South Asian Cities Research Articles

Quantifying social segregation in large-scale networks

We present a measure of social segregation which combines mobile phone data and income register data in Oslo, Norway. In addition to measuring the extent of social segregation, our study shows that social segregation is strong, robust, and that social networks are particularly clustered among the richest. Using location data on the areas where people work, we also examine whether exposure to other social strata weakens measured segregation. Lastly, we extend our analysis to a large South Asian city and show that our main results hold across two widely different societies.

Cohort Profile: The Center for cArdiometabolic Risk Reduction in South Asia (CARRS).

... Emerging data, largely from the diaspora and largely cross-sectional, indicate that South Asians exhibit high rates of cardiovascular disease (CVD), diabetes, atypical dyslipidaemia profiles, and hepatic steatosis1–7 at lower body weight and younger ages relative to populations with European and other ancestries.8–10 It is hypothesized that these differences are rooted in some combination of distinctive pathophysiology, risk factor, phenotypic and socioeconomic characteristics.11–13 In addition, South Asia exhibits differences in health service use, health care costs and quality of care compared with high-income countries (HICs).14 Well-characterized prospective epidemiological cohorts help study the natural history of diseases and the evolution of care in the region. This can advance the knowledge and science of cardiometabolic diseases and provide the infrastructure for interdisciplinary and dynamic scientific explorations.15 The Center for cArdiometabolic Risk Reduction in South Asia (CARRS) is a population-based representative sociodemographically diverse cohort of 30 874 adults with prospective follow-up in three major cities in South Asia—Chennai and Delhi in India and Karachi in Pakistan.16

An improved understanding of NOx emissions in South Asian megacities using TROPOMI NO2 retrievals

Identifying air pollutant emissions has played a key role in improving air quality and hence the health of billions of people around the world. Central to this effort are the development of emission inventories and the mapping of air pollution using satellite remote sensing. The TROPOspheric Monitoring Instrument (TROPOMI) has been providing high resolution vertical column densities of nitrogen dioxide since late October 2018. Using the flux divergence method and a Gaussian Mixture Model, we identify peak emission hotspots over four cities in South Asia: Dhaka, Kolkata, Delhi and Lahore. We analyze data from November 2018 to March 2021 and focus on the three dry seasons (November to March) for which retrievals are available. The retrievals are shown to have sufficient spatial resolution to identify individual point and area sources. We further analyze the length scale and eccentricities of the hotspots to better characterize the emission sources. The TROPOMI emission estimates are compared with the EDGAR global emission inventory and the REAS regional inventory. This reveals areas of agreement but also significant discrepancies that should enable improvements and refinements of the inventories in the future. For example, urban emissions are underestimated while power generation emissions are overestimated. Some areas of light manufacturing cause significant signatures in TROPOMI retrievals but are mostly missing from the inventories. The spatial resolution of the TROPOMI instrument is now sufficient to provide detailed feedback to developers of emission inventories as well as to inform policy decisions at the urban to regional scale.

Floral Diversity Status in Urban Coastal Wetland & Associated Coastal Ecosystems of Crow Island Mattakkuliya, Sri Lanka

Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow Island wetland contributes diverse habitats for numerous flora and fauna species. The present study was conducted to assess the status of floral diversity in the Crow Island Beach Park and associated coastal ecosystem during the months of August to October 2021. Study area is divided in to three sites (A, B, C). Line transects method and field observations were used in the study. This coastal wetland consists of mosaic of five major vegetation types: Herbaceous, tree, shrub, creeper, grass and other than that marine algae namely Chaetomorpha antennina, Rhizoclonium africanum, Ulva compressa belonging to chlorophyta (green algae) and Grateloupia lithophila belonging to rhodophyta (red algae) were found in the study area. A total number of 102 flora species belonging to 50 families were recorded from the study area. There were two true mangrove species and 16 mangrove associated species in the study sites. Out of the 102 plant species 46 were recognized and documented as plants with medicinal values. Shannon-Wiener diversity indexes for mangrove and mangrove associated species were recorded as 2.378, 2.304 and 1.676 in site A, B and C respectively. Simpson’s diversity index for mangrove and mangrove associated species was recorded as 0.889, 0.874 and 0.735 respectively in site A, B and C and Jaccard index of similarity between three study sites showed high values ranging from 41% to 69% for mangrove and mangrove associated species.

Building Resilience to Compounding Urban Crises in South and Southeast Asian Cities in Times of Global Uncertainties

Building Resilience to Compounding Urban Crises in South and Southeast Asian Cities in Times of Global Uncertainties

Harnessing artificial intelligence and big data for SDGs and prosperous urban future in South Asia

Artificial intelligence (AI) and big data solutions are currently being utilized to offer low cost and efficient solutions in solving pressing urban socio-economic and environmental problems globally. The study found big data and AI have the potentiality to solve the common urban problems in South Asia and upsurge the efficiency of urban industries, increase competitiveness and productivity of the human and natural resources, reduce the cost of urban service delivery, and build climate resilience. The study has assessed the current AI and big data initiatives and technologies in mitigating the urban development challenges and their potentiality for scaling up in South Asian cities. The study also examined the latest innovations in AI and big data solutions for SDG monitoring and implementation in South Asia and their implication for transformational change. The study suggested that South Asia can harness the maximum benefit of AI and big data technologies by building big data and associated IT infrastructure, advancing research and innovations with regional cooperation, enhancing technological readiness, and eliminating week enabling conditions.

Diet Intake and Patterns in Adults With and Without Depression in South Asia

Abstract Objectives To compare dietary intake and patterns among adults with and without depression in South Asia. Methods Baseline survey data from the 2015–16 Centre for cArdiometabolic Risk Reduction in South-Asia study, representative of three urban South Asian cities (n = 13 588), were analyzed. Non-pregnant adults ≥ 20 years completed interviewer-administered surveys including a semi-quantitative Food Frequency Questionnaire (FFQ) and Patient Health Questionnaire-9 (PHQ-9) to assess depression. Participants were categorized as having moderate/severe depression (PHQ-9 = 10–27), mild depression (PHQ-9 = 5–9), and no depression (PHQ-9 = 0–4). FFQ data were transformed into daily food (g/d) and beverage (ml/d) intake. Among adults with and without depression, we compared differences in socio-demographic characteristics and daily food and nutrient intake (energy and macronutrients and their distributions) using Students t tests and chi-sq tests and determined diet patterns using exploratory factor analysis. Results Overall,16% (95% CI 14.7, 17.5) had mild depression and 6% (95% CI 5.1, 7.1) had moderate/severe depression. Compared with adults with no or mild depression, adults with moderate/severe depression had lower intake of energy (2196 ± 804 [no] vs. 2408 ± 852 [mild] vs. 2751 ± 902 [moderate/severe] kcal/d), carbohydrates (284 ± 102 vs. 318 ± 117 vs. 366 ± 125 g/d)), protein (77 ± 35 vs. 81 ± 36 vs. 87 ± 33g/d)), fat (81 ± 36 vs. 88 ± 37 vs. 101 ± 39 g/d), and all food groups except meat (41 ± 83 vs. 41 ± 97 vs. 28 ± 73 g/d) and poultry (132 ± 146 vs. 107 ± 143 vs. 76 ± 113 g/d). Across groups, diets comprised 51–53% carbohydrates, 12–14% protein, and 32–33% fat. Four distinct diet patterns were seen among adults without depression (traditional, modern, non-vegetarian, vegetarian), with mild depression (traditional, western, vegetarian, non-vegetarian), and with moderate/severe depression (traditional, energy-dense, western, non-vegetarian). Conclusions Diets of South Asian adults with depression were poorer in quality and quantity than those without depression. Efforts are needed to better study the direction of these associations and ways to improve diets of South Asians. Funding Sources NHLBHI, NIH, Oxford Health Alliance Vision 2020 of the UnitedHealth Group, Fogarty International Center and the Eunice Kennedy Shriver NIDDK, NIH and the Emory Global Health Institute.

The Relationship between Neighborhood Characteristics and Homicide in Karachi, Pakistan

The geographical concentration of criminal violence is closely associated with the social, demographic, and economic structural characteristics of neighborhoods. However, few studies have investigated homicide patterns and their relationships with neighborhoods in South Asian cities. In this study, the spatial and temporal patterns of homicide incidences in Karachi from 2009 to 2018 were analyzed using the local indicators of spatial association (LISA) method. Generalized linear modeling (GLM) and geographically weighted Poisson regression (GWPR) methods were implemented to examine the relationship between influential factors and the number of homicides during the 2009–2018 period. The results demonstrate that the homicide hotspot or clustered areas with high homicide counts expanded from 2009 to 2013 and decreased from 2013 to 2018. The number of homicides in the 2017–2018 period had a positive relationship with the percentage of the population speaking Balochi. The unplanned areas with low-density residential land use were associated with low homicide counts, and the areas patrolled by police forces had a significant negative relationship with the occurrence of homicide. The GWPR models effectively characterized the varying relationships between homicide and explanatory variables across the study area. The spatio-temporal analysis methods can be adapted to explore violent crime in other cities with a similar social context.

Engels’ ‘proletarisation’ and ‘great towns’ vis-à-vis dispossession, and gendered work in an informal economy

Through a powerful investigation of Engels’ The Condition of the Working Class in England (1845), this paper aims to study the conditions of the working-class population in an Indian metropolis in present times. The paper borrows from an empirical case study of working-class population in Narela, a peripheral region in Delhi, to assess the relationship among labour, capital and state. With deepening inequality, changing labour market relations and spatial restructuring in cities, it becomes essential to understand this relationship in light of existing scholarships on South Asian cities focussing on everyday state, urban informality, social reproduction and periphery. The spatial reorganisation of Delhi was premised on aesthetic improvisation of the city, which aimed at driving the polluting/hazardous industries and working-class population to the peripheral area of Narela in the late 1990s and early 2000s. Drawing from the lived experiences of the displaced workers and new migrant workers, this study addresses concerns around housing and employment, therefore looking at a larger relationship among labour, state and capital. Explaining the process of peopling and industrialisation of this peripheral region, the paper critically analyses the contributions as well as limitations of Engels’ work in Indian urban studies.

Geographies of outdoor play in Dhaka: an explorative study on children’s location preference, usage pattern, and accessibility range of play spaces

ABSTRACT This paper explores children’s (aged 7–16) outdoor play in terms of location preference, usage pattern, and accessibility range of play spaces in three neighbourhoods in Dhaka. Data were collected through a survey of children and their respective parents, interviews with children, and observation of play activities in 21 play spaces. Analytical results reveal diverse geographies of children’s outdoor play across gender, age, family income, urban areas, and length of stay. The preferences for outdoor play and intensity of use of the play spaces were significantly lower among girls compared to boys. The frequency of access to play spaces decreased exponentially with the distance between children’s home and play space (exponent of distance-decay = 0.346 per 100 m). Results add evidence to the everyday geographies of children’s outdoor play and inform urban planners in their efforts to create better play environments for and with children in high-density South Asian cities.

Spatial Analysis of Urbanization Patterns in Four Rapidly Growing South Asian Cities Using Sentinel-2 Data

The rapid and dominant urbanization in Asian cities has fueled concerns regarding the local and global efforts toward urban sustainability. Specifically, South Asian cities have been a topical issue concerning ecological and environmental threats due to their unplanned and haphazard urban development. However, comparative urbanization studies in South Asian cities remain uncommon. Therefore, in this study, we sought to comparatively examine the land use and land cover (LULC) dynamics and to detect the urbanization patterns of four rapidly developing South Asian lowland cities: Mumbai (India), Colombo (Sri Lanka), Karachi (Pakistan), and Dhaka (Bangladesh). Sentinel-2 (10 m) data and various geospatial approaches, including urban–rural gradient and grid-based methods, statistics, and urban landscape metric techniques, were used to facilitate the analysis. The study revealed that Mumbai, Karachi, and Dhaka had larger built-up landscapes compared to Colombo. Mumbai had the highest percentage of green spaces, followed by Colombo. Dhaka and Karachi had relatively small percentages of green spaces. Colombo and Dhaka had more croplands, which consistently increased along the urban–rural gradient compared to Mumbai and Karachi. Karachi showed that the only major land use was built-up, while most of the areas were left as open lands. On the other hand, Colombo’s urban setup was more fragmented than the other three cities. Mumbai and Karachi had larger patches of urban footprints compared to Colombo and Dhaka. Thus, this study provides vital information on the past land utilization priorities in the four cities, and comparatively proffers guidance on certain critical areas of focus for local, regional, and global future sustainable urban planning.

Quantifying the dynamics of sub-daily to seasonal hydrological interactions of Ganges river with groundwater in a densely populated city: Implications to vulnerability of drinking water sources

Groundwater resources in South Asian cities are facing immense stress due to over-extraction leading to environmental, social and economic instabilities. The perennial mega rivers of Himalayas form the lifeline for South Asia, underpinning food and water security for a large population both directly and indirectly through exchange with groundwater systems. The present study delineates the spatio-temporal variation in patterns and processes of sub-hourly to annual-scale hydrological exchanges between the Ganges and its adjoining highly exploited aquifer in a urban-peri urban reach. Multivariate statistical analyses established river water-groundwater interaction in this region with ~40% loading of first principal component, i.e river water during monsoon on the shallow aquifer. The part of the aquifer detached from the main confined aquifer show an influence of precipitation (the second principal component) with loading of ~90%. Again the part of the aquifer suffering infiltration of local surface water bodies show effect of precipitation with a second principal loading of ~80%. Fourier transformation is used in the hydrograph to remove influence of heavy urbanization on the hydrographs. This study proves that the phenomenon of infiltrating river water during monsoon plays a primary role in controlling aquifer storage although contaminating the aquifer simultaneously. However, during pre and post-monsoon the flow path reversal helps in maintaining river baseflow. Cross-correlation between the river and piezometric series show increased delay of pressure head propagation of the infiltrating river waterfront, with increasing distance. These observations are also substantiated by stable isotope signatures. The present study provides an understanding of potential groundwater vulnerability resulting from waste water and irrigational contamination through river water intrusion which would eventually lead the government to implement proper water and environmental management policies towards availability of long-term sustainable water resources for the residents.

Thermal Discomfort Levels, Building Design Concepts, and Some Heat Mitigation Strategies in Low-Income Communities of a South Asian City.

Heat stress provokes thermal discomfort to people living in semiarid and arid climates. This study evaluates thermal discomfort levels, building design concepts, and some heat mitigation strategies in low-income neighborhoods of Faisalabad, Pakistan. The outdoor and indoor weather data are collected from April to August 2016 using a weather station installed ad hoc in urban settings, and the 52 houses of the five low-income participating communities living in congested and less environment-friendly areas of Faisalabad. The discomfort index values, related to the building design concepts, including (i) house orientation to sunlight and (ii) house ventilation, are calculated from outdoor and indoor dry-bulb and wet-bulb temperatures. Our results show that although June was the hottest month of summer 2016, based on the monthly mean temperature of the Faisalabad region, the month of May produced the highest discomfort levels, which were higher in houses exposed to sunlight and without ventilation. The study also identifies some popular heat mitigation strategies adopted by the five participating low-income communities during various heat-related health complaints. The strategies are gender-biased and have medical, cultural/customary backgrounds. For example, about 52% of the males and 28% of the females drank more water during dehydration, diarrhea, and eye infection. Over 11% and 19% of the males and females, respectively, moved to cooler places during fever. About 43% of the males and 51% of the females took water showers and rested to combat flu (runny nose), headache, and nosebleed. The people did not know how to cure muscular fatigue, skin allergy (from a type of Milia), and mild temperature. Planting trees in an area and developing open parks with greenery and thick canopy trees can be beneficial for neighborhoods resembling those evaluated in this study.

Effect of COVID-19 Lockdown on Air Quality: Evidence from South Asian Megacities

Anthropogenic activities were greatly restricted in many South Asian cities during the COVID-19 (Coronavirus disease-2019) pandemic creating an opportunity to observe source reduction of air pollutants. This study analyzed the change in columnar nitrogen dioxide (NO2) and particulate matter (PM2.5, aerodynamic diameter ≤2.5 µm) in five megacities of South Asian countries (Delhi, Dhaka, Kathmandu, Kolkata, and Lahore) from April 1 - May 31 over the previous three years (2018-2020). The Dutch-Finnish Ozone Monitoring Instrument (OMI) provided satellite-based daily tropospheric columnar NO2 values for this study. Ground-based hourly PM2.5 data were collected from the World's Air Pollution: Real-time Air Quality Index Project. The study observed a decrease of tropospheric columnar NO2 in selected cities in 2020 compared to 2018 and 2019 from April 1 - May 31. The mean daily reading of PM2.5 was 36.56% and 45.44% less in Delhi; 12.67% and 23.46% less in Dhaka; in Kathmandu 28.32% and 37.42% less; in Kolkata 41.02% less in 2020 than 2018 and 34.08% less in 2019 during April 1 - May 31. The PM2.5 was 44.26% less in 2020 than in 2019 during April 9 - May 31 in Lahore. The daily mean difference in concentration during April 1 - May 31, 2018-2020 was significantly lower at α=0.01 level for both pollutants. Introducing appropriate mitigation measures would provide safer environments and reduce future air pollution in South Asian cities.

Evaluation of Urban Heat Island (UHI) Using Satellite Images in Densely Populated Cities of South Asia

Rapid Urbanization, and other anthropogenic activities, have amplified the change in land-use transition from green space to heat emission in built-up areas globally. As a result, there has been an increase in the land surface temperature (LST) causing the Urban Heat Island (UHI) effect, particularly in large cities. The UHI effect poses a serious risk to human health and well-being, magnified in large developing cities with limited resources to cope with such issues. This study focuses on understanding the UHI effect in Kathmandu Valley (KV), Delhi, and Dhaka, three growing cities in South Asia. The UHI effect was evaluated by analyzing the UHI intensity of the city with respect to the surroundings. We found that the central urban area, of all three cities, experienced more heat zones compared to the peri-urban areas. The estimated average surface temperature ranged from 21.1 ∘C in March 2014 to 32.0 ∘C in June 2015 in KV, while Delhi and Dhaka experienced surface temperature variation from 29.7 ∘C in June 2017 to 40.2 ∘C in June 2019 and 23.6 ∘C in March 2017 to 33.2 ∘C in March 2014, respectively. Based on magnitude and variation of LST, highly built-up central KV showed heat island characteristics. In both Delhi and Dhaka, the western regions showed the UHI effect. Overall, this study finds that the UHI zones are more concentrated near the urban business centers with high population density. The results suggest that most areas in these cities have a rising LST trend and are on the verge of being UHI regions. Therefore, it is essential that further detailed assessment is conducted to understand and abate the impact of the temperature variations.

Urban green spaces in Dhaka, Bangladesh, harbour nearly half the country’s butterfly diversity

AbstractCities currently harbour more than half of the world’s human population and continued urban expansion replaces natural landscapes and increases habitat fragmentation. The impacts of urbanisation on biodiversity have been extensively studied in some parts of the world, but there is limited information from South Asia, despite the rapid expansion of cities in the region. Here, we present the results of monthly surveys of butterflies in three urban parks in Dhaka city, Bangladesh, over a 3-year period (January 2014 to December 2016). We recorded 45% (137 of the 305 species) of the country’s butterfly richness, and 40% of the species detected are listed as nationally threatened. However, butterfly species richness declined rapidly in the three study areas over the 3-year period, and the decline appeared to be more severe among threatened species. We developed linear mixed effect models to assess the relationship between climatic variables and butterfly species richness. Overall, species richness was positively associated with maximum temperature and negatively with mean relative humidity and saturation deficit. Our results demonstrate the importance of urban green spaces for nationally threatened butterflies. With rapidly declining urban green spaces in Dhaka and other South Asian cities, we are likely to lose refuges for threatened fauna. There is an urgent need to understand urban biodiversity dynamics in the region, and for proactive management of urban green spaces to protect butterflies in South Asia.

Urban ecosystems and ecosystem services in megacity Dhaka: mapping and inventory analysis

Urban ecosystems and ecosystem services have received little research attention in South Asian countries where rapid urban development is currently problematic. We developed a typology of urban ecosystems and an inventory of current ecosystem services for Dhaka – the capital of Bangladesh. Our observations, surveys, analyses, and evaluation revealed a diversity of urban ecosystems including khal (canal), pond, wetland, cultivated land, park/rooftop garden, playground/field, open space/vacant plot, roadside trees, and graveyards. Important provisioning services included fruits, vegetables, fish, fodder, timber, fuelwood, and medicinal/ornamental plants. Regulating services included carbon sequestration and particulate matter removal by park and roadside trees, drainage service by khals and wetlands, and noise abatement by parks. Opportunities for recreation, fishing and sports, walk/exercise, inspirations for art and culture and religious values presented cultural services. Habitat services such as refugia for resident and migratory birds featured in parks, lakes, wetlands and trees on roadsides, playgrounds/fields, and graveyards. Evaluation of the states and values of urban ecosystems and ecosystem services are prerequisites to improving the wellbeing of urban communities particularly in Dhaka but more generally for other major cities in South Asia. Our findings will assist policy makers in sustainable urban ecosystem governance with possible implications for region-wide cooperation.

A Brief Review on Changes in Air Pollution Scenario over South Asia during COVID-19 Lockdown

In general, the lockdown to prevent the outbreak of COVID-19 pandemic has resulted in a better quality of air across the world. The concentrations of both particulate and majority of gaseous pollutants were decreased drastically due to total shutdown of outdoor activities in the initial phase. This has resulted in up to 50% reduction in the air quality index (AQI) over South Asian megacities. A significant reduction was observed over most polluted ranked cities in South Asia like Delhi (41%), Dhaka (16%), Kathmandu (32%), Colombo (33%) including Islamabad and Kabul. A major decrease was also observed in the gaseous pollutants like CO, NO2, and SO2. The strict lockdown provided an opportunity to the relevant authorities to reassess the large-scale transport and industrial sectors to avoid undue emissions of harmful pollutants. The present analysis suggests that there is a need of controlled emissions of air pollutants with reference to the lockdown values of `New Normal’, and to switch over to the cleaner fuel technology options at the earliest possible. There is a need to constitute an Inter-state agency to monitor trans-boundary and long-range transport of pollution across south Asia. Finally, a holistic approach for maintaining balance between `need and greed’ for energy and resource consumption is needed which can provide us the sustainable atmosphere and healthy air quality throughout the region.

Identity Negotiations among the Urban Youth of Ethnic Minority in South Asian Cities

Identity Negotiations among the Urban Youth of Ethnic Minority in South Asian Cities

Intergenerational Teaching-learning through Meditation and Smartphone Use Skill-knowledge Transfer between South Asian Grandparent-grandchild Dyads

ABSTRACT This article reports the impact of an intergenerational teaching-learning program (ITLP) of meditation and smartphone use on promoting social engagements for grandparents and attachment security for their young adult grandchildren. Grandparent-grandchildren dyads from two South Asian cities were randomized into intervention (IN1 = 86; IN2 = 78) and control groups (CN1 = 86; CN2 = 72). Grandparents’ scores on Lubben Social Network Scale-6 (LSNS-6) and grandchildren’s scores on Revised Adult Attachment Scale (RAAS) were assessed at pretest (TI) and posttest (T2). Intervention group grandparents had higher social engagements and grandchildren had lower attachment insecurities compared to the control dyad at T2. ITLP impact was moderately high (Cohen’s d range = 0.49–0.56, p≤.01) and T2 performance was better for grandmother-grandchild dyads, middle class, widowed grandparents and cohabiting dyads. ITLP attendance and home practice mediated the relationship between participant characteristics and outcomes. Actor-partner independence models indicated that attendance and home practice were interdependent and posttest increase in grandparents’ social network was positively associated with grandchildren’s attachment security at T2. The ITLP is a practical and useful program for intergenerational learning.