Pub Date : 2024-12-01Epub Date: 2022-02-28DOI: 10.1177/15347346221082776
Wen-Hui Yu, Tong Zhang, Heng Xu
Background: Patients with diabetes mellitus face difficulties in wound healing. It is important to explore therapeutic options for diabetic complications such as ulcers. This study evaluates the role of dipeptidyl dipeptidase 4 inhibitors (DPP4i) in the management of diabetic foot. Methods: Literature search was conducted in electronic databases (Google Scholar, Ovid, PubMed, Science Direct, and Springer) and studies were selected for inclusion if they reported the incidence rate of diabetic foot ulcer during DPP4i treatment or evaluated the effect of DPP4i on wound healing. Incidence rates of foot ulcer, amputation and peripheral vascular disease were pooled to achieve overall estimates. Meta-analyses of odds ratios were performed to evaluate the risk of foot ulcer, amputation, and peripheral vascular disease with DPP4i, and to examine the effect of DPP4i treatment on ulcer healing. Results: Ten studies (532354 DPP4i and 2092010 non-DPP4i treated diabetes patients) were included. Incidence rates of foot ulcer, amputation, and peripheral vascular disease were 3.80 [95% confidence interval (CI): 0.22, 7.39], 0.82 [95%CI: 0.60, 1.05], and 22.33 [95%CI: 9.14, 35.53] per 1000 person-years respectively in patients treated with DPP4i and 3.60 [95%CI: 1.77, 5.39], 0.76 [95%CI: 0.58, 0.94], and 20.9 [95%CI: 16.04, 25.81] per 1000 person-years respectively in patients treated with non-DPP4i drugs. Risk of ulcer or amputation with DPP4i was not consistent across studies. Odds of non-healing of ulcer were significantly lower with DPP4i in comparison with controls (odds ratio: 0.27 [95%CI: 0.10, 0.71]; p = 0.008). Conclusion: Incidence rates of diabetic foot and amputation are found to be similar with DPP4i and non-DPP4i drugs. DPP4i improved wound healing of diabetic foot in 3-month randomized trials.
{"title":"Role of Dipeptidyl Dipeptidase 4 Inhibitors in the Management of Diabetic Foot.","authors":"Wen-Hui Yu, Tong Zhang, Heng Xu","doi":"10.1177/15347346221082776","DOIUrl":"10.1177/15347346221082776","url":null,"abstract":"<p><p><b>Background:</b> Patients with diabetes mellitus face difficulties in wound healing. It is important to explore therapeutic options for diabetic complications such as ulcers. This study evaluates the role of dipeptidyl dipeptidase 4 inhibitors (DPP4i) in the management of diabetic foot. <b>Methods:</b> Literature search was conducted in electronic databases (Google Scholar, Ovid, PubMed, Science Direct, and Springer) and studies were selected for inclusion if they reported the incidence rate of diabetic foot ulcer during DPP4i treatment or evaluated the effect of DPP4i on wound healing. Incidence rates of foot ulcer, amputation and peripheral vascular disease were pooled to achieve overall estimates. Meta-analyses of odds ratios were performed to evaluate the risk of foot ulcer, amputation, and peripheral vascular disease with DPP4i, and to examine the effect of DPP4i treatment on ulcer healing. <b>Results:</b> Ten studies (532354 DPP4i and 2092010 non-DPP4i treated diabetes patients) were included. Incidence rates of foot ulcer, amputation, and peripheral vascular disease were 3.80 [95% confidence interval (CI): 0.22, 7.39], 0.82 [95%CI: 0.60, 1.05], and 22.33 [95%CI: 9.14, 35.53] per 1000 person-years respectively in patients treated with DPP4i and 3.60 [95%CI: 1.77, 5.39], 0.76 [95%CI: 0.58, 0.94], and 20.9 [95%CI: 16.04, 25.81] per 1000 person-years respectively in patients treated with non-DPP4i drugs. Risk of ulcer or amputation with DPP4i was not consistent across studies. Odds of non-healing of ulcer were significantly lower with DPP4i in comparison with controls (odds ratio: 0.27 [95%CI: 0.10, 0.71]; p = 0.008). <b>Conclusion:</b> Incidence rates of diabetic foot and amputation are found to be similar with DPP4i and non-DPP4i drugs. DPP4i improved wound healing of diabetic foot in 3-month randomized trials.</p>","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"1 1","pages":"577-584"},"PeriodicalIF":4.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84573817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob B. Woodard, B. Mirus, Nathan J. Wood, K. Allstadt, Benjamin A. Leshchinsky, Matthew M. Crawford
Abstract. Slope units are terrain partitions bounded by drainage and divide lines. In landslide modeling, including susceptibility modeling and event-specific modeling of landslide occurrence, slope units provide several advantages over gridded units, such as better capturing terrain geometry, improved incorporation of geospatial landslide-occurrence data in different formats (e.g., point and polygon), and better accommodating the varying data accuracy and precision in landslide inventories. However, the use of slope units in regional (> 100 km2) landslide studies remains limited due, in part, to the large computational costs and/or poor reproducibility with current delineation methods. We introduce a computationally efficient algorithm for the parameter-free delineation of slope units that leverages tools from within TauDEM and GRASS, using an R interface. The algorithm uses geomorphic laws to define the appropriate scaling of the slope units representative of hillslope processes, avoiding the often ambiguous determination of slope unit size. We then demonstrate how slope units enable more robust regional-scale landslide susceptibility and event-specific landslide occurrence maps.
摘要斜坡单元是以排水线和分界线为边界的地形分区。在滑坡建模（包括易发性建模和滑坡发生的特定事件建模）中，与网格单元相比，斜坡单元具有若干优势，例如能更好地捕捉地形几何形状，更好地纳入不同格式（如点和多边形）的地理空间滑坡发生数据，以及更好地适应滑坡清单中不同的数据精度和准确性。然而，在区域（大于 100 平方公里）滑坡研究中，斜坡单元的使用仍然有限，部分原因是计算成本高和/或当前划分方法的可重复性差。我们介绍了一种计算效率高的无参数斜坡单元划分算法，该算法利用 TauDEM 和 GRASS 中的工具，并使用 R 接口。该算法利用地貌规律来定义代表山坡过程的斜坡单元的适当比例，避免了通常模棱两可的斜坡单元大小的确定。然后，我们演示了斜坡单元如何实现更强大的区域尺度滑坡易发性和特定事件滑坡发生图。
{"title":"Slope Unit Maker (SUMak): an efficient and parameter-free algorithm for delineating slope units to improve landslide modeling","authors":"Jacob B. Woodard, B. Mirus, Nathan J. Wood, K. Allstadt, Benjamin A. Leshchinsky, Matthew M. Crawford","doi":"10.5194/nhess-24-1-2024","DOIUrl":"https://doi.org/10.5194/nhess-24-1-2024","url":null,"abstract":"Abstract. Slope units are terrain partitions bounded by drainage and divide lines. In landslide modeling, including susceptibility modeling and event-specific modeling of landslide occurrence, slope units provide several advantages over gridded units, such as better capturing terrain geometry, improved incorporation of geospatial landslide-occurrence data in different formats (e.g., point and polygon), and better accommodating the varying data accuracy and precision in landslide inventories. However, the use of slope units in regional (> 100 km2) landslide studies remains limited due, in part, to the large computational costs and/or poor reproducibility with current delineation methods. We introduce a computationally efficient algorithm for the parameter-free delineation of slope units that leverages tools from within TauDEM and GRASS, using an R interface. The algorithm uses geomorphic laws to define the appropriate scaling of the slope units representative of hillslope processes, avoiding the often ambiguous determination of slope unit size. We then demonstrate how slope units enable more robust regional-scale landslide susceptibility and event-specific landslide occurrence maps.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"19 8","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139389370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-22DOI: 10.5194/nhess-23-3895-2023
Chu-En Hsu, K. Serafin, Xiao Yu, C. Hegermiller, J. Warner, M. Olabarrieta
Abstract. Total water levels (TWLs), including the contribution of wind waves, associated with tropical cyclones (TCs) are among the most damaging hazards faced by coastal communities. TC-induced economic losses are expected to increase because of stronger TC intensity, sea level rise, and increased populations along the coasts. TC intensity, translation speed, and distance to the coast affect the magnitude and duration of increased TWLs and wind waves. Under climate change, the proportion of high-intensity TCs is projected to increase globally, whereas the variation pattern of TC translation speed also depends on the ocean basin and latitude. There is an urgent need to improve our understanding of the linkages between TC characteristics and TWL components. In the past few years, hurricanes Matthew (2016), Dorian (2019), and Isaias (2020) propagated over the South Atlantic Bight (SAB) with similar paths but resulted in different coastal impacts. We combined in situ observations and numerical simulations with the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system to analyze the extreme TWLs under the three TCs. Model verification showed that the TWL components were well reproduced by the present model setup. Our results showed that the peak storm surge and the peak wave runup depended mainly on the TC intensity, the distance to the TC eye, and the TC heading direction. A decrease in TC translation speed primarily led to longer exceedance durations of TWLs, which may result in more severe economic losses. Wave-dependent water level components (i.e., wave setup and wave swash) were found to dominate the peak TWL within the near-TC field. Our results also showed that in specific conditions, the prestorm wave runup associated with the TC-induced swell may lead to TWLs higher than at the peak of the storm. This was the case along the SAB during Hurricane Isaias. Isaias's fast TC translation speed and the fact that its swell was not blocked by any islands were the main factors contributing to these peak TWLs ahead of the storm peak.
{"title":"Total water levels along the South Atlantic Bight during three along-shelf propagating tropical cyclones: relative contributions of storm surge and wave runup","authors":"Chu-En Hsu, K. Serafin, Xiao Yu, C. Hegermiller, J. Warner, M. Olabarrieta","doi":"10.5194/nhess-23-3895-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3895-2023","url":null,"abstract":"Abstract. Total water levels (TWLs), including the contribution of wind waves, associated with tropical cyclones (TCs) are among the most damaging hazards faced by coastal communities. TC-induced economic losses are expected to increase because of stronger TC intensity, sea level rise, and increased populations along the coasts. TC intensity, translation speed, and distance to the coast affect the magnitude and duration of increased TWLs and wind waves. Under climate change, the proportion of high-intensity TCs is projected to increase globally, whereas the variation pattern of TC translation speed also depends on the ocean basin and latitude. There is an urgent need to improve our understanding of the linkages between TC characteristics and TWL components. In the past few years, hurricanes Matthew (2016), Dorian (2019), and Isaias (2020) propagated over the South Atlantic Bight (SAB) with similar paths but resulted in different coastal impacts. We combined in situ observations and numerical simulations with the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system to analyze the extreme TWLs under the three TCs. Model verification showed that the TWL components were well reproduced by the present model setup. Our results showed that the peak storm surge and the peak wave runup depended mainly on the TC intensity, the distance to the TC eye, and the TC heading direction. A decrease in TC translation speed primarily led to longer exceedance durations of TWLs, which may result in more severe economic losses. Wave-dependent water level components (i.e., wave setup and wave swash) were found to dominate the peak TWL within the near-TC field. Our results also showed that in specific conditions, the prestorm wave runup associated with the TC-induced swell may lead to TWLs higher than at the peak of the storm. This was the case along the SAB during Hurricane Isaias. Isaias's fast TC translation speed and the fact that its swell was not blocked by any islands were the main factors contributing to these peak TWLs ahead of the storm peak.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"35 23","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138946813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-15DOI: 10.5194/nhess-23-3839-2023
T. Chmielewski, P. Bońkowski
Abstract. The paper deals with wind speeds of extreme wind events in Poland and the descriptions of their effects. Two recent estimations developed by the Institute of Meteorology and Water Management in Warsaw and by Halina Lorenc (a previous co-worker of the institute) are presented here. Their strong and weak points are briefly described. The 37 annual maximum gusts of wind speeds measured at all meteorological stations between 1971 and 2007 are analysed by an extremal probability paper, block-maxima (BM), and peak-over-threshold (OVT) approaches. Based on the measured and estimated wind speeds (taken from existing literature), the authors suggest new estimations for extreme winds that may occur in Poland. Shortly, Poland will construct important structures, such as a central air terminal and (some) nuclear power plants, so knowledge about extreme winds in our country is significant for engineers who will design these structures.
{"title":"Wind as a natural hazard in Poland","authors":"T. Chmielewski, P. Bońkowski","doi":"10.5194/nhess-23-3839-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3839-2023","url":null,"abstract":"Abstract. The paper deals with wind speeds of extreme wind events in Poland and the descriptions of their effects. Two recent estimations developed by the Institute of Meteorology and Water Management in Warsaw and by Halina Lorenc (a previous co-worker of the institute) are presented here. Their strong and weak points are briefly described. The 37 annual maximum gusts of wind speeds measured at all meteorological stations between 1971 and 2007 are analysed by an extremal probability paper, block-maxima (BM), and peak-over-threshold (OVT) approaches. Based on the measured and estimated wind speeds (taken from existing literature), the authors suggest new estimations for extreme winds that may occur in Poland. Shortly, Poland will construct important structures, such as a central air terminal and (some) nuclear power plants, so knowledge about extreme winds in our country is significant for engineers who will design these structures.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"75 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138998816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.5194/nhess-23-3789-2023
Dong Qiu, B. Lv, Yuepeng Cui, Zexiong Zhan
Abstract. The effects of response efficacy and self-efficacy on disaster preparedness have been widely reported. However, most studies only prove their relationship to disaster preparedness in general terms without ascertaining whether they also variously impact the disaster preparedness of diverse vulnerable families (i.e., caring for older and/or disabled adults (COD), caring for a child (CC), and low capacity (LC)). In this study, disaster preparedness is divided into two dependent variables: adequate and minimal preparedness. A quantitative analysis was conducted using 4559 samples drawn from the 2021 National Household Survey to investigate the relationship between response efficacy and self-efficacy with preparedness measures adopted by vulnerable households. Binary logistic regression results indicated that households with vulnerable groups are generally more likely to report lower disaster preparedness. Response efficacy is more critical to LC and COD families, while self-efficacy is more important to LC and CC families. Based on these findings, interventions can be tailored to suit different family types and help vulnerable families better prepare for disasters.
{"title":"The role of response efficacy and self-efficacy in disaster preparedness actions for vulnerable households","authors":"Dong Qiu, B. Lv, Yuepeng Cui, Zexiong Zhan","doi":"10.5194/nhess-23-3789-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3789-2023","url":null,"abstract":"Abstract. The effects of response efficacy and self-efficacy on disaster preparedness have been widely reported. However, most studies only prove their relationship to disaster preparedness in general terms without ascertaining whether they also variously impact the disaster preparedness of diverse vulnerable families (i.e., caring for older and/or disabled adults (COD), caring for a child (CC), and low capacity (LC)). In this study, disaster preparedness is divided into two dependent variables: adequate and minimal preparedness. A quantitative analysis was conducted using 4559 samples drawn from the 2021 National Household Survey to investigate the relationship between response efficacy and self-efficacy with preparedness measures adopted by vulnerable households. Binary logistic regression results indicated that households with vulnerable groups are generally more likely to report lower disaster preparedness. Response efficacy is more critical to LC and COD families, while self-efficacy is more important to LC and CC families. Based on these findings, interventions can be tailored to suit different family types and help vulnerable families better prepare for disasters.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"8 8","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138972051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.5194/nhess-23-3823-2023
Jingyu Wang, Jiwen Fan, Zhe Feng
Abstract. Hail and tornadoes are hazardous weather events responsible for significant property damage and economic loss worldwide. The most devastating occurrences of hail and tornadoes are commonly produced by supercells in the United States. However, these supercells may also grow upscale into mesoscale convective systems (MCSs) or be embedded within them. The relationship between hail and tornado occurrences with MCSs in the long-term climatology has not been thoroughly examined. In this study, radar features associated with MCSs are extracted from a 14-year MCS tracking database across the contiguous United States, and hazard reports are mapped to these MCS features. We investigate the characteristics of hail and tornadoes in relation to MCSs, considering seasonal and regional variabilities. On average, 8 %–17 % of hail events and 17 %–32 % of tornado events are associated with MCSs, depending on the criteria used to define MCSs. The highest total and MCS-associated hazard events occur from March to May, while the highest MCS-associated portion (23 % for hail and 45 % for tornadoes) is observed in winter (December–February) due to the dominance of MCSs caused by strong synoptic forcing. As hailstone size increases, the fraction associated with MCS decreases, but there is an increasing trend for tornado severity from EF0 to EF3 (Enhanced Fujita Scale). Violent tornadoes at EF4 and EF5 associated with MCSs were also observed, which are generated by supercells embedded within MCSs.
{"title":"Climatological occurrences of hail and tornadoes associated with mesoscale convective systems in the United States","authors":"Jingyu Wang, Jiwen Fan, Zhe Feng","doi":"10.5194/nhess-23-3823-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3823-2023","url":null,"abstract":"Abstract. Hail and tornadoes are hazardous weather events responsible for significant property damage and economic loss worldwide. The most devastating occurrences of hail and tornadoes are commonly produced by supercells in the United States. However, these supercells may also grow upscale into mesoscale convective systems (MCSs) or be embedded within them. The relationship between hail and tornado occurrences with MCSs in the long-term climatology has not been thoroughly examined. In this study, radar features associated with MCSs are extracted from a 14-year MCS tracking database across the contiguous United States, and hazard reports are mapped to these MCS features. We investigate the characteristics of hail and tornadoes in relation to MCSs, considering seasonal and regional variabilities. On average, 8 %–17 % of hail events and 17 %–32 % of tornado events are associated with MCSs, depending on the criteria used to define MCSs. The highest total and MCS-associated hazard events occur from March to May, while the highest MCS-associated portion (23 % for hail and 45 % for tornadoes) is observed in winter (December–February) due to the dominance of MCSs caused by strong synoptic forcing. As hailstone size increases, the fraction associated with MCS decreases, but there is an increasing trend for tornado severity from EF0 to EF3 (Enhanced Fujita Scale). Violent tornadoes at EF4 and EF5 associated with MCSs were also observed, which are generated by supercells embedded within MCSs.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"71 4","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139003292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-06DOI: 10.5194/nhess-23-3761-2023
M. Biguenet, E. Chaumillon, P. Sabatier, Antoine Bastien, Emeline Geba, Fabien Arnaud, T. Coulombier, N. Feuillet
Abstract. Low-lying coasts and small islands, such as in the Lesser Antilles, are particularly vulnerable to hurricane-induced marine floods. In September 2017, category 5 Hurricane Irma, with winds up to 360 km h−1, hit the northern Caribbean islands and caused the destruction of 95 % of the structures on Barbuda Island. We investigated the geomorphological impacts and the sedimentological record related to the storm surge of this hurricane in Barbuda's Codrington Lagoon. Following Hurricane Irma, two wide inlets developed across the Codrington sandy barrier. One of these inlets was enlarged and was still open 4 years later. From available data, it seems that this barrier remained continuous for the last 250 years before Hurricane Irma. At a longer timescale, very high-resolution seismic exploration combined with sediment cores sampled in Codrington Lagoon were used to investigate Irma deposits and environmental changes for the last 3700 years. The evolution from a low-energy small and shallow lagoon to the modern wide and high-energy lagoon recorded by the lagoon sediment fill was related to both long-term sea level rise and subsidence. The top of the lagoon fill consists of a thick and extensive sand sheet recording an abrupt increase in energy. Given its location at the top of the cores and its very recent age, supported by short-lived radionuclide data, together with large inlets opening and barrier erosion after Irma that imply a large sand supply to the lagoon, this sand sheet was attributed to Hurricane Irma. From our cores, it appears that this deposit is unique over more than 3700 years. Both the opening of a new inlet and the thick upper sand sheet support the exceptional character of Irma at the scale of centuries to millennia. Our study reinforces the idea that Hurricane Irma was exceptional in terms of intensity and may be associated with global warming.
{"title":"Hurricane Irma: an unprecedented event over the last 3700 years? Geomorphological changes and sedimentological record in Codrington Lagoon, Barbuda","authors":"M. Biguenet, E. Chaumillon, P. Sabatier, Antoine Bastien, Emeline Geba, Fabien Arnaud, T. Coulombier, N. Feuillet","doi":"10.5194/nhess-23-3761-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3761-2023","url":null,"abstract":"Abstract. Low-lying coasts and small islands, such as in the Lesser Antilles, are particularly vulnerable to hurricane-induced marine floods. In September 2017, category 5 Hurricane Irma, with winds up to 360 km h−1, hit the northern Caribbean islands and caused the destruction of 95 % of the structures on Barbuda Island. We investigated the geomorphological impacts and the sedimentological record related to the storm surge of this hurricane in Barbuda's Codrington Lagoon. Following Hurricane Irma, two wide inlets developed across the Codrington sandy barrier. One of these inlets was enlarged and was still open 4 years later. From available data, it seems that this barrier remained continuous for the last 250 years before Hurricane Irma. At a longer timescale, very high-resolution seismic exploration combined with sediment cores sampled in Codrington Lagoon were used to investigate Irma deposits and environmental changes for the last 3700 years. The evolution from a low-energy small and shallow lagoon to the modern wide and high-energy lagoon recorded by the lagoon sediment fill was related to both long-term sea level rise and subsidence. The top of the lagoon fill consists of a thick and extensive sand sheet recording an abrupt increase in energy. Given its location at the top of the cores and its very recent age, supported by short-lived radionuclide data, together with large inlets opening and barrier erosion after Irma that imply a large sand supply to the lagoon, this sand sheet was attributed to Hurricane Irma. From our cores, it appears that this deposit is unique over more than 3700 years. Both the opening of a new inlet and the thick upper sand sheet support the exceptional character of Irma at the scale of centuries to millennia. Our study reinforces the idea that Hurricane Irma was exceptional in terms of intensity and may be associated with global warming.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"68 49","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138594816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-04DOI: 10.5194/nhess-23-3747-2023
R. Jiang, Guoping Zhang, Shudong Wang, Bing Xue, Zhengshuai Xie, Tingzhao Yu, Kuoyin Wang, Jin Ding, Xiaoxiang Zhu
Abstract. A lightning location system consisting of multiple ground-based stations is an effective means of lightning observation. The dataset from CNLDN (China National Lightning Detection Network) in 2016–2022 is employed to analyze the temporal and spatial lightning distributions and the differences between +CG (positive cloud-to-ground lightning) and −CG (negative cloud-to-ground lightning) strokes in China. On the annual scale, lightning activity is most prevalent during the summer months (June, July, and August), accounting for 72.6 % of the year. Spring sees more lightning than autumn, and winter has only a small amount in southeastern coastal areas. During the day, the frequency of lightning peaks at 15:00–17:00 CST (China standard time) and is lowest at 8:00–10:00 CST. For the period with high CG stroke frequency (summer of a year or afternoon of a day), the proportion of +CG strokes and the discharge peak current are relatively small. Winter in a year and morning or midnight in a day correspond to a greater +CG stroke proportion and discharge current. Spatially, low latitudes, undulating terrain, the seaside, and humid surfaces are favorable factors for lightning occurrence. Thus, the southeast coastland has the largest lightning stroke density, while the northwest deserts and basins and the western and northern Tibetan Plateau, with altitudes over 6000 m, have almost no lightning. The proportion of +CG strokes and the peak current are low in the southern region with high density but diverse in other regions. The Tibetan Plateau causes the diversity of lightning activity in China and lays the foundation for studying the impact of surface elevation on lightning. Results indicate that the +CG stroke proportion on the eastern and southern Tibetan Plateau is up to 15 %, larger than the plain regions. The peak current of −CG strokes is positively correlated with altitude, but +CG strokes show a negative correlation, resulting in a large difference in peak current between +CG and −CG on the plain and a small difference on the plateau.
{"title":"Characteristics of cloud-to-ground lightning (CG) and differences between +CG and −CG strokes in China regarding the China National Lightning Detection Network","authors":"R. Jiang, Guoping Zhang, Shudong Wang, Bing Xue, Zhengshuai Xie, Tingzhao Yu, Kuoyin Wang, Jin Ding, Xiaoxiang Zhu","doi":"10.5194/nhess-23-3747-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3747-2023","url":null,"abstract":"Abstract. A lightning location system consisting of multiple ground-based stations is an effective means of lightning observation. The dataset from CNLDN (China National Lightning Detection Network) in 2016–2022 is employed to analyze the temporal and spatial lightning distributions and the differences between +CG (positive cloud-to-ground lightning) and −CG (negative cloud-to-ground lightning) strokes in China. On the annual scale, lightning activity is most prevalent during the summer months (June, July, and August), accounting for 72.6 % of the year. Spring sees more lightning than autumn, and winter has only a small amount in southeastern coastal areas. During the day, the frequency of lightning peaks at 15:00–17:00 CST (China standard time) and is lowest at 8:00–10:00 CST. For the period with high CG stroke frequency (summer of a year or afternoon of a day), the proportion of +CG strokes and the discharge peak current are relatively small. Winter in a year and morning or midnight in a day correspond to a greater +CG stroke proportion and discharge current. Spatially, low latitudes, undulating terrain, the seaside, and humid surfaces are favorable factors for lightning occurrence. Thus, the southeast coastland has the largest lightning stroke density, while the northwest deserts and basins and the western and northern Tibetan Plateau, with altitudes over 6000 m, have almost no lightning. The proportion of +CG strokes and the peak current are low in the southern region with high density but diverse in other regions. The Tibetan Plateau causes the diversity of lightning activity in China and lays the foundation for studying the impact of surface elevation on lightning. Results indicate that the +CG stroke proportion on the eastern and southern Tibetan Plateau is up to 15 %, larger than the plain regions. The peak current of −CG strokes is positively correlated with altitude, but +CG strokes show a negative correlation, resulting in a large difference in peak current between +CG and −CG on the plain and a small difference on the plateau.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"29 11","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138604297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.5194/nhess-23-3723-2023
A. V. van Natijne, T. Bogaard, T. Zieher, J. Pfeiffer, R. Lindenbergh
Abstract. Landslides are one of the major weather-related geohazards. To assess their potential impact and design mitigation solutions, a detailed understanding of the slope processes is required. Landslide modelling is typically based on data-rich geomechanical models. Recently, machine learning has shown promising results in modelling a variety of processes. Furthermore, slope conditions are now also monitored from space, in wide-area repeat surveys from satellites. In the present study we tested if use of machine learning, combined with readily available remote sensing data, allows us to build a deformation nowcasting model. A successful landslide deformation nowcast, based on remote sensing data and machine learning, would demonstrate effective understanding of the slope processes, even in the absence of physical modelling. We tested our methodology on the Vögelsberg, a deep-seated landslide near Innsbruck, Austria. Our results show that the formulation of such a machine learning system is not as straightforward as often hoped for. The primary issue is the freedom of the model compared to the number of acceleration events in the time series available for training, as well as inherent limitations of the standard quality metrics such as the mean squared error. Satellite remote sensing has the potential to provide longer time series, over wide areas. However, although longer time series of deformation and slope conditions are clearly beneficial for machine-learning-based analyses, the present study shows the importance of the training data quality but also that this technique is mostly applicable to the well-monitored, more dynamic deforming landslides.
{"title":"Machine-learning-based nowcasting of the Vögelsberg deep-seated landslide: why predicting slow deformation is not so easy","authors":"A. V. van Natijne, T. Bogaard, T. Zieher, J. Pfeiffer, R. Lindenbergh","doi":"10.5194/nhess-23-3723-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3723-2023","url":null,"abstract":"Abstract. Landslides are one of the major weather-related geohazards. To assess their potential impact and design mitigation solutions, a detailed understanding of the slope processes is required. Landslide modelling is typically based on data-rich geomechanical models. Recently, machine learning has shown promising results in modelling a variety of processes. Furthermore, slope conditions are now also monitored from space, in wide-area repeat surveys from satellites. In the present study we tested if use of machine learning, combined with readily available remote sensing data, allows us to build a deformation nowcasting model. A successful landslide deformation nowcast, based on remote sensing data and machine learning, would demonstrate effective understanding of the slope processes, even in the absence of physical modelling. We tested our methodology on the Vögelsberg, a deep-seated landslide near Innsbruck, Austria. Our results show that the formulation of such a machine learning system is not as straightforward as often hoped for. The primary issue is the freedom of the model compared to the number of acceleration events in the time series available for training, as well as inherent limitations of the standard quality metrics such as the mean squared error. Satellite remote sensing has the potential to provide longer time series, over wide areas. However, although longer time series of deformation and slope conditions are clearly beneficial for machine-learning-based analyses, the present study shows the importance of the training data quality but also that this technique is mostly applicable to the well-monitored, more dynamic deforming landslides.\u0000","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":" 22","pages":""},"PeriodicalIF":4.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138617409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-14DOI: 10.5194/nhess-23-3467-2023
Benedikt Mester, Thomas Vogt, Seth Bryant, Christian Otto, Katja Frieler, Jacob Schewe
Abstract. Extreme weather events, such as tropical cyclones, often trigger population displacement. The frequency and intensity of tropical cyclones are affected by anthropogenic climate change. However, the effect of historical climate change on displacement risk has so far not been quantified. Here, we show how displacement can be partially attributed to climate change using the example of the 2019 Tropical Cyclone Idai in Mozambique. We estimate the population exposed to high water levels following Idai's landfall using a combination of a 2D hydrodynamical storm surge model and a flood depth estimation algorithm to determine inland flood depths from remote sensing images, factual (climate change) and counterfactual (no climate change) mean sea level, and maximum wind speed conditions. Our main estimates indicate that climate change has increased displacement risk from this event by approximately 12 600–14 900 additional displaced persons, corresponding to about 2.7 % to 3.2 % of the observed displacements. The isolated effect of wind speed intensification is double that of sea level rise. These results are subject to important uncertainties related to both data and modeling assumptions, and we perform multiple sensitivity experiments to assess the range of uncertainty where possible. Besides highlighting the significant effects on humanitarian conditions already imparted by climate change, our study provides a blueprint for event-based displacement attribution.
{"title":"Human displacements from Tropical Cyclone Idai attributable to climate change","authors":"Benedikt Mester, Thomas Vogt, Seth Bryant, Christian Otto, Katja Frieler, Jacob Schewe","doi":"10.5194/nhess-23-3467-2023","DOIUrl":"https://doi.org/10.5194/nhess-23-3467-2023","url":null,"abstract":"Abstract. Extreme weather events, such as tropical cyclones, often trigger population displacement. The frequency and intensity of tropical cyclones are affected by anthropogenic climate change. However, the effect of historical climate change on displacement risk has so far not been quantified. Here, we show how displacement can be partially attributed to climate change using the example of the 2019 Tropical Cyclone Idai in Mozambique. We estimate the population exposed to high water levels following Idai's landfall using a combination of a 2D hydrodynamical storm surge model and a flood depth estimation algorithm to determine inland flood depths from remote sensing images, factual (climate change) and counterfactual (no climate change) mean sea level, and maximum wind speed conditions. Our main estimates indicate that climate change has increased displacement risk from this event by approximately 12 600–14 900 additional displaced persons, corresponding to about 2.7 % to 3.2 % of the observed displacements. The isolated effect of wind speed intensification is double that of sea level rise. These results are subject to important uncertainties related to both data and modeling assumptions, and we perform multiple sensitivity experiments to assess the range of uncertainty where possible. Besides highlighting the significant effects on humanitarian conditions already imparted by climate change, our study provides a blueprint for event-based displacement attribution.","PeriodicalId":18922,"journal":{"name":"Natural Hazards and Earth System Sciences","volume":"12 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134954708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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