Papers by Keyword: Vulnerability

Abstract: Population increment, and agricultural sector expansion in West Limboto, Gorontalo Regency, Indonesia, affect waste or pollutant increase. The community uses shallow groundwater as the main water source. Since shallow groundwater is vulnerable to pollution due to its depth and community activity, this study aims to identify its vulnerability in West Limboto. It was identified using the Groundwater Confinement, Overlying Strata, and Depth to Groundwater (GOD) Method. Those are also the parameters to be considered. The first parameter needs the aquifer-type data; the more unconfined the aquifer, the higher the index value. The second parameter needs the lithology data covering the stratigraphic aquifer, which is the high permeability lithology will have a higher index value. In comparison, the third parameter needs groundwater table data, which is the nearest to the ground surface, the higher the index value. The analysis shows that the Groundwater Vulnerability Index in the southern part of the study area is 0.5 – 0.7. It means that the aquifer is highly vulnerable to many pollutants. While at the middle to the northern part of the study area have an index of groundwater vulnerability in the range of 0.1 – 0.3, which means that the aquifer is vulnerable to conservative pollutants only. Therefore, the groundwater vulnerability of the study area was classified into 2 classes, the high index was in the southern part, and the low index was in the middle to the northern part of the study area.

Abstract: The building envelope is particularly vulnerable to natural hazards, and it requires new solutions to combine the need for adaptation with the need to mitigate natural hazards. As global temperatures rise, extreme weather events become more frequent, and urban heat islands form, innovative solutions are crucial to mitigate damage and improve building performance. This article aims to identify characteristics of building envelope elements to reduce damage related to the effects of a set of natural hazards of interest, i.e., meteorological and seismic events. The article begins by identifying and quantifying the natural hazards that primarily affect building envelopes. It then examines the impact of these hazards on various envelope elements. The results are a list of performance-based interventions to reduce the vulnerability of envelope technical elements against the hazards of interest. This study offers preliminary results from a broader analysis aimed at quantifying risks to urban environments due to vulnerable building envelope elements. It calls for a reassessment of the typological and performance characteristics of building envelopes to better withstand natural hazards.

Abstract: The current study presents vulnerability and a reliability-mechanical approach which focuses on evaluating the seismic performance of reinforced concrete structures to determine the probability of failure. In this case, the performance function reflecting the non-linear behavior of the structure is modeled by a response surface to establish an analytical relationship between the random variables (strength of concrete and yield strength of steel) and mechanical responses of the structure (inter-floor displacement) obtained by the pushover results of finite element simulations. The push over analysis is executed by software SAP2000. The results acquired prove that properly designed frames will perform well under seismic loads. It is a comparative study of the behavior of the existing structure before and after reinforcement using the pushover method. The coupling indirect mechanical reliability by response surface avoids prohibitive calculation times. Finally, results of the proposed approach are compared with Monte Carlo Simulation. The comparative study shows that the structure is more reliable after the introduction of new shear walls.

Abstract: The increase of atmospheric greenhouse gases results in climate changes which cause the rise of sea level and an increased frequency of extreme climatic events including intense storms, heavy rainfall and droughts. There is a lower consensus on the magnitude of changes in climate variables, but several studies show that climate change has an impact on the availability and demand for water resources. Major rivers worldwide have experienced dramatic changes in flow, reducing their natural ability to adjust to and absorb disturbances. Given expected changes in global climate and water needs, this may create serious problems, including loss of native biodiversity and risks to ecosystems and humans from increased flooding or water shortages. This document analyzes the potential impact of climate change on water resources in Romania, Mehedinți County. The work ends with quantitative assessments of the effects of climate change on hydrology for a part of the Mehedinți County basins.

Abstract: The central dry zone area of Myanmar is characterized as vulnerable area due to water stressed and one of the most food insecure regions in the country. In this region, the adverse effects of climate change are believed to be a major constraint to vulnerability. Theses extreme climatic events are likely increase in frequency and magnitude of serious drought periods and extreme floods. For vulnerability assessment we used remote sensing (RS) and geographical information system (GIS) technology and develop a numerical model, using spatial principle component analysis (SPCA) in ArcGIS software and evaluate two decade (1995, 2005 & 2016) vulnerability evaluation. The model contains following indicators: discharge change, climate moisture, drained area, flood risk, irrigation, evapotranspiration, precipitation, surface runoff, nitrogen load and population distribution. According to the numerical results, the vulnerability is classified into five levels: slight, light, medial, heavy and very heavy level by means of the cluster principle. The results show that vulnerability in the study area from 1995 to 2016 is at medial (25%) and heavy (25%) level and presents from south-west to north east direction. The vulnerability change trend show worst situation in 1995 (29.80) and best one in 2005 (17.45) but again vulnerability was increase in 2016 (21.58). In the study area the main driving forces for dynamic change in vulnerability is the intensive land use and high population density. This spatial approach allowed the analysis of different indicators, providing a platform for data integration as well as a visually powerful overview of the study area.

Abstract: Timisoara is a growing city in the western part of Romania, in a seismic area, with a lot of masonry buildings with historical and cultural value, with interesting structural elements such as vaults, arches, slabs, walls, that were affected by earthquakes, subsidence of foundations, negative human actions or lack of interventions. Masonry historical structures in Banat seismic area present particular failure mechanisms, so there is a need for new, modern, fast, easy-to-apply and reversible consolidation methods. With this type of methods is possible to assure the local and global resistance, ductility, stability and rigidity for historical buildings. This article shows the consolidation methods that were applied on the buildings Sf. Gheorghe 3 and 4, in the historical centre of Timisoara, on masonry structures with historical value. The solutions that were applied are using new, innovative fibre-reinforced composite materials, in order to repair the existing damages and prevent further ones. The consolidation solutions with these new composite materials reduce the buildings vulnerability and present the advantage of being fast and easy to be executed.

Abstract: Romania is a country divided in two important seismic areas, with a history that has as proof buildings with historical and cultural value, most of them made in masonry. A large number of those buildings have suffered damages because of earthquakes, subsidence of foundations or lack of interventions. In this article will be presented some consolidation methods applied on masonry buildings in Romania, with composite fiber-reinforced materials, made by Kerakoll producer. Those modern consolidation solutions that were used in Romania may represent examples that can represent the base of choosing the consolidation methods for other buildings with similar damages.

Abstract: Despite being natural processes of the Earth’s surface dynamics, mass movements can be accelerated or sparked by human interference. Human activities such as developments in highly susceptible mass movements areas have been the main cause of accidents linked to landslides in Brazilian urban hillsides. In Natal - RN, the existence of areas with high declivity combined with inappropriate human occupation has been making the city vulnerable to stability problems of slopes. In this context, this work aimed to map the risk and analyze situations of hazard, vulnerability, and risk of incidence of mass movements present in São José do Jacó community, in Rocas neighborhood, Natal/RN. In order to map the risk, the methodology proposed by [1] was applied and adjusted to the characteristics of the study area. The mapping results showed that São José do Jacó presented a high degree of risk, ranging from high to very high. The analysis of hazard, vulnerability and risk has made possible to observe the factors that triggers mass movements in the area, among which: steep slopes, disordered cut slopes, dense occupation, inefficient drainage system, septic tanks and cesspools on the edge or in the middle of the talus and low/medium vegetation cover can be identified. The detailed research of the hazard, vulnerability and risk situations found in São José do Jacó community has enabled a better understanding of the area’s aspects, which lead to the obtention of high degree of risk.

Abstract: Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a reservoir system prior to analysis is advantageous because then the input data interval can be selected to match the requirement. In this sense, over-year systems (CP > 1 year) can be adequately analyzed using annual time-series data, whereas for within-year systems (CP < 1 year), only the critical 12 months in the data record are needed to be considered. The current standard demand parameter method for prediction of the behavior of reservoirs is based only on demand and coefficient of variation of annual flows. However, performance measures such as reliability and vulnerability are also important in the critical period of reservoir systems. Hence, the objective of this study, is to develop a predictive relationship for critical period involving standard demand parameter and both reliability and vulnerability performance indices as for use during the reservoir planning stage. The Johor catchment was selected as the case study. The reservoir was analyzed using a Monte Carlo simulation technique by modified SPA. The critical period prediction model was then calibrated based on the simulation results. Subsequently, the performance of the model was observed by comparing the model’s results with simulation outcomes for study systems. It was found that the performance of the model was very good in reproducing the critical period. In conclusion, it is promising given that this is the first equation to model critical period involving performance measures in Johor catchment as best of the authors’ knowledge.

Abstract: Storage–yield–reliability (S–Y–R) relationship is useful in many areas of hydrology and water resources. With the availability of such a relationship, reservoir planning analysis can be implemented much more rapidly and at a much shorter time needed for sequential analysis applying time series data. Existing relationships have been developed mostly for over-year capacity without considering both reliability and vulnerability performance indices. Hence, in this study, streamflow data from Johor river was used to develop a predictive relationship for total (i.e. within-year plus over-year) storage capacity involving both reliability and vulnerability performance indices as for use during reservoir planning. The reservoir was analyzed using 1000 sequences of synthetic data having the same length as historical data involving both time-based reliability and vulnerability performance indices by modified SPA. The model was then calibrated based on the mean of 1000 simulation results. Subsequently, the performance of the model was observed by comparing the model’s results with simulation outcomes for study systems. It was found that the performance of the model was very good in reproducing, the total storage capacity.