Challenges of groundwater pollution and management in transboundary basins at the African scale

We address the significant knowledge gap for groundwater pollution in Africa methods by assessing groundwater pollution risk at the African scale. To do so, we compiled the most recent continental-scale information on soil, land use, geology, hydrogeology, and topography in a Geographical Information System at the resolution of 15 × 15 km and the 1:60 000 000 scale. We produced a vulnerability map by using the generic DRASTIC vulnerability indicator. This map revealed that groundwater is highly vulnerable in Central and West Africa groundwater basins, where the water table is shallow. In addition, very low vulnerability classes are found in the large sedimentary basins of Africa deserts where groundwater is situated in very deep aquifers. The generic groundwater pollution risk map is obtained by overlaying the DRASTIC vulnerability indicator with current land use. The northern, central, and western parts of the African continent are dominated by high vulnerability classes and very strongly related to water table depths and the development of agricultural activities. Given the availability of data, we concentrate first on nitrate vulnerability mapping. To this end, groundwater nitrate contamination data are compiled in literature using meta-analysis technic and used to calibrate as well linear and nonlinear statistical models; the latter performing much better as compared to simple linear statistical models. This study will help to raise awareness of the manager's International Basin Authorities or Transboundary Basin Organizations in Africa and in particular on transboundary groundwater pollution issues.

Comprehensive seismic risk assessment map of South Korea developed using seismic, geotechnical, and social vulnerability indicators

At present, because it is not possible to predict earthquakes, disaster preparedness is vital for the reduction of damages. The awareness about earthquakes has substantially increased after the occurrence of two >M L 5 events in 2016 and 2017 in South Korea. This study presents the seismic risk assessment conducted for the entire country of South Korea. This assessment was performed using seismic, geotechnical, and social vulnerability indicators. The seismic vulnerability indicator was estimated using a probabilistic seismic hazard and fault-line density map that are directly related to the occurrence of earthquakes. The geotechnical vulnerability indicator was derived using bedrock depth data and extrapolation of digital elevation model data through geostatistical techniques. The seismic and geotechnical indicators were integrated based on the bedrock depth distribution. The social vulnerability indicator considered the distribution of relevant parameters such as vulnerable people, old houses, and road information. These statistical data without spatial continuity were incorporated into a map using principal component analysis. A five-grade classification of risks presented by the seismic and geotechnical vulnerability map and the social vulnerability index map was developed to facilitate simultaneous assessment. A risk matrix was applied to the two maps to produce a comprehensive seismic risk assessment map of South Korea, in which the southeastern and northwestern regions of South Korea present a high seismic risk. The results of this study will serve toward seismic risk management and minimize seismic disaster damages in South Korea.

Evaluation Indicator of Regional Energy Vulnerability to Climate Change - Spatial and Temporal Analysis

Climate change might affect energy production and therefore the energy security of a country or region. This vulnerability situation may affect Renewable Energy Sources (RES) such as hydroelectric and has consequences on effective energy transition. Since the transition to RES is a key for decarbonizing the economy in line with the Paris Agreement this situation is critical for many countries in which their energy systems are linked to resources strongly affected by climate. The aim of this study is to purpose a vulnerability indicator (VI) to evaluate the electric energy vulnerability of an on-grid system to climate change at national and regional level taking as base the case of study of Colombia, a country with a system based on 70% RES. VI is computed with different variables that may be related to climate change, the energy matrix, and vulnerability. Principal Component Analysis (PCA) was used to select the variables involved in the VI calculation. The VI was calculated for the whole country and the 32 departments (states) showing that the regions with the larger vulnerability correspond to the more energy demanding regions. These vulnerable regions to climate change are more than 50% of the maximum possible vulnerability, meanwhile, the vulnerability of the whole country was estimated as 43%. The analysis was developed for the current situation of Colombia in which there are two regions: interconnected (SIN) and not-interconnected (ZNI) areas.

Assessment of Moscow population vulnerability to natural and technogenic hazards

This article introduced an assessment of the Moscow population vulnerability to natural and man-made hazards, taking into account the actual population size and its movement within different time cycles (daily and weekly-seasonal). The use of alternative information sources, allowing to obtain more detailed information about the state of socio-geographical systems, correlates with modern international approaches and corresponds to global trends in the methodological approaches modification to solve a wide range of issues. In this work, in addition to official statistical sources, we used data from mobile operators, which make it possible to characterize the localization of subscribers at a certain point in time with the maximum degree of reliability. This made it possible to significantly correct and clarify the currently existing ideas about the distribution of the population over the Moscow city territory. A series of maps has been created that demonstrate population density as a key vulnerability indicator in the context of Moscow municipalities according to Rosstat data and mobile operators information (at the beginning of 2020). In order to identify the discrepancy between the data on the statistically recorded and real existing population, an existing population assessment in the areas of potential technogenic impact of Moscow potentially dangerous enterprises was carried out. As a result of the study, it was shown that in terms of the natural hazard level, urban space differentiation is less pronounced than in terms of the technogenic hazard level. Technogenic hazards endanger the life and safety of not only the traditionally environmentally unfavorable city parts but also a number of prosperous and prestigious districts. It was found that the number of citizens in the zones of the most dangerous enterprises potential impact varies widely throughout the year—from 0.6 to 1.3 million people (on average it is 1 / 10 from all capital residents). These calculated results are much higher than official documents shows.

MACROECONOMIC PERSPECTIVE ON CONSTRUCTING FINANCIAL VULNERABILITY INDICATOR IN CHINA

This paper attempts to develop a financial vulnerability indicator for China as a barometer for the state of financial vulnerability in the Chinese financial market, possibly for real-time application. Twelve variables from different sectors are utilised to extract a common vulnerability component using a dynamic approximate factor model. Through the implementation of a Markovswitching Bayesian vector autoregression (MSBVAR) model, the empirical results indicate that a high-vulnerability episode is associated with substantially lower economic activity, but a low-vulnerability episode does not incur substantial changes in economic activity. Notably, the constructed indicator can serve as a real-time early warning system to signify vulnerabilities in the Chinese financial market.

SEISMIC VULNERABILITY ASSESSMENT OF HISTORICAL URBAN CENTRES: THE CASE STUDY OF CAMPI ALTO DI NORCIA, ITALY

Seismic damage assessment is a valuable opportunity to evaluate the accuracy of vulnerability and risk methodologies applied to historic masonry buildings, giving the possibility of enhancing and optimizing mitigation and retrofit strategies. Vulnerability index methodologies are flexible and powerful tools for the seismic assessment at urban scale, able to provide a first screening of the critical issues present in masonry structural aggregates. The different structural features of the buildings, directly and indirectly influencing their structural behaviour, are measured through different weights and scores finally achieving a vulnerability indicator. In the present paper, four different vulnerability index methodologies are applied to the medieval city of Campi Alto di Norcia in Valnerina, Umbria, recently stroke by the 2016 Central Italy earthquakes. The accuracy of the adopted Iv methods is assessed based on the real damages’ analysis performed in the surrounding area, comparing results achieved from the application of considered methodologies to direct in-situ observations. Data collected during the 2016 post-earthquake damage surveys and usability assessment, together with the external visual inspections carried out and with the information coming from retrofitting design interventions performed between 1979 and 1997, are used.

Financial Vulnerability and Economic Dynamics in Malaysia

This study attempts to develop a financial vulnerability indicator serving as a composite indicator for the state of financial vulnerability. The indicator was constructed from 10 variables of macroeconomic, financial and property market by extracting a common vulnerability component through the dynamic approximate factor model. On the feedback and amplification effects, the outcome revealed that financial vulnerability shock catalysed significant negative effects on economic activity in a high-vulnerability regime, while the impact was negligible in periods of low vulnerability. This study highlighted the usefulness of composite indicators as an early warning mechanism to gauge vulnerabilities in the Malaysian financial system.