This paper analyses liquefaction potential in a high seismic region in Bengkulu City, Indonesia. The liquefaction hazard map, derived from the liquefaction potential index using site investigation data and geophysical surveys, is presented. The study begins with collecting site investigation data and measuring geophysical parameters. Peak ground acceleration and potential seismic damage are estimated. Liquefaction potential analysis is based on site investigation data and maximum estimated peak ground acceleration. The integrated map represents the depth-weighted analysis, and the factor of safety, also known as the liquefaction potential index, is discussed. Results indicate the predominance of sandy soils in the study area, prone to liquefaction. Coastal and river channel areas, characterised by loose sandy soils, exhibit high liquefaction potential. The study area is also expected to experience strong motion, potentially reaching intensity level IX on the Modified Mercalli Intensity scale, indicating liquefaction susceptibility during strong earthquakes. Overall, the study results offer recommendations for local government spatial planning development.

We present a multidisciplinary research aimed at quantifying the conditional probabilities for hazards associated with pyroclastic avalanches at Etna, which combines physical and numerical modeling of granular avalanches and probabilistic analysis. Pyroclastic avalanches are modeled using the depth-averaged model IMEX-SfloW2D, which is able to simulate the transient propagation and emplacement of granular flows generated by the collapse of a prescribed volume of granular material. Preliminary sensitivity analysis allowed us to identify the main controlling parameters of the dynamics, i.e. the total avalanche mass, the initial position of the collapsing granular mass (and the associated terrain morphology), the initial avalanche velocity, and the two rheological parameters which determine the mechanical properties of the flow. While the first two parameters can be considered as scenario parameters in the definition of the hazards, the initial velocity and the rheological parameters need to be calibrated. We therefore adopted a methodology for the statistical calibration of the physical model parameters based on field observations. We used data from the pyroclastic avalanche that occurred on February 10, 2022 at Etna, for which we had an accurate mapping of the deposit and some estimates of the total mass and the initial volume. We then run a preliminary ensemble of numerical simulations, with fixed initial volume and position, to calibrate the other input parameters. Based on the accuracy of the matching of the simulated and observed deposits (measured by the Jaccard Index), we extracted from the simulation ensemble a subsample of equally probable combinations of initial velocities and rheological parameters. We then built an ensemble of model input parameters, with varying (i) avalanche volumes, (ii) initial positions, (iii) velocity, and (iv) rheological coefficients. The initial volume range was chosen within the range of observed pyroclastic avalanches at Etna (i.e., between 0.1 and 3 x 106 m3), using a prescribed probability distribution extracted from the literature data. The initial positions have been chosen on the flanks of the South East Crater of Etna, with homogeneous spatial distribution. The initial velocity and the rheological coefficients were chosen from the subsample created with the calibration. Finally, a semi-automatic procedure (digital workflow) running the Monte Carlo simulation allowed us to produce the first probabilistic map of pyroclastic avalanche invasion at Etna. Such a map, conditional to the occurrence of a pyroclastic avalanche event, can be used to identify the hazardous areas of the volcano and to plan mitigation measures.

The increasing frequency of earthquakes in Kuwait raises concerns regarding soil liquefaction. Currently, there is no soil liquefaction potential map for Kuwait, even for soil profiles along coastal shores, where the groundwater table is near the surface. To address this gap, investigations and assessments were carried out and ArcMap 10.8 was used to establish five soil liquefaction hazard potential maps for Kuwait for different earthquake scenarios based on available borehole logs. The popular methods for evaluating soil liquefaction hazard are the simplified approach proposed in the National Center for Earthquake Engineering Research workshop, which is based on standard penetration tests (for determining the safety factor), and Luna and Frost's (1998) method to assess the liquefaction potential index. Notably, standard penetration test blows were used to investigate the variations in the soil relative density below the surface, describe seismic sources, and estimate peak ground accelerations (calculated using Cornell's equation and verified using ground-motion models). Southern Kuwait was highly vulnerable to soil liquefaction potential (local earthquake moment magnitude of 5.5); this was confirmed by the documented structural damage. Such maps can be used to identify the areas vulnerable to soil liquefaction and limit the risk to infrastructure.

Flash floods are a major threat to life and properties in arid regions. In recent decades, Egypt has experienced severe flash floods that have caused significant damage across the country, including the Red Sea region. The aim of this study is to map the flood hazards in flood-prone areas along the Red Sea region using a Geographic Information System (GIS)-based morphometric analysis approach. To evaluate the flood hazard degree, the adopted methodology considers various morphometric parameters such as basin area, slope, sinuosity index, shape factor, drainage intensity, circularity ratio, and curve number. GIS techniques were employed to delineate the watershed and the drainage network. The delineated watershed was used together with the digitized maps of soil and land use types to estimate the curve number and the morphometric parameters for each subbasin. The flood hazard degrees are calculated based on the considered morphometric parameters and distinguished based on a five-degree scale ranging from very low to very high. Results indicate that 47% of the study area has a very high flood hazard degree. Furthermore, morphometric analysis results align with the runoff results simulated by a hydrological model, where, for example, basins with a high to very high hazard degree exhibited high runoff. This suggests the influence of physical characteristics on the hydrological behavior of the watershed and further validates the morphometric analysis presented in this work. The results presented here can help policy planners and decision-makers develop appropriate measures to mitigate flash floods and achieve sustainable development in arid regions.