A systematic exploration of satellite radar coherence methods for rapid landslide detection Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-3197-2020 25 December 2020 Satellite radar could provide information on landslide locations within days of an earthquake or rainfall event anywhere on Earth, but until now there has been a lack of systematic testing of possible radar methods, and most methods have been demonstrated using a single case study event and data from a single satellite sensor. Here we test five methods on four events, demonstrating their wide applicability and making recommendations on when different methods should be applied in the future. Read more
Storm tide amplification and habitat changes due to urbanization of a lagoonal estuary Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2415-2020 13 October 2020 The geometry of estuaries is often altered through dredging to make room for ships and with extensive landfill over wetlands to enable development. Here, we use historical maps to help create computational models of seawater flow around and into a lagoonal bay of New York City for the 1880s and 2010s. Our results show that these past man-made changes cause higher coastal storm tides and that they result specifically from deeper depths, expanded inlet width, and landfill. Read more
Fire Weather Index: the skill provided by the European Centre for Medium-Range Weather Forecasts ensemble prediction system Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2365-2020 22 September 2020 Forecasting of daily fire weather indices driven by the ECMWF ensemble prediction system is shown to have a good skill up to 10 d ahead in predicting flammable conditions in most regions of the world. The availability of these forecasts through the Copernicus Emergency Management Service can extend early warnings by up to 1–2 weeks, allowing for greater proactive coordination of resource-sharing and mobilization within and across countries. Read more
Anthropogenic climate change and glacier lake outburst flood risk: local and global drivers and responsibilities for the case of lake Palcacocha, Peru Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2175-2020 27 August 2020 There is increasing interest and need to analyze the contribution of anthropogenic climate change to negative impacts of climate change. We study the case of glacial lake Palcacocha in Peru, which poses a significant flood risk to the city of Huaraz. We found that greenhouse gas emissions; strong urbanization processes without appropriate land use planning; and social, cultural, political, and institutional factors all contribute to the existing flood risk. Read more
Invited perspectives: The volcanoes of Naples: how can the highest volcanic risk in the world be effectively mitigated? Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2037-2020 4 August 2020 This paper starts by showing the present low performance of eruption forecasting and then addresses the problem of effectively mitigating the highest volcanic risk in the world, represented by the Naples area (southern Italy). The problem is considered in a highly multidisciplinary way, taking into account the main economic, sociological and urban planning issues. Our study gives precise guidelines to assessing and managing volcanic risk in any densely urbanised area. Read more
Spatial database and website for reservoir-triggered seismicity in Brazil Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2001-2020 30 July 2020 One of the biggest challenges in studying reservoir-triggered seismicity (RTS) is to identify factors that can trigger seismicity. A spatial database and a web viewer were created, gathering the data pertinent to the RTS study. Results were obtained in processing these data; for example, the occurrence of RTS increases with the height of the dam, the minimum limiting volume value is 1 × 10 −4 km 3 for occurrence of RTS, and for geology no correlations were found, among other results. Read more
Coastal impacts of Storm Gloria (January 2020) over the north-western Mediterranean Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1955-2020 28 July 2020 Storm Gloria hit the Mediterranean Spanish coastlines between 20 and 23 January 2020, causing severe damages such as flooding of the Ebro River delta. We evaluate its coastal impacts with a numerical simulation of the wind waves and the accumulated ocean water along the coastline (storm surge). The storm surge that reached values up to 1 m was mainly driven by the wind that also generated wind waves up to 8 m in height. We also determine the extent of the Ebro Delta flooded by marine water. Read more
Snow avalanche detection and mapping in multitemporal and multiorbital radar images from TerraSAR-X and Sentinel-1 Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1783-2020 2 July 2020 To assess snow avalanche mapping with radar satellites in Switzerland, we compare 2 m resolution TerraSAR-X images, 10 m resolution Sentinel-1 images, and optical 1.5 m resolution SPOT-6 images. We found that radar satellites provide a valuable option to map at least larger avalanches, though avalanches are mapped only partially. By combining multiple orbits and polarizations from S1, we achieved mapping results of quality almost comparable to single high-resolution TerraSAR-X images. Read more
Induced seismicity risk analysis of the hydraulic stimulation of a geothermal well on Geldinganes, Iceland Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1573-2020 16 June 2020 This study presents a first-of-its-kind pre-drilling probabilistic induced seismic risk analysis for the Geldinganes (Iceland) deep-hydraulic stimulation. The results of the assessment indicate that the individual risk within a radius of 2 km around the injection point is below the safety limits. However, the analysis is affected by a large variability due to the presence of pre-drilling deep uncertainties. This suggests the need for online risk updating during the stimulation. Read more
Present and future changes in winter climate indices relevant for access disruptions in Troms, northern Norway Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1847-2020 9 June 2020 We have studied changes in winter weather known to trigger road closures and isolation of small seaside communities in northern Norway. We find that snow amounts and heavy snowfall events have increased in the past, while future projections for 2040–2100 show a decrease in snow-related indices. Events of heavy water supply and zero crossings are expected to increase. Our results imply fewer dry-snow-related access disruptions in the future, while wet-snow avalanches and slushflows may increase. Read more
