scholarly journals Definition of Seismic Vulnerability Maps for Civil Protection Systems: The Case of Lampedusa Island

2016 ◽  
Vol 10 (1) ◽  
pp. 87-105 ◽  
Author(s):  
Panagiotis G. Asteris ◽  
Liborio Cavaleri ◽  
Fabio Di Trapani ◽  
Giuseppe Macaluso ◽  
Gaia Scaduto
Keyword(s):  
Urban Areas ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
City Centre ◽  
Civil Protection ◽  
Vulnerability Model ◽  
Historical Investigation ◽  
Vulnerability Maps ◽  
Definition Of ◽  
The City

The opportunity to locate and quantify the major criticalities associated to natural catastrophic events on a territory allows to plan adequate strategies and interventions by civil protection bodies involved in local and international emergencies. Seismic risk depends, most of all, on the vulnerability of buildings belonging to the urban areas. For this reason, the definition, by a deep analysis of the territory, of instruments identifying and locating vulnerability, largely favours the activities of institutions appointed to safeguard the safety of citizens. This paper proposes a procedure for the definition of vulnerability maps in terms of vulnerability indexes and critical peak ground accelerations for mid-small urban centres belonging to Mediterranean areas. The procedure, tested on the city centre of the Island of Lampedusa, is based on a preliminary historical investigation of the urban area and of the main formal and technological features of buildings involved. Moreover, the vulnerability of the constructions is evaluated by fast assessment methods (filling of evaluation forms). The vulnerability model, allowing the definition of the fragility curves, is calibrated on the basis of the results of an identification process of prototype buildings, selected to be adequately representative. Their characterizations have been provided using the results of an experimental dynamic investigation to develop high representative numerical model. Critical PGA values have been determined by pushover analyses.The results presented provided an unambiguous representation of the major criticalities with respect to seismic vulnerability and risk, of the city centre of the island, being a suitable tool for planning and handling of emergencies.

scholarly journals Improvement of the consideration of seismic risks in Algerian planning and urban development instruments: application to the Boumerdés region (50km east of Algiers/Algeria)

2020 ◽  
Vol 150 ◽  
pp. 03017
Author(s):  
Mohamed Yacine Kheliouen ◽  
Abdelmadjd Bouder
Keyword(s):  
Information System ◽  
Urban Areas ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Urban System ◽  
Empirical Method ◽  
Vulnerability Maps ◽  
Vulnerability Of Buildings ◽  
The City ◽  
Degree Of Isolation

The territory of both Algiers and Boumerdés departments was hit in 2003 by a violent earthquake of 6.8 (M) causing considerable human and material losses. In order to establish preventive solutions, the article recommend the seismic risk studies to be considered in national and urban planning instruments, It presents a seismic vulnerability study applied to three (03) cities located in the region that have high populations and challenges Two assessments are presented for each city: the first consists of studying the vulnerability of buildings to the earthquake using a qualitative empirical method called Risk-EU. The second assessment focuses on the unbuilt part of the city through the analysis of evacuation and rescue capacity after the earthquake. This latter is a method used in the seismic micro zoning study of the wilaya of Algiers that was jointly established by 02 Japanese and Algerian study centers. The superposition of the summary vulnerability maps of the two assessments designed using a geographic information system (GIS), shows us the location of the most vulnerable urban areas. Damage of the building is coupled with their degree of isolation that serves for evacuation and rescue in the case of an earthquake. The results of cumulative vulnerability (built and urban system) at the scale of the region studied, then at each city and districts, are shown graphically and statistically.

scholarly journals Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca
Keyword(s):  
Data Fusion ◽  
Spatial Variability ◽  
Urban Areas ◽  
Road Traffic ◽  
Dispersion Model ◽  
Low Cost ◽  
Spatial Modelling ◽  
City Centre ◽  
Small Scale ◽  
The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

scholarly journals Green Spaces in Residential Areas of Dar es Salaam City: Types, Coverage and Uses

2021 ◽  
Vol 14 (3) ◽  
pp. 121
Author(s):  
Nicholaus Mwageni ◽  
Robert Kiunsi
Keyword(s):  
Urban Areas ◽  
Green Space ◽  
Dar Es Salaam ◽  
Economic Benefits ◽  
Natural Vegetation ◽  
Green Spaces ◽  
City Centre ◽  
Building Density ◽  
Dar Es Salaam City ◽  
The City

Green spaces in urban areas including in Dar es Salaam City provide multiple ecological, social and economic benefits. Despite their benefits they are inadequately documented in terms types, coverage and uses. This paper attempts to provide information on types, coverage and uses of green space in Dar es Salaam City. A number of methods including literature review, interpretation of remotely sensed image, interviews, focus group discussions and questionnaires were used to document city greenery. The research findings show that residential greenery is made up of greenery found within and external to plots. The dominant green spaces external to residential plots were natural and semi natural vegetation while within plots were woody plants, plots farms vegetable and ornamental gardens. Distribution of greenery varied among the wards due to differences in building density and distance from the city centre. Natural and semi natural vegetation increased with decrease of building density and increase of distance from the city centre, while the number of plots with trees for shade increased with increase of building density. Only Kawe ward that had greenery above Tanzania space planning standards, the other three wards which are informal settlements had green space deficit. Three quarters of the households use green spaces for shade provision and cooling, two thirds as a source of food products and a quarter for recreation and aesthetic purposes. The study reveals that Dar es Salaam City residents invest predominantly on shade trees in their residential plots compared to other green space types.

Agriculture in urban and peri-urban areas in the United States: Highlights from the Census of Agriculture

2014 ◽  
Vol 30 (1) ◽  
pp. 64-78 ◽  
Author(s):  
Stephanie Rogus ◽  
Carolyn Dimitri
Keyword(s):  
Urban Areas ◽  
Census Data ◽  
Current Trend ◽  
The United States ◽  
Land Values ◽  
Local Policy ◽  
Urban Core ◽  
Definition Of ◽  
Vegetable Farm ◽  
The City

AbstractUrban agriculture, a current trend in many US cities, is purported to bring enhanced food security, reduction of food waste, community building, open green space in cities and higher property values. However, the literature lacks an understanding of whether urban farming has extended beyond a compelling concept into the practice of farming in the city and peri-urban areas. The exact definition of an urban farm is challenging, since many urban farms have a primary mission of supporting social goals rather than providing food. Use of the USDA definition of farm omits many self-identified urban farms, but the most consistent measure of agriculture is the Census of Agriculture. Using census data, this paper finds that urban farms are smaller than the typical farm, and while the amount of urban and peri-urban farmland declined between 2002 and 2007, the total number of farms increased. Growth in farmland is positively related to land values, suggesting that increases in urban farmland are more likely to take place in population dense, land scarce areas. Spatial analysis of urban and peri-urban farms in the Northeast finds fewer clusters of farms in areas with high land costs. In the most populous Northeastern cities, the farms are more likely to be located in the peri-urban area than in the urban core. Urban farms in the Northeast were more likely to produce vegetables, eggs and goats. Significant levels of vegetable farm clusters were detected surrounding Providence, Boston and Hartford Metropolitan Statistical Areas, which are regions that had no significant level of clustering of total farms. Future analysis, incorporating data from the 2012 census, should provide insight into whether local policy changes have resulted in growth in urban farms and farmland.

Seismic risk assessment of RC curved bridges through fragility curves

2019 ◽  
Author(s):  
Nina N. Serdar ◽  
Jelena R. Pejovic ◽  
Radenko Pejovic ◽  
Miloš Knežević
Keyword(s):  
Risk Assessment ◽  
Urban Areas ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Curved Bridges ◽  
Damage State ◽  
Seismic Risk Assessment ◽  
Probability Of Exceedance ◽  
Damage States

<p>It is of great importance that traffic network is still functioning in post- earthquake period, so that interventions in emergency situations are not delayed. Bridges are part of the traffic system that can be considered as critical for adequate post-earthquake response. Their seismic response often dominate the response and reliability of overall transportation system, so special attention should be given to risk assessment for these structures. In seismic vulnerability and risk assessment bridges are often classified as regular or irregular structures, dependant on their configuration. Curved bridges are considered as irregular and unexpected behaviour during seismic excitation is noticed in past earthquake events. Still there are an increasing number of these structures especially in densely populated urban areas since curved configuration is often suitable to accommodate complicated location conditions. In this paper special attention is given to seismic risk assessment of curved reinforce concrete bridges through fragility curves. Procedure for developing fragility curves is described as well as influence of radius curvature on their seismic vulnerability is investigated. Since vulnerability curves provide probability of exceedance of certain damage state, four damage states are considered: near collapse, significant damage, intermediate damage state, onset of damage and damage limitation. As much as possible these damage states are related to current European provisions. Radius of horizontal curvature is varied by changing subtended angle: 25 °, 45 ° and 90 °. Also one corresponding straight bridge is analysed. Nonlinear static procedure is used for developing of fragility curves. It was shown that probability of exceedance of certain damage states is increased as subtended angle is increased. Also it is determined that fragility of curved bridges can be related to fragility of straight counterparts what facilitates seismic evaluation of seismic vulnerability of curved bridges structures.</p>

Urban DAS recording of a vibroseismic campaign with a 21km-long dark fibre in Potsdam, Germany

2021 ◽  
Author(s):  
CharLotte Krawczyk ◽  
Christopher Wollin ◽  
Stefan Lüth ◽  
Martin Lipus ◽  
Christian Cunow ◽  
...  
Keyword(s):  
Urban Areas ◽  
District Heating ◽  
Telecommunication Networks ◽  
Seismic Exploration ◽  
City Centre ◽  
Data Set ◽  
Geothermal Potential ◽  
First Results ◽  
Local Geology ◽  
The City

&lt;p&gt;The de-carbonization strategy of the city of Potsdam, Germany, incorporates the utilization of its geothermal potential.&amp;#160; As a first step of developing a deep geothermal project for district heating, an urban seismic exploration campaign of the Stadtwerke Potsdam took place in December 2020 in the city centre of Potsdam.&amp;#160; Since urban measurements are often difficult to setup and a low-footprint alternative is sought for, we supplemented the contractor-performed Vibroseis survey along three profiles by distributed acoustic sensing (DAS).&amp;#160; In close cooperation with the municipal utilities, we interrogated a 21 km-long dark telecommunication fibre whose trajectory followed the seismic lines as close as possible.&amp;#160; This was accompanied by a network of 15 three-component geophones for further control and research.&lt;/p&gt;&lt;p&gt;In this contribution we present the data set, the approach for geo-referencing the fibre, and first results regarding DAS recording capabilities of vibroseismic signals in an urban environment.&amp;#160; Following the paradigm that the high density of telecommunication networks in urban areas may facilitate the exploration of the often insufficiently known local geology, we strive to further shed light on the possibilities of their employment for urban exploration.&amp;#160; In this respect we aim at tackling the question of the accuracy of fibre localization, recording sensitivity and range of active stimulation.&lt;/p&gt;

scholarly journals Multi-risk assessment in a historical city

2022 ◽  
Author(s):  
C. Arrighi ◽  
M. Tanganelli ◽  
M. T. Cristofaro ◽  
V. Cardinali ◽  
A. Marra ◽  
...  
Keyword(s):  
Probability Distribution ◽  
Urban Development ◽  
Natural Hazards ◽  
Seismic Vulnerability ◽  
Joint Probability ◽  
World Heritage Site ◽  
City Centre ◽  
Ex Post ◽  
Average Annual Loss ◽  
The City

AbstractNatural hazards pose a significant threat to historical cities which have an authentic and universal value for mankind. This study aims at codifying a multi-risk workflow for seismic and flood hazards, for site-scale applications in historical cities, which provides the Average Annual Loss for buildings within a coherent multi-exposure and multi-vulnerability framework. The proposed methodology includes a multi-risk correlation and joint probability analysis to identify the role of urban development in re-shaping risk components in historical contexts. The workflow is unified by exposure modelling which adopts the same assumptions and parameters. Seismic vulnerability is modelled through an empirical approach by assigning to each building a vulnerability value depending on the European Macroseismic Scale (EMS-98) and modifiers available in literature. Flood vulnerability is modelled by means of stage-damage curves developed for the study area and validated against ex-post damage claims. The method is applied to the city centre of Florence (Italy) listed as UNESCO World Heritage site since 1982. Direct multi-hazard, multi-vulnerability losses are modelled for four probabilistic scenarios. A multi-risk of 3.15 M€/year is estimated for the current situation. In case of adoption of local mitigation measures like floodproofing of basements and installation of steel tie rods, multi-risk reduces to 1.55 M€/yr. The analysis of multi-risk correlation and joint probability distribution shows that the historical evolution of the city centre, from the roman castrum followed by rebuilding in the Middle Ages, the late XIX century and the post WWII, has significantly affected multi-risk in the area. Three identified portions of the study area with a different multi-risk spatial probability distribution highlight that the urban development of the historical city influenced the flood hazard and the seismic vulnerability. The presented multi-risk workflow could be applied to other historical cities and further extended to other natural hazards.

Effectiveness of seismic strengthening to repeated earthquakes in historic urban contexts

2019 ◽  
Vol 29 (1) ◽  
pp. 47-64
Author(s):  
Valentina Putrino ◽  
Dina D’Ayala
Keyword(s):  
Seismic Vulnerability ◽  
Residential Buildings ◽  
Central Italy ◽  
Assessment Method ◽  
Qualitative Assessment ◽  
City Centre ◽  
General Context ◽  
Good Correspondence ◽  
Content Type ◽  
The City

Purpose The purpose of this paper is to discuss the dynamics of the evolution of damage to the residential buildings within the city walls of Norcia during the six-month seismic swarm that hit Central Italy in the period 24th August 2016 to end of January 2019. This is accomplished by comparing the damage recorded by the Italian Civil Protection usability form (AEDES form) during this period after each event. Design/methodology/approach First, these outputs are compared with a qualitative assessment conducted by means of omnidirectional camera (ODC) imagery collected on site by the authors, to explore the ability of this technology to support post-earthquake damage assessment. The damage level attributed with these two techniques is then further compared with the output of the analytical vulnerability assessment method FaMIVE, which allows to correlate damage to vulnerability. Specifically, the objective is to investigate the efficacy and performance of historic and recent strengthening interventions. Findings Results show that there is a good correspondence between AeDES and ODC assessments for low to medium damage grades (DG). Discrepancies in higher DGs are discussed in light of the different levels of information that can be recorded by using the two tools. The efficacy of strengthening is also well captured by the FaMIVE method. The procedure estimates a decrease of almost 40, 25 and 20 per cent of the total number of buildings failing out-of-plane, respectively, for the three seismic events considered, when restraining elements are in action. Research limitations/implications The analysis conducted in this work make use of deterministic values of Norcia’s masonry fabric characteristics that have been found in literature, thus implying that neither the probabilistic aspects nor the related uncertainties have been properly investigated and addressed. However, this limitation is to be considered within the more general context of the legislation for the preservation of historic buildings which limits substantially any type of semi-destructive tests, hence limiting the reliability of the values available in literature. This in turn affects the decisions informing the design and implementation of strengthening interventions which can be confidently considered reliable and effective. Originality/value The paper addresses for the first time a systematic investigation of damage progression in historic masonry structures, part of urban aggregates in heritage cities. The current urban fabric is discussed in view of historic building codes as the basis for determining the present seismic vulnerability of the historic city centre of Norcia. The study provides new data sets for the city of Norcia and develops a statistical correlation between cumulative damage and analytical vulnerability functions for heritage buildings exposed to a swarm of earthquakes. The analytical assessment of the effect of historic strengthening is totally novel.

Analysis of temperature trends and urban heat island in Madrid

2020 ◽  
Author(s):  
Gregorio Maqueda ◽  
Carlos Yagüe ◽  
Carlos Román-Cascón ◽  
Encarna Serrano ◽  
Jon Ander Arrillaga
Keyword(s):  
Urban Heat Island ◽  
Urban Areas ◽  
Surface Energy Budget ◽  
City Centre ◽  
Synoptic Situation ◽  
Heat Island ◽  
Temperature Trends ◽  
Measuring Period ◽  
Urban Heat ◽  
The City

&lt;p&gt;The temperature in the cities is affected by both global climate change and local changes due to human activities and the different land use compared to rural surroundings. These local changes, which modify the surface energy budget in urban areas, include the replacement of the natural surfaces by buildings and pavements and the heat of anthropogenic origin (heating, air conditioning, traffic). Madrid city (Spain) has a current population of near 3.3 million people and a larger metropolitan area reaching around 6.5 million people. Hence, it is affected by the phenomenon called urban heat island (UHI), which indicates that a higher temperature is found in the city compared with the surrounding rural areas. UHI is defined as the temperature difference between the urban observatory and the rural one and especially affects the minimum temperatures since urban areas cool down to a lesser extent than the neighbouring rural sites. Moreover, the intensity of the UHI is modulated by the meteorological conditions (wind, cloudiness, surface pressure, precipitation), highly associated with different synoptic situations. In this work, we use the Madrid-Retiro meteorological station as the urban one, which has regular and homogeneous data from the beginning of XX century; and the station at Barajas airport (12 km from the city centre) as well as other stations out of Madrid city (but within a range of 20 km from the city centre) as the rural stations. They all have a common measuring period from 1961 until present. The main objectives of the work are: 1) to identify temperature trends in the meteorological stations (both urban and rural); 2) to evaluate the intensity of the UHI for the different rural stations; 3) to apply a systematic and objective algorithm to classify each day in different categories (related to synoptic situation) that produce a different degree of UHI intensity; and, 4) to evaluate possible trends in the UHI intensity.&lt;/p&gt;

scholarly journals In the shadow of the urban regeneration megaproject: Urban transitions in downtown Łódź, Poland

2018 ◽  
Vol 56 (4) ◽  
pp. 41-52
Author(s):  
Jarosław Kazimierczak ◽  
Piotr Kosmowski
Keyword(s):  
Public Space ◽  
Urban Areas ◽  
Large Scale ◽  
Urban Regeneration ◽  
Point Of View ◽  
Business Community ◽  
City Centre ◽  
Functional Changes ◽  
Post Industrial ◽  
The City

Abstract The Nowe Centrum Łodzi project that was completed in 2007 in Łódź, Poland is one of the biggest contemporary large-scale urban (re)development projects in Europe and the largest project of this type in Central Europe. The principal goals of the mega-project in question include the regeneration of degraded post-industrial and post-railway land in the city centre of Łódź and the enhancement of competitiveness and the metropolitan position of the city. The authors seek to identify spatial and functional changes at a mezo-scale, i.e. in the so-called immediate neighbourhood of the urban regeneration megaproject (URMP), which have accompanied the implementation of the Nowe Centrum Łodzi project over the years 2013–2016. The other aim was to classify urban areas neighbouring the URMP based on features of spatial and functional transformation identified in these areas. The studies allowed the researchers to identify three categories of urban area in the immediate neighbourhood of the URMP which revealed differences in spatial and functional transformations. We indicated that the transformation of the immediate neighbourhood of the URMP involved not only the local authorities responsible for the overall improvement of the quality of public space but also other users, inter alia, residents, local urban activists, the business community, public institutions, and NGOs, that in most cases complemented efforts initiated by the Municipality. From the methodological point of view the authors use a case study including desk research, an urban planning inventory, and direct observation.

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