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Assessment of Climate Change-Induced Vulnerability to Floods in Hyderabad, India, Using Remote Sensing Data
Abstract
The frequency and intensity of extreme rainfall events over Hyderabad, India, are often the cause of devastating floods in
its urban and peri-urban areas. This paper introduces a quantitative approach to assessing urban vulnerability to floods in
Hyderabad, identifying informal settlements via high resolution satellite photography and through the development of a flood
model for urban and peri-urban areas.
... The connection between building environment and health is well known [9]. For example, slum dwellers are more vulnerable to different weather phenomena [10,11] or natural disasters, such as floods [12]. Egondi et al. [13] show that inadequate heating systems during cold periods lead to an increased mortality rate among slum dwellers. ...
... This type of study is also necessary for other regions of the world with regard to different classes of diseases [8]. In particular, because slum dwellers are exposed to increased risks, also with regard to climatic changes Chersich et al. [80] like more frequent heat waves [15], scarcity of water [112], the threat of flooding [12], it is important to investigate the connections between the physical building structure and health in more detail and to elaborate regional differences. ...
Approximately 1 billion slum dwellers worldwide are exposed to increased health risks due to their spatial environment. Recent studies have therefore called for the spatial environment to be introduced as a separate dimension in medical studies. Hence, this study investigates how and on which spatial scale relationships between the settlement morphology and the health status of the inhabitants can be identified. To this end, we summarize the current literature on the identification of slums from a geographical perspective and review the current literature on slums and health of the last five years (376 studies) focusing on the considered scales in the studies. We show that the majority of medical studies are restricted to certain geographical regions. It is desirable that the number of studies be adapted to the number of the respective population. On the basis of these studies, we develop a framework to investigate the relationship between space and health. Finally, we apply our methodology to investigate the relationship between the prevalence of slums and different health metrics using data of the global burden of diseases for different prefectures in Brazil on a subnational level.
... In India, previous studies have either focused on resilience in general at the city level (Jain und Bashir Bazaz 2016;Joerin et al. 2014;Waghwala und Agnihotri 2019) or informal settlements (Aboulnaga et al. 2021;Rumbach und Shirgaokar 2017;Thakore et al. 2022). Comparative studies have been done focusing on heat stress (Mahadevia et al. 2020), exposure and vulnerability to flooding (Kit et al. 2011;Mahadevia et al. 2019), and linking migration with resilience (Link et al. 2021). However, a comprehensive assessment of flood resilience with multiple indicators representing various societal aspects of formal and informal settlement has rarely been conducted. ...
Urbanization has resulted in increasing the pace of informality, specifically in developing countries like India. Informality is taking place at locations that are exposed to various hazards, and therefore, resilience building of both informal and formal settlements is needed to achieve sustainable development. Resilience assessment is key in defining appropriate area-specific resilience measures. Given that, this research assesses the resilience of formal and informal settlements of Surat city in India and presents implications for sustainable development. To assess resilience, an indicator-based approach was taken, using a household survey to collect the data. Analysis suggests that the resilience of formal and informal settlements is significantly different. Key differences were found in physical and institutional resilience, where informal settlements were found to be significantly less resilient than formal settlements. Several measures, such as gender-sensitive education and livelihood programs, as well as mobile water and sanitation, have positive implications for sustainable development. Overall, the study can guide disaster managers and policy makers to adopt a strategic and more targeted approach to strengthen resilience and achieve sustainable development.
... The articles by Blaikie and colleagues (2004) and Cutter and colleagues (2003) were outstanding in this regard: they found that rainfall, fluvial or coastal flooding in towns intersects with informal settlements, urban poverty, marginalisation and population density in areas exposed to these hazards (Dodman 2019; Douglas et al. 2008;Magadza 2000). Kit et al. (2011) confirmed that slums in Hyderabad, India, are often located in areas of rainwater accumulation. Ajibade and McBean's (2014) work in slum communities in Lagos, Nigeria, also highlighted how aspects such as limited access to housing or weak land rights push populations to settle on land potentially at greater risk of flooding. ...
The literature on vulnerability to flooding highlights the multiple dimensions of risk factors. However, little research has analysed the joint effects of environmental and social variables on flood risk at the household level in African cities. We use an interdisciplinary approach to analyse the differentiated significance of these dimensions for the status of 'flood victim' in Abidjan, the major city of Côte d'Ivoire. The data used were collected in a survey of 503 households residing in two contrasting neighbourhoods of Abidjan. Modelling data with logistic regressions, the results show that physical variables (the slope of the housing plot), environmental variables (liquid and solid waste disposal) and social variables (the gender of the head of household or the composition of the household) are factors jointly associated with flood risk. The multidimensional nature of vulnerability
... Researchers and urban planning authorities are confronting a great challenge to revamp the situation in urban settings because of the increased flooding trend in recent years (Bisht et al., 2016). Using remote sensing Kit et al. (2011) demonstrated that the storm peak occurs when the stormwater flow and informal settlements overlap along the flow path of stormwater in Hyderabad. Table 1 depicts the recent record of urban flood events in India and it was noticed that Hyderabad is facing frequent flood events. ...
Due to the dual pressure of rapid urbanization and climate change, urban flooding has become more common. Thus, for effective planning and mitigation strategies, it is of paramount interest to quantify the generated runoff and prioritize the urban critical sub-catchments. The present study investigates flood inundation in Hyderabad urban setting (zone-XII, zone-IV&V) using the Personal Computer Storm Water Management Model (PCSWMM) and prioritizes the critical sub-catchments using the compromise programming method (CPM) and PCSWMM. In addition, the system resilience is examined by integrating PCSWMM with GIS. The model simulation is performed for a 264 h (11 days) rainfall event that occurred in October 2020. The outcomes from the simulation are found to be satisfactory and in agreement with the field water logging points (WLPs). The inundation map results are validated with social media markers (SMMs). The critical sub-catchments are prioritized based on PCSWMM by runoff results and CPM by considering WLPs, slope and impervious percentage of sub-catchments as input criteria. The Integrated 1D-2D PCSWMM is used to examine the inundation velocity and depth. An urban flood hazard (UFH) map is generated to identify optimal low impact developments (LIDs). Subsequently, the present study showed how storage can improve the catchment capability and resilience of urban settings to tackle the excess stormwater.
HIGHLIGHTS
The flood inundation in an urban area is simulated using coupled 1D-2D PCSWMM.;
Inundation, risk and hazard map are generated.;
The prioritization of critical sub-catchments is carried out using multi-criteria decision-making methods.;
Assessment of resilience of the urban area is carried out using GIS and PCSWMM.;
... Marginalization of the poor has been observed inter alia in numerous coastal cities in India [54] and in Iliolo City in the Philippines [55]. Under inadequate urban management and unchecked growth, informal settlements commonly encroach more risk-prone areas where flood and cyclone exposure is high [56][57][58]. These areas are avoided by wealthier populations [11]. ...
Coastal areas are urbanizing at unprecedented rates, particularly in low- and middle-income countries. Combinations of long-standing and emerging problems in these urban areas generate vulnerability for human well-being and ecosystems alike. This baseline study provides a spatially explicit global systematization of these problems into typical urban vulnerability profiles for the year 2000 using largely sub-national data. Using 11 indicator datasets for urban expansion, urban population growth, marginalization of poor populations, government effectiveness, exposures and damages to climate-related extreme events, low-lying settlement, and wetlands prevalence, a cluster analysis reveals a global typology of seven clearly distinguishable clusters, or urban profiles of vulnerability. Each profile is characterized by a specific data-value combination of indicators representing mechanisms that generate vulnerability. Using 21 studies for testing the plausibility, we identify seven key profile-based vulnerabilities for urban populations, which are relevant in the context of global urbanization, expansion, and climate change. We show which urban coasts are similar in this regard. Sensitivity and exposure to extreme climate-related events, and government effectiveness, are the most important factors for the huge asymmetries of vulnerability between profiles. Against the background of underlying global trends we propose entry points for profile-based vulnerability reduction. The study provides a baseline for further pattern analysis in the rapidly urbanizing coastal fringe as data availability increases. We propose to explore socio-ecologically similar coastal urban areas as a basis for sharing experience and vulnerability-reducing measures among them.
... Marginalization of the poor has been observed inter alia in numerous coastal cities in India (Revi 2008) and in Iliolo City in the Philippines (Rayos Co 2010). Under inadequate urban management and unchecked growth, informal settlements commonly encroach more risk-prone areas where flood and cyclone exposure is high (Cardona et al. 2012;Kit et al. 2011;Satterthwaite 2007). These areas are avoided by wealthier populations (Prasad et al. 2009). ...
On a planetary scale human populations need to adapt to both socio-economic and environmental problems amidst rapid global change. This holds true for coupled human-environment (socio-ecological) systems in rural and urban settings alike. Two examples are drylands and urban coasts. Such socio-ecological systems have a global distribution. Therefore, advancing the knowledge base for identifying socio-ecological adaptation needs with local vulnerability assessments alone is infeasible: The systems cover vast areas, while funding, time, and human resources for local assessments are limited. They are lacking in low an middle-income countries (LICs and MICs) in particular. But places in a specific socio-ecological system are not only unique and complex – they also exhibit similarities. A global patchwork of local rural drylands vulnerability assessments of human populations to socio-ecological and environmental problems has already been reduced to a limited number of problem structures, which typically cause vulnerability. However, the question arises whether this is also possible in urban socio-ecological systems. The question also arises whether these typologies provide added value in research beyond global change. Finally, the methodology employed for drylands needs refining and standardizing to increase its uptake in the scientific community. In this dissertation, I set out to fill these three gaps in research. The geographical focus in my dissertation is on LICs and MICs, which generally have lower capacities to adapt, and greater adaptation needs, regarding rapid global change. Using a spatially explicit indicator-based methodology, I combine geospatial and clustering methods to identify typical configurations of key factors in case studies causing vulnerability to human populations in two specific socio-ecological systems. Then I use statistical and analytical methods to interpret and appraise both the typical configurations and the global typologies they constitute. First, I improve the indicator-based methodology and then reanalyze typical global problem structures of socio-ecological drylands vulnerability with seven indicator datasets. The reanalysis confirms the key tenets and produces a more realistic and nuanced typology of eight spatially explicit problem structures, or vulnerability profiles: Two new profiles with typically high natural resource endowment emerge, in which overpopulation has led to medium or high soil erosion. Second, I determine whether the new drylands typology and its socio-ecological vulnerability concept advance a thematically linked scientific debate in human security studies: what drives violent conflict in drylands? The typology is a much better predictor for conflict distribution and incidence in drylands than regression models typically used in peace research. Third, I analyze global problem structures typically causing vulnerability in an urban socio-ecological system - the rapidly urbanizing coastal fringe (RUCF) – with eleven indicator datasets. The RUCF also shows a robust typology, and its seven profiles show huge asymmetries in vulnerability and adaptive capacity. The fastest population increase, lowest income, most ineffective governments, most prevalent poverty, and lowest adaptive capacity are all typically stacked in two profiles in LICs. This shows that beyond local case studies tropical cyclones and/or coastal flooding are neither stalling rapid population growth, nor urban expansion, in the RUCF. I propose entry points for scaling up successful vulnerability reduction strategies in coastal cities within the same vulnerability profile. This dissertation shows that patchworks of local vulnerability assessments can be generalized to structure global socio-ecological vulnerabilities in both rural and urban socio-ecological systems according to typical problems. In terms of climate-related extreme events in the RUCF, conflicting problem structures and means to deal with them are threatening to widen the development gap between LICs and high-income countries unless successful vulnerability reduction measures are comprehensively scaled up. The explanatory power for human security in drylands warrants further applications of the methodology beyond global environmental change research in the future. Thus, analyzing spatially explicit global typologies of socio-ecological vulnerability is a useful complement to local assessments: The typologies provide entry points for where to consider which generic measures to reduce typical problem structures – including the countless places without local assessments. This can save limited time and financial resources for adaptation under rapid global change.
... A análise de textura de imagens de satélite de favelas e não-favelas de cidades de vários continentes demostrou, por meio de medidas de lacunaridade, uma correlação consistente entre os padrões sociais e espaciais, refletindo a dimensão e o aspeto material dos constituintes da forma urbanaedificação, rua, bloco, praçabem como elementos naturaisrio, mar, vegetação, etc. (Barros Filho e Sobreira, 2005;Kit et al., 2011;Owen, 2012). A relevância e a consistência desses achados levantam a questão se tais propriedades estariam subjacentes a mapas temáticos que descrevem propriedades urbanas diversas, notadamente aquelas relacionadas às propriedades configuracionais que descrevem assimetrias estruturais. ...
O artigo apresenta os resultados de uma investigação que visa integrar diferentes abordagens à análise da forma urbana. A metodologia proposta integra duas linhas de investigação: a) análise de textura de imagens de satélite de alta resolução com o uso de medidas fractais e de lacunaridade para descrever a distribuição espacial de pixéis com níveis de cinza semelhantes; b) Análise Gráfica Visual, do inglês Visual Graph Analysis (VGA), que descreve propriedades visuais de sistemas espaciais. Uma análise de segunda ordem é proposta para descrever a textura dos mapas VGA e investigar em que medida os padrões subjacentes de configuração e textura estão correlacionados. Os resultados apresentados demonstram a robustez dos procedimentos para identificar padrões sócio-espaciais distintos.
... A análise de textura de imagens de satélite de favelas e não-favelas de cidades de vários continentes demostrou, por meio de medidas de lacunaridade, uma correlação consistente entre os padrões sociais e espaciais, refletindo a dimensão e o aspeto material dos constituintes da forma urbanaedificação, rua, bloco, praçabem como elementos naturaisrio, mar, vegetação, etc. (Barros Filho e Sobreira, 2005;Kit et al., 2011;Owen, 2012). A relevância e a consistência desses achados levantam a questão se tais propriedades estariam subjacentes a mapas temáticos que descrevem propriedades urbanas diversas, notadamente aquelas relacionadas às propriedades configuracionais que descrevem assimetrias estruturais. ...
The article presents the results of an investigation that aims at integrating different approaches to the analysis of the urban form. The article is, therefore, mostly concerned with methodological procedures. The proposed methodology integrates two lines of investigation: a) texture analysis of high resolution satellite images using fractal and lacunarity measures to describe the spatial distribution of pixels with similar gray levels; b) Visual Graph Analysis (VGA) that describes visual and access properties of urban open spaces. A second order analysis is proposed in order to describe the texture of VGA maps and investigate to what extent the underlying configurational and texture patterns are correlated. The results reveal how robust the procedures are, particularly in identifying distinct socio-spatial patterns.
... The city's 66% lakes are sewage laden and 14% are encroached by slums; 72% of the city's lake reserve have lost catchment area (Gupta and Nair, 2011;Ranganathan, 2015). (Kit et al., 2011) used RS to show that vulnerability to floods in Hyderabad is highest when flow concentration and location of informal settlements overlap. ...
... For example, slum mapping can be performed using remote sensing imagery [43], but the classification often involves manual interpretation. This can be performed for individual cities [44,45] but is unlikely to be practicable over larger areas. Housing types in rural area may also be predictive of socioeconomic status; indeed, one of the DHS variables that goes into a composite household wealth indicator is roofing material, which can be easily observable in high resolution remote sensing imagery. ...
Vulnerability mapping reveals areas that are likely to be at greater risk of climate-related disasters in the future. Through integration of climate, biophysical, and socioeconomic data in an overall vulnerability framework, so-called "hotspots" of vulnerability can be identified. These maps can be used as an aid to targeting adaptation and disaster risk management interventions. This paper reviews vulnerability mapping efforts in West Africa conducted under the USAID-funded African and Latin American Resilience to Climate Change (ARCC) project. The focus is on the integration of remotely sensed and socioeconomic data. Data inputs included a range of sensor data (e.g., MODIS NDVI, Landsat, SRTM elevation, DMSP-OLS night-time lights) as well as high-resolution poverty, conflict, and infrastructure data. Two basic methods were used, one in which each layer was transformed into standardized indicators in an additive approach, and another in which remote sensing data were used to contextualize the results of composite indicators. We assess the benefits and challenges of data integration, and the lessons learned from these mapping exercises.
... If combined with extreme precipitation-induced flood risk map of the city (Kit et al., 2011), this study can identify newly established slums which settle on the most endangered sites. Since many of them consist of temporary housing units and lack the solidity of the infrastructure of long established slums, such settlements can be classified as particularly vulnerable ones. ...
Slums bilden einen wesentlichen Bestandteil vieler Stadtregionen des globalen Südens, wobei Indien die höchste Zahl an Slumbewohnern beherbergt. Die internationalen Unterschiede in der Definition des Begriffs "Slum" sowie Mängel bei der Datenerfassung haben eine hohe Fehlerwahrscheinlichkeit bei der Aufnahme von Slumbevölkerungszahlen und -standorten in globalem, nationalem und städtischem Massstab zur Folge. Das Hauptziel dieser Dissertation besteht darin, eine Vorgehensweise zur automatischen Erkennung von Slums mit Hilfe von hochauflösenden Satellitenbildern zu entwickeln, und diese Methode in der indischen Metropole Hyderabad anzuwenden. Diese Arbeit entwickelt ein mehrstufiges Satellitenbildbearbeitungsverfahren, welches in der Lage ist, eine schnelle Slumerkennung in Hyderabad durchzuführen. Das Verfahren beruht auf dem Verhältnis zwischen einem bestimmten Bereich räumlicher Heterogenität, ausgedrückt durch Lakunarität, und der Wahrscheinlichkeit, dass die Struktur eines Gebietes der Oberflächenstruktur eines Slums entspricht. Die Anwendung der hier vorgeschlagenen Methode produzierte zum ersten Mal einen plausiblen, räumlich kohärenten und politisch unverzerrten Datensatz über Slumstandorte und Slumbevölkerung für das gesamte Stadtgebiet von Hyderabad. Die Ergebnisse verdeutlichen die Unstimmigkeiten bei der bisherigen Erfassung der Slumbevölkerungszahlen sowie bei der offiziellen Anerkennung von Slums. Die multitemporale Satellitenbildauswertung zeigt ein Wachstum der Slumbevölkerungszahlen im Grossraum Hyderabad an und bietet Einblick in den zeitlich-räumlichen Slumwachstumprozess zwischen den Jahren 2003 und 2010. Diese Dissertation stellt einen wissenschaftlichen Beitrag zu den Themen Fernerkundung der Siedlungen und fortgeschrittene Bildbearbeitungsmethoden dar und bietet den unterschiedlichsten Parteien, für welche Slumdaten von Bedeutung sind, ein wichtiges Instrument.
... Half of the considered global climate models (AOGCMs from the IPCC AR4 model ensemble) project values within this range after they were statistically downscaled to the Hyderabad region . To identify which additional areas will be affected by severe flooding in the future a flow-accumulation analysis was performed (DEM taken from SRTM remote sensing, see Kit et al., 2011). To identify the exposure unit, a remote sensing (QuickBird satellite) based identification of slum areas was developed. ...
Bridging the global‐regional divide inclimate impact research for urban areas means to establish a comprehensive picture which covers all urban agglomeration of the world. This is different from the case of, e.g., hydrological impact modeling where coarse‐scaled (spatial and functional) global models and detailed regional studies have to be brought together. Therefore we suggest a structured approach towards a full spatial and functional coverage of urban impact analyses: (1) Filtering ‐ all urban agglomerations are identified where a specific Climate Change impact path is probably relevant or even the dominant one and (2) a targeted, fast quantitative impact assessment of the respective impact path is performed for these urban areas. Step (1) starts with the existing knowledge on potential urban impact paths and extracts through different natural, social and economic filtering steps the urban agglomerations where these impact paths have to be studied quantitatively. In step (2) this is done by applying a set of tools which are mainly based on urban remote sensing to overcome the data scarcity bottleneck. It occurs that single filtering steps and tools can be reused for different impact paths. To illustrate the approach we presenta filtering example, resulting in a global map which shows the urban agglomerations where the following impact path is relevant: pluvial flooding of slum settlements under increasing frequency of heavy rain events To exemplify step (2) we present a remote sensing based toolset for quantitative assessment.
O intenso processo de urbanização, principalmente em países em desenvolvimento, como o Brasil, tem provocado a expansão e o adensamento da ocupação do solo, inclusive em áreas ambientalmente frágeis, gerando impermeabilização crescente das áreas urbanas. De acordo com Righetto et al. (2017), esta impermeabilização é resultante da combinação entre o uso desordenado e a incapacidade de suporte do meio, sucedendo nos eventos de inundação. Segundo Rosa e Victorio (2018), as primeiras etapas da ocupação urbana, em território nacional, demonstram a sucessão do desenvolvimento embasado em condições desiguais, no acesso ao espaço e a moradias adequadas; que é representado, atualmente, por meio da existência de assentamentos precários. Nos assentamentos precários, em detrimento do desenvolvimento síncrono das melhorias de infraestrutura com o crescimento destes, existem falhas na efetividade do planejamento, assim a rede de drenagem não é capaz de acompanhar a sua expansão informal. O que por sua vez, sucede na incapacidade desta rede em atender à demanda da sua população e inviabiliza a garantia de preservação ambiental, tornando-os mais vulneráveis às inundações. Tais fenômenos vêm sendo amplamente discutidos e reconhecidos como uma das questões científicas prioritárias nas discussões ambientais (Bai et al., 2019). As inundações se constituem como ameaças aos assentamentos precários, causando impactos ao ambiente e à saúde pública, para tanto devem ser tratadas com uma gestão eficiente, sobretudo em áreas com maior vulnerabilidade mediante as dificuldades e ineficiência das políticas públicas em atender a esse contingente populacional. Assim, surge a necessidade de compreender como a forma de ocupação do espaço interfere na intercorrência de inundação, e de incorporar os estudos da morfologia urbana no planejamento dos sistemas de drenagem, para que as águas urbanas superficiais sejam escoadas em tempo hábil (Cui et al., 2019). Na literatura são encontrados alguns estudos que investigaram o modo como os fenômenos urbanos são influenciados pela morfologia, como no desenvolvimento urbano sustentável (Barau et al., 2015; Dadashpoor et al., 2019). Estes verificam que os padrões espaciais, os tipos de cobertura, as formas de ruas, a distribuição dos espaços livres, interferem na garantia e previsões de cenários que assegurem um desenvolvimento pautado na natureza.
Research on disaster response frequently uses volunteered geographic information (VGI), due to its capability to provide near real-time information during and after a disaster. It is much less commonly used in spatial planning related to disaster management. However, VGI appears to have considerable potential for use in spatial planning and offers some advantages over traditional methods. For example, VGI can capture residents' preferences in a much faster, more timely, and more comprehensive fashion than is possible with, for example, questionnaires and surveys. This research investigates the usefulness of VGI for planning flood evacuation shelters. Using Jakarta, Indonesia, as a case study, we use VGI to capture the locations of flood evacuation shelters based on residents' preferences during flood periods in 2013–2014 and 2014–2015 and compare these with the locations of official shelters. Floods frequently affect Jakarta and the city administration uses VGI in flood emergency responses. Moreover, Jakarta has been identified as having the largest number of active Twitter users among cities worldwide. Thus, Jakarta is an appropriate place to study the use of VGI for planning evacuation shelters. VGI generated by Twitter users was used to identify the shelter locations preferred by Jakarta residents, and more precisely the flood evacuees. Of 171,046 tweets using keywords relating to flood evacuation, the content of 306 tweets indicated that they had been sent from inside or near evacuation shelters. The spatial pattern showed that those tweets were sent from 215 locations, mostly located near flooded areas. The analysis further showed that 35.6% of these shelter locations preferred by residents intersected with the locations of official evacuation shelters. As a general conclusion, our study demonstrates the advantages of using VGI for spatial planning, which mainly relates to the ease of capturing community preferences over a large area.
The potential impacts of progressing climate change are alarming. Some adverse consequences are now unavoidable and adaptation measures are increasingly needful. This poses enormous challenges for emerging megacities in the Global South, which barely manage in current weather conditions. This paper introduces Fuzzy Cognitive Mapping as a new tool for structured, semi-quantitative assessments of climate change impacts and adaptation measures.
Fuzzy Cognitive Mapping is used to evaluate differences in sensitivities to heatwaves and rainstorms across socio-economic groups and for the ranking of useful adaptation options, based on 188 individual interviews to the impacts of extreme weather events in Hyderabad, India. The results of this multi-stakeholder assessment indicate that rainstorms affect low-income residents more than heatwaves, while the opposite is true for medium-income respondents. The latter are also less seriously affected by extreme weather in general. Profession, though, not income determines the kind of impact that people feel most affected by. Individual characteristics like age and gender do not significantly explain differences in the data, but religion does. This is because, in Hyderabad, Muslims live in the older, less serviced and more affected parts of the city. However, semi-quantitative scenario analyses suggest that, under future climate change, many parts of the city will become increasingly exposed to the effects of extreme weather. Planned investments in urban infrastructure will be seriously challenged by climate change and preventive adaptation measures are urgently needed to at least maintain the current level of quality of life. Investments in the health infrastructure appear to be most effective in reducing the impact of heatwaves and investments in the traffic infrastructure most effective in reducing the impact of rainstorms. However, looking at heat and rain events together—which is realistic as they are both projected to increase and often occur in the same year—reveals that investments in water infrastructure and management have greatest potential to reduce impacts across all localities and on all social groups, particularly the lower-income classes. This is because first-order impacts caused by inadequate water infrastructure often give rise to second- or third-order impacts. Addressing the root cause is the most effective way to break cause-and-effect chains and prevent proliferation of negative consequences. Similar studies are suggested in other cities in order to support adaptation mainstreaming in complex urban environments. Fuzzy Cognitive Mapping proved a useful, semi-quantitative tool for climate change impact and adaptation assessments.
This paper presents an approach to automated identification of slum area
change patterns in Hyderabad, India, using multi-year and multi-sensor
very high resolution satellite imagery. It relies upon a
lacunarity-based slum detection algorithm, combined with Canny- and
LSD-based imagery pre-processing routines. This method outputs plausible
and spatially explicit slum locations for the whole urban agglomeration
of Hyderabad in years 2003 and 2010. The results indicate a considerable
growth of area occupied by slums between these years and allow
identification of trends in slum development in this urban
agglomeration.
Lacunarity based measures can be described as texture recognition approaches that provide a flexible yet theoretically consistent mean of characterizing the morphology of urban spatial patterns across different scales. This paper proposes a comparison between the Gliding-Box and Differential Box-Counting algorithms based on the concept of lacunarity to recognize and classify textures of urban areas with different inhabitability conditions through the analysis of binary and grayscale images from 30 ® Quickbird sensor image samples from Recife (Brazil), captured in October 2001, with 250 x 250 meters in size. Results show that the Differential Box Counting algorithm applied in grayscale images improves the discrimination between textures from urban areas with different inhabitability conditions, and it reveals a strong correlation between urban morphology and socioeconomic patterns.
The Digital Elevation Model that has been derived from the February 2000 Shuttle Radar Topography Mission (SRTM) has been one of the most important publicly available new spatial data sets in recent years. However, the 'finished' grade version of the data (also referred to as Version 2) still contains data voids (some 836,000 km 2)—and other anomalies—that prevent immediate use in many applications. These voids can be filled using a range of interpolation algorithms in conjunction with other sources of elevation data, but there is little guidance on the most appropriate void-filling method. This paper describes: (i) a method to fill voids using a variety of interpolators, (ii) a method to determine the most appropriate void-filling algorithms using a classification of the voids based on their size and a typology of their surrounding terrain; and (iii) the classification of the most appropriate algorithm for each of the 3,339,913 voids in the SRTM data. Based on a sample of 1304 artificial but realistic voids across six terrain types and eight void size classes, we found that the choice of void-filling algorithm is dependent on both the size and terrain type of the void. Contrary to some previous findings, the best methods can be generalised as: kriging or inverse distance weighting interpolation for small and medium size voids in relatively flat low-lying areas; spline interpolation for small and medium-sized voids in high-altitude and dissected terrain; triangular irregular network or inverse distance weighting interpolation for large voids in very flat areas, and an advanced spline method (ANUDEM) for large voids in other terrains.
Extensive plot studies across Amazonia have demonstrated that there are large regional gradients in forest productivity and that the dynamics of the forests seem to have accelerated substantially in recent decades, with ensuing impacts on forest structure. Most of these sites are, however, one hectare plots nested within a heterogeneous landscape, and a clear need exists to understand the landscape and regional context of these studies. Remote sensing offers the potential to scale up from plot to higher landscape levels but it has proven complex to evaluate forest structure, and therefore biomass patterns in tropical areas, due to saturation, signal noises, and unclear relationships between reflectance values and structural properties, both for optical and radar systems. In this study, we explore the potential of a textural approach to detect landscape and regional variations in the structure of tropical forest canopies, as viewed from high resolution IKONOS satellite imagery. We used lacunarity analysis and a derived variable, the index of translational homogeneity (ITH), as a tool to search for structural and dynamic forest properties within and among different Amazonian landscapes. The main goals of this research were: (1) to examine the sensitivity and robustness of ITH analysis to details of the analysis procedure; (2) to explore the intra- and inter-regional textural properties of a variety of tropical forest canopies [Caxiuanã, Manaus, Sinop, Santarem (Brazil), and Tambopata (Peru)], and (3) to relate textural properties derived from lacunarity to structural properties of the forest canopy, mainly crown size. Our results show how ITH and lacunarity analyses offer insights into the spatial distribution of structural properties of forest canopies, easily differentiating between terra firme forests and swamp forests. The studied forest canopies are self-similar on length-scales of 5–11 m, and show translational invariance on scales above 20 m (central and western Amazonia) and 30 m (eastern Amazonia) For a restricted range of solar elevation angles, the ITH appears to be determined mainly by the mean size of tree crowns, and by the fraction of large (shadow-generating) trees.
Taking the Special Report on Emission Scenarios (SRES) climate and socio-economic scenarios (A1FI, A2, B1 and B2 'future worlds'), the potential impacts of sea-level rise through the twenty-first century are explored using complementary impact and economic analysis methods at the global scale. These methods have never been explored together previously. In all scenarios, the exposure and hence the impact potential due to increased flooding by sea-level rise increases significantly compared to the base year (1990). While mitigation reduces impacts, due to the lagged response of sea-level rise to atmospheric temperature rise, impacts cannot be avoided during the twenty-first century by this response alone. Cost-benefit analyses suggest that widespread protection will be an economically rational response to land loss due to sea-level rise in the four SRES futures that are considered. The most vulnerable future worlds to sea-level rise appear to be the A2 and B2 scenarios, which primarily reflects differences in the socio-economic situation (coastal population, Gross Domestic Product (GDP) and GDP/capita), rather than the magnitude of sea-level rise. Small islands and deltaic settings stand out as being more vulnerable as shown in many earlier analyses. Collectively, these results suggest that human societies will have more choice in how they respond to sea-level rise than is often assumed. However, this conclusion needs to be tempered by recognition that we still do not understand these choices and significant impacts remain possible. Future worlds which experience larger rises in sea-level than considered here (above 35 cm), more extreme events, a reactive rather than proactive approach to adaptation, and where GDP growth is slower or more unequal than in the SRES futures remain a concern. There is considerable scope for further research to better understand these diverse issues.
Hyderabad in India is a sprawling metropolis and an incipient megacity facing structural, environmental, social and economic problems. An interdisciplinary research approach provides a holistic perspective on the urban characteristics to develop strategies for a more sustainable future. Thus, a multi-scale analysis of the urban area by remote sensing provides up-to-date data of the urban morphology. An overview analysis with a time series of Landsat data shows the dynamic growth of the urban area, its direction as well as the current spatial extension. QickBird data enable a highly detailed analysis of the structural characteristics of specific neighborhoods. These data provide the spatial basis within the GIS database complemented by further information from the city administration (e.g. population data, land use data) and finally detailed data from surveys. The combination of various perspectives of temporal and spatial urban characteristics can be used by different disciplines. This enables a value-added and more holistic view to understand urban workflows and their dependencies.
This research highlights the potential of IKONOS satellite data to identify the temporary structures in a part of Dehradun, India. Houses with plastic roof covers reveal dark grey tone in merged IKONOS product, which helps to extract information about the people living below poverty line. Extent of these areas can be quantified using classification technique successfully. Mixing of shadow pixels with temporary structures poses limitation and need further research.
It is claimed that the abstract analytic continuation of hypercubic lattices to noninteger dimensionalities can be implemented explicitly by certain fractal lattices of low lacunarity. These lattices are special examples of Sierpinski carpets. Their being of low lacunarity means that they are arbitrarily close to being translationally invariant. The claim is substantiated for the Ising model in D=1+ε dimensions, and for resistor network models with 1
Correction for ‘Impacts and responses to sea-level rise: a global analysis of the SRES scenarios over the twenty-first century’ by Robert J. Nicholls and Richard S. J. Toll (Phil. Trans. R. Soc. A 364 , 1073–1095. (doi: 10.1098/rsta.2006.1754 )).
Figure 10 in the print version of this paper is incorrect; the correct figure is shown in the next page. The first full paragraph of p. 1089 in the print version of this paper is incorrect; the correct paragraph is as follows.
Software tools have been developed at the U.S. Geological Survey's EROS Data Center to extract topographic structure and to delineate watersheds and overland flow paths from digital elevation models. The tools are special purpose FORTRAN programs interfaced with general-purpose raster and vector spatial analysis and relational data base management packages. The first phase of analysis is a conditioning phase that generates three data sets: the original DEM with depressions filled, a data set indicating the flow direction for each cell, and a flow accumulation data set in which each cell receives a value equal to the total number of cells that drain to it. The original DEM and these three derivative data sets can then be processed in a variety of ways.
IPCC Special Report on Emissions Scenarios Contents: Foreword Preface Summary for policymakers Technical Summary Chapter 1: Background and Overview Chapter 2: An Overview of the Scenario Literature Chapter 3: Scenario Driving Forces Chapter 4: An Overview of Scenarios Chapter 5: Emission Scenarios Chapter 6: Summary Discussions and Recommendations
Special report on emissions scenarios: a special report of working group III of the intergovernmental panel on climate change Impacts and responses to sea-level rise: a global analysis of the SRES scenarios over the twenty-first century
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Nakićenović N, Swart R (eds) (2000) Special report on emissions scenarios: a special report of working group III of the intergovernmental panel on climate change. Cambridge University Press, Cambridge Nicholls RJ, Tol RSJ (2006) Impacts and responses to sea-level rise: a global analysis of the SRES scenarios over the twenty-first century. Philos Trans R Soc A 364(1841):1073–1095
Analysing Recife's Urban Fragments
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Amorim L, Barros Filho MN, Cruz D (2009) Analysing Recife's Urban Fragments. In: Koch
D, Marcus L, Steen J (eds) Proceedings of the 7th International Space Syntax Symposium,
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Hole-filled SRTM for the globe version 4, available from the CGIAR-CSI SRTM 90m Database
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Jarvis A, Reuter HI, Nelson A, Guevara E (2008) Hole-filled SRTM for the globe Version 4,
available from the CGIAR-CSI SRTM 90m Database. http://srtm.csi.cgiar.org. Cited 20
May 2010
Project report for: Hyderabad as a megacity of tomorrow: climate and energy in a complex transition towards sustainable Hyderabad - mitigation and adaptation strategies by changing institutions, governance structures, lifestyles and consumption patterns
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Lüdeke MKB, Budde M (2009) Evaluating climate change scenarios. From AOGCMs to Hyderabad.
Report for the Project: Hyderabad as a Megacity of Tomorrow: Climate and Energy in a Complex
Transition towards Sustainable Hyderabad -Mitigation and Adaptation Strategies by Changing
Institutions, Governance Structures, Lifestyles and Consumption Patterns, funded by Federal
Ministry of Education and Research (BMBF), Germany. Potsdam Institute for Climate Impact
Research, Postfach 601203, 14412 Potsdam
Registrar General and Census Commissioner
- India Census Of