaches and assumptions. In summary, I consider that the scientific and presentation quality of this manuscript are excellent, and the scientific significance is good but could be improved by highlighting and distinguishing the knowledge contributions on drought dynamics from this application in Sweden. Therefore, I recommend accepting the manuscript with minor revisions.
Line 154: Why was the SPI index chosen over the SPEI? The SPEI, which includes evapotranspiration, would have the advantage of considering temperature in its formulation. Increasing temperatures due to climate change tend to increase evapotranspiration, leading to raised drought effects that could counteract the wetting trend in Sweden. This process is not directly considered in the SPI or the other indices. As mentioned in Line 632, increased evaporation could potentially explain why available water is not being retained in some systems. Please comment on this.
Line 202: Please justify why SPI is taken as the reference for propagation time and probability analysis instead of any of the three other indices.
Line 205: Is this study the first expanded application of this approach for streamflow and soil moisture drought? If so, I suggest mentioning this and other possible methodological advancements in the introduction.
Line 338: Why are probabilities for soil moisture drought propagation during summer so much more pronounced than for other seasons and other drought types?
Line 467: Please elaborate and exemplify management strategies that are specific to long-term groundwater droughts as opposed to other drought types, highlighting the application of your findings into practice.
Line 493: Please include examples from the literature of rapid response measures.
Lines 499-503: Those appear to be generic statements that would better fit the introduction section than discussion.
Figure 2: Please correct the following typo in the figure caption: ‘tempereature’.
Figure 4: Why is the spacing of the latitudes (y-axis) inconsistent? Please readjust for equal spacing if this is unintentional. I suggest changing the colormap so that no data is shown as white instead of black for improved contrast and readability, as in Bloomfield and Marchant 2013 Fig. 11.
Figure 6: For improved clarity, I suggest writing the names of the corresponding indices in front of the labels b), c) and d).
Figure 10: Why is the presentation between annual and seasonal shifts different? It would have been more informative and consistent to show seasonal shifts also as boxplots.
Citation: https://doi.org/10.5194/egusphere-2024-2742-RC1 -
RC2: 'Comment on egusphere-2024-2742', Anonymous Referee #2, 19 Nov 2024
reply
Please see attached PDF file.
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 159 | 43 | 7 | 209 | 3 | 4 |
- HTML: 159
- PDF: 43
- XML: 7
- Total: 209
- BibTeX: 3
- EndNote: 4
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1