Natural Hazards and Earth System Sciences

Probabilistic Flood Inundation Mapping through Copula Bayesian Multi-Modelling of Precipitation Products
Francisco Javier Gomez, Keighobad Jafarzadegan, Hamed Moftakhari, and Hamid Moradkhani
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-26,2024
Preprint under review for NHESS (discussion: open, 1 comment)
This study utilizes the Global Copula Bayesian Model Averaging technique for accurate and reliable flood modeling, especially in coastal regions. By integrating multiple precipitation datasets within this framework, we can effectively address sources of error in each dataset, leading to the generation of probabilistic flood maps. The creation of these probabilistic maps is essential for disaster preparedness and mitigation in densely populated areas susceptible to extreme weather events.

An Efficient Method to Simulate Wildfire Propagation Using Irregular Grids
Conor Hackett, Rafael de Andrade Moral, Gourav Mishra, Tim McCarthy, and Charles Markham
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-27,2024
Preprint under review for NHESS (discussion: open, 3 comments)
This paper reviews existing wildfire propagation models and a comparison of different grid types including random grids to simulate wildfires. This paper finds that irregular grids simulate wildfires more efficiently than continuous models while still retaining a reasonable level of similarity. It also shows that irregular grids tend to retain greater similarity to continuous models than regular grids at the cost of slightly longer computational times.

Towards a dynamic earthquake risk framework for Switzerland
Maren Böse, Laurentiu Danciu, Athanasios Papadopoulos, John Clinton, Carlo Cauzzi, Irina Dallo, Leila Mizrahi, Tobias Diehl, Paolo Bergamo, Yves Reuland, Andreas Fichtner, Philippe Roth, Florian Haslinger, Frédérick Massin, Nadja Valenzuela, Nikola Blagojević, Lukas Bodenmann, Eleni Chatzi, Donat Fäh, Franziska Glueer, Marta Han, Lukas Heiniger, Paulina Janusz, Dario Jozinović, Philipp Kästli, Federica Lanza, Timothy Lee, Panagiotis Martakis, Michèle Marti, Men-Andrin Meier, Banu Mena Cabrera, Maria Mesimeri, Anne Obermann, Pilar Sanchez-Pastor, Luca Scarabello, Nicolas Schmid, Anastasiia Shynkarenko, Bozidar Stojadinović, Domenico Giardini, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 583–607, https://doi.org/10.5194/nhess-24-583-2024, 2024
Seismic hazard and risk are time dependent as seismicity is clustered and exposure can change rapidly. We are developing an interdisciplinary dynamic earthquake risk framework for advancing earthquake risk mitigation in Switzerland. This includes various earthquake risk products and services, such as operational earthquake forecasting and early warning. Standardisation and harmonisation into seamless solutions that access the same databases, workflows, and software are a crucial component.

Assessing LISFLOOD-FP with the next-generation digital elevation model FABDEM using household survey and remote sensing data in the Central Highlands of Vietnam
Laurence Hawker, Jeffrey Neal, James Savage, Thomas Kirkpatrick, Rachel Lord, Yanos Zylberberg, Andre Groeger, Truong Dang Thuy, Sean Fox, Felix Agyemang, and Pham Khanh Nam
Nat. Hazards Earth Syst. Sci., 24, 539–566, https://doi.org/10.5194/nhess-24-539-2024, 2024
We present a global flood model built using a new terrain data set and evaluated in the Central Highlands of Vietnam.

Evaluating pySTEPS optical flow algorithms for convection nowcasting over the Maritime Continent using satellite data
Joseph Smith, Cathryn Birch, John Marsham, Simon Peatman, Massimo Bollasina, and George Pankiewicz
Nat. Hazards Earth Syst. Sci., 24, 567–582, https://doi.org/10.5194/nhess-24-567-2024, 2024
Nowcasting uses observations to make predictions of the atmosphere on short timescales and is particularly applicable to the Maritime Continent, where storms rapidly develop and cause natural disasters. This paper evaluates probabilistic and deterministic satellite nowcasting algorithms over the Maritime Continent. We show that the probabilistic approach is most skilful at small scales (~ 60 km), whereas the deterministic approach is most skilful at larger scales (~ 200 km).

Converging Human Intelligence with AI Systems to Advance Flood Evacuation Decision Making
Rishav Karanjit, Vidya Samadi, Amanda Hughes, Pamela Murray-Tuite, and Keri Stephens
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-25,2024
Preprint under review for NHESS (discussion: open, 0 comments)
This research paper focused on creating a new paradigm for flood evacuation decisions – so-called human-AI Convergence (HAC) system. A Natural Language Processing (NLP) method was used to mine and filter human data from X posts that were deemed relevant to flooding. The human data along with a river hydraulic model and AI algorithms were integrated into an evacuation re-routing algorithm to forecast flood depth and define evacuation decisions.

Investigation of historical severe storms and storm tides in the German Bight with century reanalysis data
Elke Magda Inge Meyer and Lidia Gaslikova
Nat. Hazards Earth Syst. Sci., 24, 481–499, https://doi.org/10.5194/nhess-24-481-2024, 2024
Storm tides for eight extreme historical storms in the German Bight are modelled using sets of slightly varying atmospheric conditions from the century reanalyses. Comparisons with the water level observations from the gauges Norderney, Cuxhaven and Husum show that single members of the reanalyses are suitable for the reconstruction of extreme storms. Storms with more northerly tracks show less variability within a set and have more potential for accurate reconstruction of extreme water levels.

CRHyME (Climatic Rainfall Hydrogeological Modelling Experiment): a new model for geo-hydrological hazard assessment at the basin scale
Andrea Abbate, Leonardo Mancusi, Francesco Apadula, Antonella Frigerio, Monica Papini, and Laura Longoni
Nat. Hazards Earth Syst. Sci., 24, 501–537, https://doi.org/10.5194/nhess-24-501-2024, 2024
CRHyME (Climatic Rainfall Hydrogeological Modelling Experiment) is a new physically based and spatially distributed rainfall-runoff model. The main novelties consist of reproducing rainfall-induced geo-hydrological hazards such as shallow landslide, debris flow and watershed erosion through a multi-hazard approach. CRHyME was written in Python, works at a high spatial and temporal resolution, and is a tool suitable for quantifying extreme rainfall consequences at the basin scale.

Numerical-model-derived intensity–duration thresholds for early warning of rainfall-induced debris flows in a Himalayan catchment
Sudhanshu Dixit, Srikrishnan Siva Subramanian, Piyush Srivastava, Ali P. Yunus, Tapas Ranjan Martha, and Sumit Sen
Nat. Hazards Earth Syst. Sci., 24, 465–480, https://doi.org/10.5194/nhess-24-465-2024, 2024
Rainfall intensity–duration (ID) thresholds can aid in the prediction of natural hazards. Large-scale sediment disasters like landslides, debris flows, and flash floods happen frequently in the Himalayas because of their propensity for intense precipitation events. We provide a new framework that combines the Weather Research and Forecasting (WRF) model with a regionally distributed numerical model for debris flows to analyse and predict intense rainfall-induced landslides in the Himalayas.

The role of citizen science to assess the spatiotemporal pattern of rainfall events in urban areas: a case study in the city of Genoa, Italy
Nicola Loglisci, Giorgio Boni, Arianna Cauteruccio, Francesco Faccini, Massimo Milelli, Guido Paliaga, and Antonio Parodi
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-24,2024
Preprint under review for NHESS (discussion: open, 1 comment)
This research analyzes the meteo-hydrological features of August 27th and 28th 2023 event occurred in Genoa city. Rainfall observations were taken using either official or rain gauge networks based on citizen science. The combined analysis highlights a spatial variability of the precipitations, which cannot be captured by the current spatial density of the authoritative stations. Results show that at minimal distances the variations in cumulated rainfall over sub-hourly duration are significant.

Improving the fire weather index system for peatlands using peat-specific hydrological input data
Jonas Mortelmans, Anne Felsberg, Gabriëlle J. M. De Lannoy, Sander Veraverbeke, Robert D. Field, Niels Andela, and Michel Bechtold
Nat. Hazards Earth Syst. Sci., 24, 445–464, https://doi.org/10.5194/nhess-24-445-2024, 2024
With global warming increasing the frequency and intensity of wildfires in the boreal region, accurate risk assessments are becoming more crucial than ever before. The Canadian Fire Weather Index (FWI) is a renowned system, yet its effectiveness in peatlands, where hydrology plays a key role, is limited. By incorporating groundwater data from numerical models and satellite observations, our modified FWI improves the accuracy of fire danger predictions, especially over summer.

Understanding flow characteristics from tsunami deposits at Odaka, Joban Coast, using a deep neural network (DNN) inverse model
Rimali Mitra, Hajime Naruse, and Tomoya Abe
Nat. Hazards Earth Syst. Sci., 24, 429–444, https://doi.org/10.5194/nhess-24-429-2024, 2024
This study estimates the behavior of the 2011 Tohoku-oki tsunami from its deposit distributed in the Joban coastal area. In this study, the flow characteristics of the tsunami were reconstructed using the DNN (deep neural network) inverse model, suggesting that the tsunami inundation occurred in the very high-velocity condition.

Climate change impacts on regional fire weather in heterogeneous landscapes of central Europe
Julia Miller, Andrea Böhnisch, Ralf Ludwig, and Manuela I. Brunner
Nat. Hazards Earth Syst. Sci., 24, 411–428, https://doi.org/10.5194/nhess-24-411-2024, 2024
We assess the impacts of climate change on fire danger for 1980–2099 in different landscapes of central Europe, using the Canadian Forest Fire Weather Index (FWI) as a fire danger indicator. We find that today's 100-year FWI event will occur every 30 years by 2050 and every 10 years by 2099. High fire danger (FWI > 21.3) becomes the mean condition by 2099 under an RCP8.5 scenario. This study highlights the potential for severe fire events in central Europe from a meteorological perspective.

Spring water anomalies before two consecutive earthquakes (Mw 7.7 and Mw 7.6) in Kahramanmaraş (Türkiye) on 6 February 2023
Sedat İnan, Hasan Çetin, and Nurettin Yakupoğlu
Nat. Hazards Earth Syst. Sci., 24, 397–409, https://doi.org/10.5194/nhess-24-397-2024, 2024
Two devastating earthquakes, Mw 7.7 and Mw 7.6, occurred in Türkiye on 6 February 2023. We obtained commercially bottled waters from two springs, 100 km from the epicenter of Mw 7.7. Samples of the first spring emanating from fault zone in hard rocks showed positive anomalies in major ions lasting for 6 months before the earthquake. Samples from the second spring accumulated in an alluvium deposit showed no anomalies. We show that pre-earthquake anomalies are geologically site-dependent.

Water depth estimate and flood extent enhancement for satellite-based inundation maps
Andrea Betterle and Peter Salamon
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-22,2024
Preprint under review for NHESS (discussion: open, 1 comment)
The study proposes a new framework, named FLEXTH, to estimate flood water depths and improve satellite-based flood monitoring using topographical data. FLEXTH aims to reduce the impact of floods and is readily available as a computer code, offering a practical and scalable solution for estimating flood depths quickly and systematically over large areas. The methodology can reduce the impacts of floods and enhance emergency response efforts, particularly where resources are limited.

A regional-scale approach to assessing non-residential building, transportation and cropland exposure in Central Asia
Chiara Scaini, Alberto Tamaro, Baurzhan Adilkhan, Satbek Sarzhanov, Zukhritdin Ergashev, Ruslan Umaraliev, Mustafo Safarov, Vladimir Belikov, Japar Karayev, and Ettore Fagà
Nat. Hazards Earth Syst. Sci., 24, 355–373, https://doi.org/10.5194/nhess-24-355-2024, 2024
Central Asia is prone to multiple hazards such as floods, landslides and earthquakes, which can affect a wide range of assets at risk. We develop the first regionally consistent database of assets at risk for non-residential buildings, transportation and croplands in Central Asia. The database combines global and regional data sources and country-based information and supports the development of regional-scale disaster risk reduction strategies for the Central Asia region.

Current and future rainfall-driven flood risk from hurricanes in Puerto Rico under 1.5 and 2 °C climate change
Leanne Archer, Jeffrey Neal, Paul Bates, Emily Vosper, Dereka Carroll, Jeison Sosa, and Daniel Mitchell
Nat. Hazards Earth Syst. Sci., 24, 375–396, https://doi.org/10.5194/nhess-24-375-2024, 2024
We model hurricane-rainfall-driven flooding to assess how the number of people exposed to flooding changes in Puerto Rico under the 1.5 and 2 °C Paris Agreement goals. Our analysis suggests 8 %–10 % of the population is currently exposed to flooding on average every 5 years, increasing by 2 %–15 % and 1 %–20 % at 1.5 and 2 °C. This has implications for adaptation to more extreme flooding in Puerto Rico and demonstrates that 1.5 °C climate change carries a significant increase in risk.

Modelling hazards impacting the flow regime in the Hranice Karst due to the proposed Skalička Dam
Miroslav Spano and Jaromir Riha
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-21,2024
Preprint under review for NHESS (discussion: open, 0 comments)
Our study examines how building the Skalička Dam near the Hranice Karst affects local groundwater. We used advanced modeling to analyze two dam layouts: lateral and through-flow reservoirs. Results show the through-flow variant significantly alters water levels and mineral water discharge, while the lateral layout has less impact.

High-resolution projections of ambient heat for major European cities using different heat metrics
Clemens Schwingshackl, Anne Sophie Daloz, Carley Iles, Kristin Aunan, and Jana Sillmann
Nat. Hazards Earth Syst. Sci., 24, 331–354, https://doi.org/10.5194/nhess-24-331-2024, 2024
Ambient heat in European cities will substantially increase under global warming, as projected by three heat metrics calculated from high-resolution climate model simulations. While the heat metrics consistently project high levels of ambient heat for several cities, in other cities the projected heat levels vary considerably across the three heat metrics. Using complementary heat metrics for projections of ambient heat is thus important for assessments of future risks from heat stress.

Characteristics of spatial and temporal distribution of heavy rainfall and surface runoff generating process in the mountainous areas of northern China
Hui Yang, Xianglong Hou, and Jiansheng Cao
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-8,2024
Preprint under review for NHESS (discussion: open, 0 comments)
For the last decade, a significant upward trend in the frequency of moderate and heavy rainfall events. The spatial variability of rainfall in the Taihang Mountain and the influence of elevation are both smaller when the rainfall during 24 h is lower than 50 mm. For runoff generation under saturated condition, the contribution of rainfall was only 58.17 %. While when the runoff coefficient was greater than 0.5, the surface runoff generating processes were entirely determined by rainfall.