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In this paper, we analyzed two decadal long term (2003–2022) data of AOD and cloud parameters to understand the spatial and temporal variations in aerosol radiative characteristics over a highly polluted urbanized region of Northern India. The aerosol and cloud data were derived at spectral wavelength of 550 nm from the MODIS based Terra/Aqua satellites. Detailed AOD quantitative analysis considering monthly, seasonal and interannual changes was investigated in relation to cloud characteristics and zonal synoptic climatic disturbances. HYSPLIT back trajectory 5-day analysis was made to know the pathways of air masses ending at Delhi region of India. Moreover, we applied Student's t-test to mean Terra AOD and cloud properties to examine and further validate the relationship of aerosol-cloud interaction over the urban tropical Delhi zone close to Himalaya range of Northern India. Results indicated that AODs were found to be increased significantly (> 68%) during the 20 years period of 2003–2022, which might be accounted to continuously increased aerosol pollution in atmosphere. On an annual basis, mean Terra AOD exhibited an increasing trend of ~ 0.0009 per year, whereas seasonal mean AOD was observed to be maximum for winter (~ 0.96) and minimum for summer (~ 0.55), respectively. The correlation coefficient was highest (+ 0.73) between AOD and precipitable water vapor, whereas lowest (− 0.46) between AOD and cloud top pressure (CTP). The findings of AOD and cloud parameters have been compared with the earlier findings made on different Indian cities. [ABSTRACT FROM AUTHOR]

The efforts to encourage sustainable development have brought to attention the use of secondary materials in civil engineering applications. Global experimental data suggest that municipal solid waste (MSW) incineration bottom ash (IBA) can potentially replace natural aggregates in field applications. However, IBA is currently disposed in open dumps or sanitary landfills in India. Assessing contaminant leaching from IBA is crucial to ascertain its options for disposal or reuse. The current study analyzes the mineralogy, chemical constituents, organic content, and leaching of contaminants from IBA collected from two incineration plants in Delhi. The study takes into consideration the effect of particle size, liquid-to-solid (L/S) ratio, and pH on contaminant leaching. The experimental results revealed that the leaching concentration of contaminants and organic content of IBA decreases with an increase in particle size. A considerable influence of pH was noted on the leaching of all contaminants except chlorides, sulfates, and antimony. The results further indicate that IBA is suitable for disposal in non-hazardous waste landfills regardless of particle size at its intrinsic pH. However, it is recommended to dispose IBA in monofils as co-disposal with MSW in sanitary landfills can cause the pH of IBA to shift toward the acidic range, which may exacerbate the contaminant leaching from IBA. The comparison of leaching test results with international regulatory standards for reuse demonstrates that using IBA in unbound applications is feasible in paved roads and earthworks subjected to minimal infiltration of water. [ABSTRACT FROM AUTHOR]

This study examined within and cross-language relations, and specifically, the role of phonological awareness (PA) skills in reading among young Hindi-speaking children (L1) who were learning to read English (L2) in Delhi, India. Data was collected from 143 children in Grades 1 and 2 using measures validated for this population. The analyses examined the associations between L1 and L2 PA and decoding, both within and across the two languages. The results showed that PA skills within each language significantly predicted decoding in that language. Furthermore, there was evidence of cross-language transfer with Hindi PA significantly predicting English word reading even after controlling for English PA. English PA also significantly predicted Hindi decoding, however, these effects decreased once Hindi PA was added to the model. These findings emphasize the important role that both L1 and L2 PA plays in reading among emergent Hindi–English bilinguals. The theoretical and practical implications of these findings on literacy instruction in India are discussed. [ABSTRACT FROM AUTHOR]

Mobile banking liberates people from spatial and temporal constraints and delivers significant convenience but people are still hesitant to use mobile banking. The purpose of this study is to examine the most important factors influencing and impeding consumer adoption of mobile banking. This study uses Unified Theory of Acceptance and Use of Technology (UTAUT) and Technology Readiness (TR) as a theoretical basis and integrates it with cognitive resistance to propose a conceptual model for m-banking adoption in India. Data was collected from 536 mobile banking customers from Delhi/NCR, using convenience sampling and was analysed using structural equation modelling. The findings revealed that the impact of facilitating factors namely, performance expectancy, effort expectance, social influence, optimism and innovativeness on behavioural intention to use m-banking is much more than the impact of inhibiting factors namely, discomfort, insecurity and cognitive resistance and also that behavioral intention has a significant impact on adoption of m-banking. In examining the relationship between facilitating factors and behavioral intention, there is no substantial moderation impact of age groups. However, gender moderated the relationship between effort expectancy and behavioral intention, as well as the relationship between optimism and behavioral intention. This research would help policymakers to understand and overcome the reluctance and barriers of adoption and would result in ensuring more adoption of advanced technological channels. [ABSTRACT FROM AUTHOR]

Water is a prime necessity for the survival and sustenance of all living beings. Over the past few years, the water quality of rivers is adversely affected due to harmful wastes and pollutants. This ever-increasing water pollution is a big matter of concern as it deteriorating the water quality, making it unfit for any type of use. Recently, water quality modelling using machine learning techniques has generated a lot of interest and can be very beneficial in ecological and water resources management. However, they suffer many times from high computational complexity and high prediction error. The good performance of a deep neural network like long short-term memory network (LSTM) has been exploited for the time-series data. In this paper, a deep learning–based Bi-LSTM model (DLBL-WQA) is introduced to forecast the water quality factors of Yamuna River, India. The existing schemes do not perform missing value imputation and focus only on the learning process without including a loss function pertaining to training error. The proposed model shows a novel scheme which includes missing value imputation in the first phase, the second phase generates the feature maps from the given input data, the third phase includes a Bi-LSTM architecture to improve the learning process, and finally, an optimized loss function is applied to reduce the training error. Thus, the proposed model improves forecasting accuracy. Data comprising monthly samples of different water quality factors were collected for 6 years (2013–2019) at several locations in the Delhi region. Experimental results reveal that predicted values of the model and the actual values were in a close agreement and could reveal a future trend. The performance of our model was compared with various state of the art techniques like SVR, random forest, artificial neural network, LSTM, and CNN-LSTM. To check the accuracy, metrics like root mean square errors (RMSE), the mean absolute error (MAE), mean square error (MSE), and mean absolute percentage error (MAPE) have been used. Experimental analysis is carried out by measuring the COD and BOD levels. COD analysis reveals the MSE, RMSE, MAE, and MAPE values as 0.015, 0.117, 0.115, and 20.32, respectively, for the Palla region. Similarly, BOD analysis indicates the MSE, RMSE, MAE, and MAPE values as 0.107, 0.108, 0.124, and 18.22, respectively. A comparative analysis reveals that the proposed model outperforms all other models in terms of the best forecasting accuracy and lowest error rates. [ABSTRACT FROM AUTHOR]

This paper is an analysis of the subjective well-being of women relative to men in low-income urban households in India. Education and employment are pathways to greater financial well-being which is presumably of great salience to poor populations. However, either or both of these may increase aspirations. The social norms that restrict the autonomy of women may mute the impact of education and employment in a way that does not happen to men. To address this hypothesis, the paper uses primary data from a survey of over 1000 respondents across slums in Delhi. The paper finds that education and employment does reduce the well-being of women relative to men. We show that these gender varying correlations are robust to omitted variables bias. [ABSTRACT FROM AUTHOR]

This paper is an analysis of the subjective well-being of women relative to men in low-income urban households in India. Education and employment are pathways to greater financial well-being which is presumably of great salience to poor populations. However, either or both of these may increase aspirations. The social norms that restrict the autonomy of women may mute the impact of education and employment in a way that does not happen to men. To address this hypothesis, the paper uses primary data from a survey of over 1000 respondents across slums in Delhi. The paper finds that education and employment does reduce the well-being of women relative to men. We show that these gender varying correlations are robust to omitted variables bias. [ABSTRACT FROM AUTHOR]

The studies on escalators have mainly reported the walking speeds of passengers or their passenger handling capacity. Theoretical capacity is reported as a constant value for a given escalator speed, but is never achieved in the field. This creates practitioners' dilemma regarding augmentation of the facility as some capacity will always remain available even under high passenger flows. This paper explores the issue and proposes a reference capacity for examining the effective utilisation of the escalator. The capacity is estimated with stand-only and stand-walk etiquette. The data available in the literature and from the video graphed information at metro stations in Delhi, India is used to examine the effect of step occupancy, walking speed of passengers and their proportion in the flow. It is observed that walking-factor and step occupancy is higher in developing countries. Walking factor is estimated as 0.70–0.74 and step occupancy as 0.80–1.70. The occupancy on walking side is estimated as one passenger per two steps as compared to the reported value of one per three steps. This indicates that the flow conditions on escalators in India are more restrictive as compared to other countries. The comparison of field capacity with reference capacity has indicated that the reference capacity can be used for the evaluation of actual flow condition on escalators. [ABSTRACT FROM AUTHOR]

For nearly two years, a persistent foam cover has been observed during the post-monsoon season in the Yamuna River beneath the barrage near Okhla in Delhi, India. This affair has been a matter of public concern now, after the gigantic appearance of foam in November 2021, as the visibility of foam has awakened people's environmental 'conscience' over the 'concealed' chemical pollution. The mechanisms of agents responsible for foaming in rivers, particularly surfactants and phosphates, have received wide attention in the dynamic community of river pollution. Many studies in the past, around the globe, have evidently provided different rationales behind the dense foam formation in rivers, yet the Concerned Govt. Authorities have highlighted the cause of foam formation in the river Yamuna is associated with the presence of detergents and phosphates as foaming agents. Despite this, an aperture with copious unaccounted factors or underlying agents still exists to rationalize the foam formation and persistence. In this article, we outline these unaccounted factors which might be responsible for the foam formation and stabilization and give indications for future research directives towards the emergence of studies regarding the dense foam formation in river Yamuna. [ABSTRACT FROM AUTHOR]

COVID-19 have significant impact on travel behaviour and greenhouse gases (GHG), especially for the most affected city in India, Mumbai metropolitan region (MMR). The present study attempts to explore the risk on different modes of transportation and GHG emissions (based on change in travel behavior) during peak/non-peak hours in a day by an online/offline survey for commuters in Indian metropolitan cities like MMR, Delhi and Bengaluru. In MMR, the probability of infection in car estimated to be 0.88 and 0.29 during peak and non-peak hour, respectively, considering all windows open. The risk of infection in public transportation system such as in bus (0.307), train (0.521), and metro (0.26) observed to be lower than in private vehicles. Furthermore, impact of COVID-19 on GHG emissions have also been explored considering three scenarios. The GHG emissions have been estimated for base (3.83–16.87 tonne), lockdown (0.22–0.48 tonne) and unlocking (2.13–9.30 tonne) scenarios. It has been observed that emissions are highest during base scenario and lowest during lockdown situation. This study will be a breakthrough in understanding the impact of pandemic on environment and transportation. The study shall help transport planners and decision makers to operate public transport during pandemic like situation such that the modal share of public transportation is always highest. It shall also help in regulating the GHG emissions causing climate change. [ABSTRACT FROM AUTHOR]

There is substantial evidence that due to perceived childcare obligations, mothers are disadvantaged in labor markets. To what extent can childcare support ameliorate such a disadvantage? To answer this question, we ran a CV experiment in a large Indian city and examined whether indicating access to childcare support in a CV may offset the motherhood penalty associated with labor market entry. We randomly varied motherhood, as well as access to childcare in CVs sent to online applications for service sector jobs in Delhi. Indicating motherhood on a CV led to a 57% or 20 percentage point reduction in callback rates for interviews as compared to non-mothers. A simple indication of access to childcare support offsets the motherhood penalty by 20% or 4 percentage points. We interpret the findings in the Indian context and with respect to potential sources of discrimination. [ABSTRACT FROM AUTHOR]

Bacterial panicle blight (BPB) caused by Burkholderia glumae (BG) has become significantly more prevalent in the rice-growing regions of North India. Based on virulence screening and in vitro quantification of toxoflavin, the BG strains were classified as hyper- (BG1 and BG3), moderate- (BG2, BG4, BG6, BG8, and BG9), and hypo- (BG5, BG7, and BG10) virulent. Plant inoculation assays with cell-free culture filtrate revealed strains with higher toxoflavin-producing ability had higher virulence. Based on 16S rRNA sequence, 6 isolates from Uttar Pradesh were grouped in clad C1; whereas, clad C2 exhibited 4 isolates, two each from Delhi and Uttar Pradesh. Strain BG1 being the most virulent Indian strain from Uttar Pradesh was further profiled for 11 tox genes. We found all the 11 tox genes present in strain BG1. In toxRABCDE cluster, all tox genes showed high similarity to B. glumae BGR1 except toxB, whereas in toxFGHIJ cluster toxF, toxG, toxH and toxI shared maximum similarity to B. glumae 336gr-1. tox genes of BG1 exhibited homology as well as divergence with B. gladioli. The domain prediction and protein association network analysis indicated the possible involvement of tox genes in the toxoflavin biosynthesis. As per our knowledge, this is the first report in India on characterization of tox genes cluster in B. glumae. Altogether, our study unravels a reliable method for identifying and characterizing B. glumae using tox genes and its relationship with disease production. [ABSTRACT FROM AUTHOR]

Stubble burning is an emerging environmental issue in Northern India, which has severe implications for the air quality of the region. Although stubble burning occurs twice during a year, first during April–May and again in October–November due to paddy burning, the effects are severe during October–November months. This is exacerbated by the role of meteorological parameters and presence of inversion conditions in the atmosphere. The deterioration in the atmospheric quality can be attributed to the emissions from stubble burning which can be perceived from the changes observed in land use land cover (LULC) pattern, fire events, and sources of aerosol and gaseous pollutants. In addition, wind speed and wind direction also play a role in changing the concentration of pollutants and particulate matter over a specified area. The present study has been carried out for the states of Punjab, Haryana, Delhi, and western Uttar Pradesh to study the influence of stubble burning on the aerosol load of this region of Indo-Gangetic Plains (IGP). In this study, the aerosol level, smoke plume characteristics, long-range transport of pollutants, and affected areas during October–November from year 2016 to 2020 were examined over the Indo-Gangetic Plains (Northern India) region by the satellite observations. By MODIS-FIRMS (Moderate Resolution Imaging Spectroradiometer-Fire Information for Resource Management System) observations, it was revealed that there was an increase in stubble burning events with the highest number of events being observed during the year 2016 and then a decrease in the number of events in subsequent years from 2017 to 2020. MODIS observations revealed a strong AOD gradient from west to east. The prevailing north-westerly winds assist the spread of smoke plumes over Northern India during the peak burning season of October to November. The findings of this study might be used to expand on the atmospheric processes that occur over northern India during the post-monsoon season. The pollutant, smoke plume features, and impacted regions of biomass-burning aerosols in this region are critical for weather and climate research, especially given the rising trend in agricultural burning over the previous two decades. [ABSTRACT FROM AUTHOR]

Methane is an important greenhouse gas, which constitutes minimum 90% of automotive grade compressed natural gas (CNG) used in India. The use of CNG as automotive fuel has been implemented in almost all major tier I to tier III cities of the country. Delhi, the capital city of India, has world largest CNG-fuelled public transport system. The cylinders fitted to the CNG-fuelled vehicles are required to be subjected to hydrostatic stretch test every 3 years at Government of India approved CNG cylinder testing stations, as mandated under Rule 35 of Gas Cylinders Rules, 2016. During the testing of cylinders, CNG present in the cylinders are discharged in the atmosphere at the degassing point of CNG testing stations. This study estimates annual methane emissions from the CNG cylinder testing stations of Delhi. The annual average methane emission from the CNG cylinder testing stations of Delhi was found to be 30.8 tons during the year 2019. The uncertainties in the emission estimate are also identified and discussed. [ABSTRACT FROM AUTHOR]

The quality of air that we breathe is one of the more serious environmental challenges that the government faces all around the world. It is a matter of concern for almost all developed and developing countries. The National Air Quality Index (NAQI) in India was first initiated and unveiled by the central government under the Swachh Bharat Abhiyan (Clean India Campaign). It was launched to spread cleanliness, and awareness to work towards a clean and healthy environment among all citizens living in India. This index is computed based on values obtained by monitoring eight types of pollutants that are known to commonly permeate around our immediate environment. These are particulate matter PM10; particulate matter PM2.5; nitrogen dioxide; sulfur dioxide; carbon monoxide; lead; ammonia; and ozone. Studies conducted have shown that almost 90% of particulate matters are produced from vehicular emissions, dust, debris on roads, and industries and from construction sites spanning across rural, semi-urban, and urban areas. While the State and Central governments have devised and implemented several schemes to keep air pollution levels under control, these alone have proved inadequate in cases such as the Delhi region of India. Internet of Things (IoT) offers a range of options that do extends into the domain of environmental management. Using an online monitoring system based on IoT technologies, users can stay informed on fluctuating levels of air pollution. In this paper, the design of a low-price pollution measurement kit working around a dust sensor, capable of transmitting data to a cloud service through a Wi-Fi module, is described. A system overview of urban route planning is also proposed. The proposed model can make users aware of pollutant concentrations at any point of time and can also act as useful input towards the design of the least polluted path prediction app. Hence, the proposed model can help travelers to plan a less polluted route in urban areas. [ABSTRACT FROM AUTHOR]

This paper presents a scenario for the spatial variation of the fundamental frequency of the sediment deposits above the basement and the corresponding amplification as well as the average spectral amplification in different frequency bandwidths for the National Capital Territory Delhi (the capital of India). The exposed central quartzite ridge and the Yamuna River channel are responsible for very large spatial variations of the fundamental frequency in the eastern part of the National Capital Territory Delhi. At 20% of the considered sites, a good match is obtained between the fundamental frequency computed numerically using available S-wave velocities to a certain depth and their extrapolation and that obtained experimentally. The computed fundamental and dominant frequencies reveal that both medium-rise (5–10 storey) and high-rise (> 10 storey) buildings in the western part and medium-rise buildings lying in the localities east of or very near to the Yamuna River may suffer heavy to very heavy damage due to the occurrence of the double resonance phenomenon. Furthermore, 1–2-storey buildings lying on the weathered exposed quartzite rock may also suffer heavy damage during local earthquakes because of the occurrence of double resonance. The possible reasons behind the lack of earthquake damage to the Qutab Minar, the tallest brick masonry minaret in the world, over the last 800 years may be the nonoccurrence of double resonance and almost no amplification in the low frequency range. There are two localities in the western part of the National Capital Territory Delhi, namely Kanganheri-Chhawla and Buradi, wherein all sorts of buildings are highly vulnerable to earthquake damage. For the closed Chhatarpur Basin and a semiclosed basin to its northeast, formed due to exposed quartzite rock, three-dimensional (3D) simulations are required to predict the characteristics of basin-generated surface waves and their focusing effects in the Chhatarpur Basin. The average spectral amplification map developed for the 0–10 Hz bandwidth depicts a range of 2.25–4.82 in the National Capital Territory Delhi and may be directly used to transfer the estimated seismic hazard at basement to the free surface. [ABSTRACT FROM AUTHOR]

The present study investigates the reduction in nitrogen dioxide (NO2) levels using satellite-based (Sentinel-5P TROPOMI) and ground-based (Central Pollution Control Board) observations of 2020. The lockdown duration, monthly, seasonal and annual changes in NO2 were assessed comparing the similar time period in 2019. The study also examines the role of atmospheric parameters like wind speed, air temperature, relative humidity, solar radiation and atmospheric pressure in altering the monthly and annual values of the pollutant. It was ascertained that there was a mean reduction of ~ 61% (~ 66.5%), ~ 58% (~ 51%) in daily mean NO2 pollution during lockdown phase 1 when compared with similar period of 2019 and pre-lockdown phase in 2020 from ground-based (satellite-based) measurements. April month with ~ 57% (~ 57%), summer season with ~ 48% (~ 32%) decline and an annual reduction of ~ 20% (~ 18%) in tropospheric NO2 values were observed (p < 0.001) compared to similar time periods of 2019. It was assessed that the meteorological parameters remained almost similar during various parts of the year in 2019 and 2020, indicating a negligent role in reducing the values of atmospheric pollution, particularly NO2 in the study area. It was concluded that the halt in anthropogenic activities and associated factors was mainly responsible for the reduced values in the Delhi conglomerate. Similar work can be proposed for other pollutants to holistically describe the pollution scenario as an aftermath of COVID-19-induced lockdown. [ABSTRACT FROM AUTHOR]

Yamuna is one of the main tributaries of the river Ganga and passes through Delhi, the national capital of India. In the last few years, it is considered one of the most polluted rivers of India. We carried out the analysis for the physiochemical and biological conditions of the river Yamuna based on measurements acquired at Palla station, Delhi during 2009–19. For our analysis, we considered various physicochemical and biological parameters (Dissolved Oxygen (DO) Saturation, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Alkalinity, Total Dissolved Solids (TDS), and Total Coliform. The water stats of river Yamuna at Palla station were matched with Water Standards of India, United Nations Economic Commission for Europe (UNECE), and World Health Organization (WHO). Maximum changes are observed in DO saturation and total coliform, while BOD and COD values are also seen higher than the upper limits. Total alkalinity rarely meets the minimum standards. TDS is found to be satisfactory as per the standard limit. The river quality falls under Class D or E (IS2296), Class III or IV (UNECE), and fails to fulfill WHO standards for water. After spending more than 130 million USD for the establishment of a large number of effluent treatment plants, sewage treatment plants, and common effluent treatment plants, increasing discharges of untreated sewage, partially treated industrial effluents and reduced discharge of freshwater from Hathnikund are causing deterioration in water quality and no major improvements are seen in water quality of river Yamuna. [ABSTRACT FROM AUTHOR]

The extreme temperature events are a concern in recent years due to climate variability particularly in India as there is an increase in the temperature intensity, frequency, and duration. This study represents stationary temperature-duration-frequency (TDF) analysis over two mega cities in India Delhi (north) and Bengaluru (south) using the daily maximum temperatures at meteorological stations for the period 1969–2016 observed by India Meteorological Department (IMD).The interannual variability of maximum temperature and the maximum daily recorded value indicates the increasing trend in both the cities. The study investigates the extreme analysis of the maximum temperature using two distributions, i.e., Gumbel's Extreme Value Type 1 (GEVT) and Log Pearson Type III (LPT), for return periods 2, 5, 10, 25, 50, and 100 years at both the locations and the positive temporal trend is observed. The TDF curves were build using annual maximum temperature values for total 8 durations (different days) of 48 years analyzed and results show the increasing trend of maximum temperature at lower duration and high return period values. The TDF is also used for prediction of the maximum temperature for the 2 hottest years in India, i.e., 2012 and 2015, and it is comparable with the observed maximum temperature. Similarly, the predictions for 11 years, i.e. 2006 to 2016, over both the cities are simulated using both the GEVT-I and LPT-III and the models have better potential skill in predicting the extreme maximum temperature. These results can be useful for the sectors like health, energy, agriculture, urban management, and ecology management and can help the policy decision makers and disaster managers in the mitigation and adoption steps to face the extreme temperature disaster at city scale. [ABSTRACT FROM AUTHOR]

Lockdown was imposed by the Indian government in the month of March 2020 as an early precaution to the COVID-19 pandemic which obstructed the socio-economic growth globally. The main aim of this study was to analyse the impact of lockdown (imposed in March and continued in April 2020) on the existing air quality in three megacities of India (Delhi, Mumbai and Kolkata) by assessing the trends of PM10 and NO2 concentrations. A comparison of the percentage reduction in concentrations of lockdown period with respect to same period in year 2019 and pre-lockdown period (February 14–March 24) was made. It was observed from the study that an overall decrease of pollutant concentrations was in the ranges of 30–60% and 52–80% of PM10 and NO2, respectively, in the three cities during lockdown in comparison with previous year and pre-lockdown period. The overall decrease in concentrations of pollutants at urban sites was greater than the background sites. Highest decline in concentrations of PM10 were observed in Kolkata city, followed by Mumbai and Delhi, while decline in NO2 was highest in Mumbai. Results also highlighted that capital city Delhi had the worst air quality amongst three cities, with particulate matter (PM10) being the dominant pollutant. Although COVID-19 has significantly affected the human life considering the mortality and morbidity, lockdowns imposed to control the pandemic had significantly improved the air quality in the selected study locations, although for the short amount of period. [ABSTRACT FROM AUTHOR]

Identification of the most relevant parameters of a sustainable transportation system is regarded as a significant choice that influences the success of policy-related intervention to improve efficiency. A hybrid-based approach has been used to analyze the data in multiple steps to improve accuracy and objectivity. In the first step, evidence on social, economic, and environmental indicators was formed for each opinion and then combined. The second step proposed a mathematical framework to treat indecision on the indicators collected from multiple sources, viz. expert and public opinion survey, models, and actual measurement during pre- and post-implementation stages of the Odd–Even scheme. By setting up, a reliability function and consistency index are used to evaluate and rank the Odd–Even transportation scheme introduced by the Government of Delhi. A case study in South Delhi's surrounding areas has been examined to demonstrate the proposed hybrid approach and evaluate the parameters in terms of the index. The result shows that the indicators like trip cost, trip time, safety and security, user's satisfaction, congestion level, parking demand, and fuel consumption affected positively by 1766.6, 22.9, 283.3, 19.1, 187.5, 200, and 17.2 percent, respectively, after the implementation of the scheme. The overall increase in the index was found as 28.2%, which favors the "Odd–Even" scheme as a sustainable transportation measure in Delhi. [ABSTRACT FROM AUTHOR]

Background & aim: In the wake of COVID-19, organizations all over India have closed their premises and shifted to work from home policy to curb the further spread of the virus. This has led to increased stress and anxiety among employees, which explicably affects their satisfaction with life. Thus, the present study analyses the effect of COVID-19 induced stressors (role overload, lifestyle choices, family distraction, and occupational discomfort) on employees' distress levels and job performance. Subsequently, the impact of such distress and job performance on the employees' life satisfaction is analyzed during the lockdown period. Methodology: Data was collected from 433 working professionals of private and public organizations in the Delhi and NCR region of India during India's third and fourth phase of lockdown via a survey, which was distributed online. Partial least squares structural equation modelling was applied first to establish the validity of this study's model (measurement model validity) and subsequently test the hypothesized relationships in the model (structural model). Results: The COVID-19 induced stressors, i.e., role overload, lifestyle choices, and occupational discomfort, were significant predictors of distress during the lockdown. It has been found that role overload and change in lifestyle choice did not significantly affect job performance. Family distraction, occupational discomfort, and distress were significant in impacting job performance, with distress being the most significant one. During the COVID-19 pandemic, life satisfaction has reduced due to a significant increase in distress levels and lowered job performances. [ABSTRACT FROM AUTHOR]

The increasing frequency of heat waves (HW) in many parts of the world is emerging as one of the climatic vulnerabilities across the world resulting in elevated thermal stress and high mortality. With increase in HW intensity, frequency and duration at global level, India has seen several major HW events in the last decade. HW conditions have mostly been studied by analysing ground-based observations; however, this approach lacks information on spatial variability at the local scale, which is not adequate to identify HW risk and vulnerability hotspots. In this study, gridded analysis of spatio-temporal variability of HW indices has been carried out by utilising freely available Moderate Resolution Imaging Spectrometer (MODIS) Land Surface Temperature (LST) data on Google Earth Engine (GEE) platform in the Indo-Gangetic Plains of India. HW indices to analyse duration, frequency and intensity of HW have been identified and further computed on a grid size of 10 km*10 km area. HW risk and vulnerability hotspot in the study region have been identified by spatial modelling of HW indices, LULC change and population density. The HW risk and vulnerability hotspot layer identified NCT Delhi and its surrounding region at the highest risk of HW with high vulnerability. A strong positive correlation of variability of HW indicators with increasing built-up shows that built-up surfaces affect strongly the HW conditions. [ABSTRACT FROM AUTHOR]

The goal of this work is to assess the sensitivity of the Weather Research and Forecasting (WRF) model to various microphysical and land surface model parameterizations, as well as their effectiveness in capturing a radiation fog event that occurred on 15–16 February 2000 over Delhi in the Indo-Gangetic Plain (IGP). Fog forecasting using state-of-the-art mesoscale models is challenging due to limitations in understanding of atmosphere-land surface feedbacks and fog microphysics. Fog can have adverse effects because of low visibility on transport and aviation but affects positively agriculture and forestry by absorbing fog water. In India, the IGP is particularly susceptible to fog during the winter months of December, January, and February (DJF). To reach the goal in this work, preliminary investigation is carried out with five model experiments centered at Delhi for testing model sensitivity to nesting and gravitational settling of fog. The non-nested domain fares better at fog forecasting as compared to the nested domain. Accounting for the gravitational settling of fog droplets in the model further enhances model performance. Thereafter, to assess the model sensitivity to parameterization schemes, 40 model suite combinations with five microphysical (MP) schemes, two planetary boundary layer (PBL) schemes, and four land surface model (LSM) schemes are compared. The validations for fog formation, development, and dissipation are performed using observations collected over Safdarjung airport in Delhi. We conclude that the Thompson MP scheme, along with the Mellor-Yamada Nakanishi-Niino (MYNN 2.5) PBL and Rapid Update Cycle (RUC) LSM scheme, is able to capture the radiation fog event better than other schemes, and it is critical for evaluating the life cycle of radiation fog. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and phenolic compounds (PCs) are persistent organic compounds. Contamination of these potentially toxic organic pollutants in soils and sediments is most studied environmental compartments. In recent past, studies were carried out on PAHs, OCPs and PCs in various soils and sediments in India. But, this is the first study on these pollutants in soils and sediments from an urbanized river flood plain area in Delhi, India. During 2018, a total of fifty-four samples including twenty-seven each of soil and sediment were collected and analyzed for thirteen priority PAHs, four OCPs and six PCs. The detected concentration of ∑PAHs, ∑OCPs and ∑PCs in soils ranged between 473 and 1132, 13 and 41, and 639 and 2112 µg/kg, respectively, while their concentrations in sediments ranged between 1685 and 4010, 4.2 and 47, and 553 and 20,983 µg/kg, respectively. PAHs with 4-aromatic rings were the dominant compounds, accounting for 51 and 76% of total PAHs in soils and sediments, respectively. The contribution of seven carcinogen PAHs (7CPAHs) in soils and sediments accounted for 43% and 61%, respectively, to ∑PAHs. Among OCPs, p, p'-DDT was the dominant compound in soils, while α-HCH was found to be dominated in sediments. The concentrations of ∑CPs (chlorophenols) were dominated over ∑NPs (nitrophenols) in both the matrices. Various diagnostic tools were applied for the identification of their possible sources in soil and sediments. The observed concentrations of PAHs, OCPs and PCs were more or less comparable with the recently reports from various locations around the world including India. Soil quality guidelines and consensus-based sediment quality guidelines were applied for the assessment of ecotoxicological health effect. [ABSTRACT FROM AUTHOR]

This paper builds upon the theoretical framework advanced by the growing literature on vulnerability. The paper explores how vulnerability to HIV/AIDS applies to young women living in the slum areas of New Delhi and Hyderabad. This circumscription of scope is based on a study on AIDS awareness levels in these two Indian cities conducted during summer of 2006. Using a qualitative approach, the paper offers insightful narratives from a sample of 26 women about their cultural and socio-economic circumstances with reference to HIV/AIDS. The excerpts from these women give a poignant view of their precarious circumstances with reference to lack of female autonomy, economic vulnerability, low AIDS awareness, and lack of access to pertinent information about HIV. The female youth were highly susceptible to the double bind of age and gender based hierarchies present in the patriarchal Indian social system. [ABSTRACT FROM AUTHOR]

The National Capital Region of India (NCR Delhi) receives around 26 rainy days with majority of short duration high intensity rainfall events. Yet, the city faces severe waterlogging during south-west monsoon, and shortage of water in other seasons due to rapid urbanization and changing hydrological flow patterns. In an uncertain scenario, where spatiotemporal variability of rainfall at local scale is not very well understood, a location-specific robust model applicable for the megacity through interpretation of parameter estimates will improve understanding of extreme rainfall pattern with duration. Identification of the best-fit statistical model for prediction of short duration extreme events is done and parameters of the model are evaluated for different durations. The study finds that the 2-parameter gamma distribution and 3-parameter generalized extreme value (GEV) predict similar return levels of extreme intensity for short durations and short return periods. The shape parameter in GEV and shape and scale parameters in gamma explain the extreme quantile in the distribution responsible for prediction of high magnitude events. The more generic gamma model is robust and applicable at local scale, with pronounced shape parameter variations across durations (1–11.534, 2–8.264, 3–6.609 h). It is concluded that the knowledge of hourly variation in extreme rainfall events will help in informed decision making in this acutely water-stressed region of the world. Highlights: Short duration extreme rainfall events are frequent in semi-arid urban regions and characterization of these storms is important. The extreme rainfall pattern characteristics is defined through the parameter estimates of shape and scale of gamma distribution. Within 1 h duration rainfall events pattern, the higher shape factor identifies storms in a more wet regime (α-14.05) than the mean (α-11.534), while the lower shape factor identifies dry regime (α-9.018). The 4 h and 6 h events have the lowest shape factor and high scale factor, implying variation, and unpredictability. Short duration storms have the potential to cause flash floods, the hydrological insights provided by this study will be useful in similar geographical regions. [ABSTRACT FROM AUTHOR]

This paper describes the process of urbanization and land use change in the urban ecosystems of the National Capital Region (NCR) of Delhi, India. Two types of land use change are considered--from natural to urban and from agricultural to urban. Both types are explained in terms of economic variables known to be drivers of change. A panel data method was used, and economic variables were combined with GIS-based information on land use change during 1986-2004 for 11 administrative units of the NCR. The results suggest that investment in the construction sector plays a major role in converting the land from natural to urban areas, while differences in land productivity seems to be the major driver for change from agricultural to urban uses. [ABSTRACT FROM AUTHOR]

Urban transport has serious problems that are symptoms of the general process of rapid urbanization and environmental degradation. Policymakers in general and urban economists in particular have paid little attention to public transport system pricing leading to the absence of a financially viable, self-supporting urban transport system. In this paper, we report a partial equilibrium model developed by us, which captures transport tax reforms in the presence of certain transport externalities. Our theoretical model shows that the question of public transport subsidies to reduce congestion and provide quality transport services depends on three factors: (a) the extent to which such subsidies induce people to switch from private transport to public transport; (b) if the price elasticity of current users of public transport is higher, there may be a sharp rise in public transport ridership as a reaction to increased subsidies, which will have an undesirable effect; and (c) there is the danger that subsidies will cause a loss in productive efficiency. The numerical model of our paper for Delhi shows that the cross price elasticity of public transport demand with respect to the price of private transport is significant (0.63) in the off-peak period whereas the same in the peak period is somewhat low (0.16) and the combined effect of these elasticities will result in a considerable modal shift in favour of bus transport demand (19%) if the price of public transport were to be subsidized and private transport were to be priced optimally. Even without subsidy, the modal shift will be significant (18%), if the under-priced private transport modes are optimally priced keeping the current bus prices constant. This paper shows that there will be significant welfare gains in both these scenarios. [ABSTRACT FROM AUTHOR]

Air pollution has become a growing problem in megacities and large urban areas through out the globe, and transportation is recognized as the major source of air pollution in many cities, especially in developing countries. Contribution of automobiles is reported in the range of 40 to 80% of the total air pollution. The challenge facing megacities is how to reduce the adverse environmental impacts and other negative effects of transportation without giving up the benefits of mobility. The dilemma becomes most pressing under conditions of rapid urban growth, which is likely to increase travel demand significantly. The paper is aimed at understanding the problem of vehicular pollution vis-a-vis ambient air quality for a highly traffic affected megacity, Delhi, wherein, the contribution of transport sector was estimated to be as high as 72%. An effort has been made to review and evaluate the benefits (in terms of improved air quality) of the technological interventions/policies adopted for vehicular pollution control in Delhi. It also highlights the outcome of the efforts and suggests further improvements thereon. The importance of public participation and awareness are also discussed. The paper focuses on deriving the benefits of the implementation of management strategies, supported by scientific and technical data/interpretation, so that the people can realize and participate in the government's endeavor for clean city drive in a more effective manner. [ABSTRACT FROM AUTHOR]

The present paper is an attempt to examine the trend in the level of environmental pollution in Delhi and measures taken to control it. The data have been analyzed from various secondary sources of data. The analysis reveals that rapid population growth continues to be a matter of concern as it has manifold effects, one of the most important being environmental pollution. Densely populated and rapidly growing Delhi mega city is often entombed in a pall of pollution from vehicles, sewage and liquid wastes generated by human settlement and uncontrolled pollution from industries. The recent pollution control measures taken by central government reduced the environmental pollution up to some extent. [ABSTRACT FROM AUTHOR]

Gerontological literature in India has primarily focused on the macro processes of aging. Studies on population aging have examined themes such as health outcomes, financial arrangements and alternate caregiving arrangements in different parts of India. Though these studies have highlighted important issues surrounding aging, nonetheless the more micro perspectives such as the everyday processes of aging have remained under explored in India. In fact, studies on perceptions of aging have indicated that generally older Indians associate aging with disengagement, withdrawal and death. While studies on older Indians have projected them as detached and accepting decline, nonetheless this sort of a generalization is not true for all older Indians. Drawing from in-depth qualitative interviews and detailed narratives this study examines the lived experiences of aging in urban Delhi, India to understand the complex processes of growing old. Findings from the study suggest that older adults in urban Delhi are developing their own "selves" to determine their process of aging. Adopting a socio-gerontological lens and building on the Successful Aging model and the Dramaturgical Theory this study will demonstrate how the experience of aging and intergenerational relationships are changing in urban settings. Finally the study will also indicate how gender dynamics are shaped in later ages among older Indians in the urban context. [ABSTRACT FROM AUTHOR]

In many instances the sulphide mineralization is associated with quartz vein-related hydrothermal alteration zone. The syntectonic quartz veins display preferred orientation as their intrusion is controlled by normal stress (σn) acting across the foliation/fracture planes and the fluid pressure (Pf) of the quartz veins. The Pf and paleostress (ϕ = tectonic stress ratio) are measurable by using stereoplot and 3D Mohr plot. We have determined the above parameters from the quartz veins in the Cu–Pb–Zn mineralization belt of South Delhi terrane, NW India. The mineralization occurs in the mica schist and metabasalt. The rock types show three phases of folding (F1–F3), greenschist facies metamorphism and multiple phases of granite intrusion. Attitude of 170 quartz veins have been measured, the NE–SW direction is the most prominent. Though some of the quartz veins show a cross-cutting relationship, we have treated them broadly synchronous. Stereoplot shows a girdle distribution pattern with an elliptical void area at the centre and σ1σ2 plane strikes N52° E. Further, σ1 = 120°/75°, σ2 = 052°/07°, and σ3 = 323°/07° indicate that maximum extension was NW–SE. The θ2 = 12°, θ3 = 40°. R ' = 0.95, ϕ = 0.90 indicate high value for R ' leading to dilation of wide range of fractures and the high ϕ value suggesting uniaxial extension. 3D Mohr plot indicates that Pf fluctuated between σ2 < Pf < σ1. Since sulphide mineralization is related to quartz vein intrusion, we interpret similar stress field for mineralization. [ABSTRACT FROM AUTHOR]

Understanding of seismicity and seismotectonics of Delhi and adjoining areas is essential as these areas lie in the seismic zone IV and are geologically confined to the Delhi Fold Belt (DFB), juxtaposed to the Himalayan Frontal Thrust Fold Belt. Owing to the set-up, seismicity in this area is ascribed to the Himalayan Thrust System and activation of DFB Fault Systems. Considerably improved instrumental seismic monitoring in this area and data analysis had resolved three regions of pronounced seismicity that lie close to Sonepat, Rohtak and western part of the NCT Delhi, attributed to activation of various portions of the fault systems of the DFB. Based on seismic telemetry network data, the seismicity pattern analysis revealed that the Mahendragarh Dehradun Sub-Surface Fault (MDSSF) and Delhi Sargodha Ridge (DSR) are the two major zones of structural importance for the nucleation of seismicity in this region. These revelations were corroborated with the fault plane solution of the earthquakes. The dominant mechanism in nucleation of seismicity in DFB is the thrust with minor strike slip. The seismicity and seismotectonics of Delhi and adjoining areas endemic to activation of DFB is reviewed and presented in this paper. [ABSTRACT FROM AUTHOR]

general neural network based methodology that has the potential to replace the computationally-intensive site-specific seismic analysis of structures is proposed in this paper. The basic framework of the methodology consists of a feed forward back propagation neural network algorithm with one hidden layer to represent the seismic potential of a region and soil amplification effects. The methodology is implemented and verified with parameters corresponding to Delhi city in India. For this purpose, strong ground motions are generated at bedrock level for a chosen site in Delhi due to earthquakes considered to originate from the central seismic gap of the Himalayan belt using necessary geological as well as geotechnical data. Surface level ground motions and corresponding site-specific response spectra are obtained by using a one-dimensional equivalent linear wave propagation model. Spectral acceleration values are considered as a target parameter to verify the performance of the methodology. Numerical studies carried out to validate the proposed methodology show that the errors in predicted spectral acceleration values are within acceptable limits for design purposes. The methodology is general in the sense that it can be applied to other seismically vulnerable regions and also can be updated by including more parameters depending on the state-of-the-art in the subject. [ABSTRACT FROM AUTHOR]

The aim of this paper is to forecast the level of car ownership in Delhi, the capital city of India up to the year 2021. The in-sample forecasting is based on estimation of logistic and Gompertz distributions using annual data of car ownership from the year 1965-66 to 2000-2001 under three alternative saturation levels viz. 25, 33 and 50 cars per 100 persons, the saturation levels being evolved from household size. It is observed that, by the year 2020-21, the car ownership level will touch the mark of 14 and 17 cars per 100 persons in Delhi under the saturation levels 25 and 50 respectively. This study will be useful for planners, policy makers and researchers in the area of transport, energy and road for realistic view of the subject and for the planning of appropriate strategy. [ABSTRACT FROM AUTHOR]

This paper describes the development of artificial neural network (ANN) based carbon monoxide (CO) persistence (ANNCOP) models to forecast 8-h average CO concentration using 1-h maximum predicted CO data for the critical (winter) period (November–March). The models have been developed for three 8-h groupings of 10 p.m. to 6 a.m., 6 a.m. to 2 p.m. and 2–10 p.m., at two air quality control regions (AQCRs) in Delhi city, representing an urban intersection and an arterial road consisting heterogeneous traffic flows. The result indicates that time grouping of 2–10 pm is dominantly affected by inversion conditions and peak traffic flow. The ANNCOP model corresponding to this grouping predicts the 8-h average CO concentrations within the accuracy range of 68–71%. The CO persistence values derived from ANNCOP model are comparable with the persistence values as suggested by the Environmental Protection Agency (EPA), USA. This work demonstrates that ANN based model is capable of describing winter period CO persistence phenomena. [ABSTRACT FROM AUTHOR]

Air pollution is one of the major environmental problems in India, affecting health of thousands of ‘urban’ residents residing in mega cities. The need of the day is to evolve an ‘effective’ and ‘efficient’ air quality management plan (AQMP) encompassing the essential ‘key players’ and ‘stakeholders.’ This paper describes the formulation of an AQMP for mega cities like Delhi in India taking into account the aforementioned key ‘inputs.’ The AQMP formulation methodology is based on past studies of Longhurst et al., ( Atmospheric Environment, 30, 3975–3985, 1996); Longhurst & Elsom, ((1997). Air Pollution-II, Vol. 2 (pp. 525–532)) and Beatti et al., ( Atmospheric Environment, 35, 1479–1490, 2001). Further, the vulnerability analysis (VA) has been carried out to evaluate the stresses due to air pollution in the study area. The VA has given the vulnerability index (VI) of ‘medium to high’ and ‘low’ at urban roadways/intersections and residential areas, respectively. [ABSTRACT FROM AUTHOR]

A number of policy measures have been activated in India in order to control the levels of air pollutants such as particulate matter, sulphur dioxide (SO2) and nitrogen dioxide (NO2). Delhi, which is one of the most polluted cities in the world, is also going through the implementation phase of the control policies. Ambient air quality data monitored during 2000 to 2003, at 10 sites in Delhi, were analyzed to assess the impact of implementation of these measures, specifically fuel change in vehicles. This paper presents the impact of policy measures on ambient air quality levels and also the source apportionment. CO and NO2 concentration levels in ambient air are found to be associated with the mobile sources. The temporal variation of air quality data shows the significant effect of shift to CNG (Compressed Natural Gas) in vehicles. [ABSTRACT FROM AUTHOR]

fter a brief and pointed recapitulation of the main issues of Demuth, Chaudhary and Keller's article, Memories of me. Comparisons from Osnabrück (Germany) and Delhi (India) students and their mothers (doi:), alternative or complementary approaches to the investigation of 'doing' memory and self in different cultural contexts are outlined in a sketch of three interrelated proposals. These proposals turn around a) 'contemporaneousness of the non-contemporaneous' ( Gleichzeitigkeit des Ungleichzeitigen) and the analysis of 'cultural hybrids', b) 'indigenous concepts of memory and self' and c) 'memory and self in actual cultural practice'. [ABSTRACT FROM AUTHOR]

Atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) in Delhi were evaluated to study particulate PAHs profiles during the different seasons of 2003. Samples of urban suspended particulate matter were collected during January 2003 to December 2003 at three locations (Okhla, Dhaulakuan and Daryaganj), using a high volume sampler provided with glass fiber filters. Samples were analyzed using the gas chromatography technique. The annual average concentrations of total PAHs were found as 1,049.3 ng/m3 at Okhla, 1,344.37 ng/m3 at Daryaganj, and 1,117.14 ng/m3 at Dhaulakuan. The seasonal average concentrations were found to be maximum in winter and minimum during the monsoon season. Principal Component Analysis (PCA) of the data was also carried out and the results indicate that diesel and gasoline driven vehicles are the principal sources of PAHs at all the three sites under investigation. Other sources might come from stationary combustion sources such as cooking fuel combustion and industrial emission. [ABSTRACT FROM AUTHOR]

In this study, efforts are made to improve the simulation of heavy rainfall events over National Capital Region (NCR) Delhi during 2010 summer monsoon, using additional observations from automatic weather stations (AWS). Two case studies have been carried out to simulate the relative humidity, wind speed and precipitation over NCR Delhi in 48-h model integrations; one from 00UTC, August 20, 2010, and the other from 00UTC, September 12, 2010. Several AWS installed over NCR Delhi in the recent past provide valuable surface observations, which are assimilated into state-of-the-art weather research and forecasting (WRF) model using the three-dimensional variational data assimilation (3DVAR). The quality of background error statistics (BES) is a key component in successful 3DVAR data assimilation in a mesoscale model. In this study, the domain-dependent regional background error statistics (RBS) are estimated using National Meteorological Center method in the months of August and September 2010 and then compared with the global background error statistics (GBS) in the WRF model. The model simulations are analyzed and validated against AWS and radiosonde observations to quantify the impact of RBS. The root mean square differences in the spatial distributions of precipitation, relative humidity and wind speed at the surface showed significant differences between both the global and regional BES. Similar differences are also observed in the vertical distributions along the latitudinal cross section at 28.5°N. Model-simulated fields are analyzed at five different surface stations and one upper air station located in NCR Delhi. It is found that in 24-h model simulation, the RBS significantly improves the model simulations in case of precipitation, relative humidity and wind speed as compared to GBS. [ABSTRACT FROM AUTHOR]

The study deals with the combined contribution of polycyclic aromatic hydrocarbons (PAHs) and metals to health risk in Delhi soils. Surface soils (0-5 cm) collected from three different land-use regions (industrial, flood-plain and a reference site) in Delhi, India over a period of 1 year were characterized with respect to 16 US Environmental Protection Agency priority PAHs and five trace metals (Zn, Fe, Ni, Cr and Cd). Mean annual ∑PAH concentrations at the industrial and flood-plain sites (10,893.2 ± 2826.4 and 3075.4 ± 948.7 μg/kg, respectively) were ~15 and ~4 times, respectively, higher than reference levels. Significant spatial and seasonal variations were observed for PAHs. Toxicity potentials of industrial and flood-plain soils were ~88 and ~8 times higher than reference levels. Trace metal concentrations in soils also showed marked dependencies on nearness to sources and seasonal effects. Correlation analysis, PAH diagnostic ratios and principal component analysis (PCA) led to the identification of sources such as coal and wood combustion, vehicular and industrial emissions, and atmospheric transport. Metal enrichment in soil and the degree of soil contamination were investigated using enrichment factors and index of geoaccumulation, respectively. Health risk assessment (incremental lifetime cancer risk and hazard index) showed that floodplain soils have potential high risk due to PAHs while industrial soils have potential risks due to both PAHs and Cr. [ABSTRACT FROM AUTHOR]

In this study, soil response was carried out for the Greater Delhi region. A folded Proterozoic formation was identified as Delhi ridge, passes through its central part along SSW-NNE direction, and appears to be a main geomorphic feature for the study area. The Delhi ridge is an exposed quartzite rock of about 10-100 m wide and ~25 km long with gentler dipping both toward east and west. We have considered the exposed part as an outcrop side near the ridge axis and the dipping area as rigid base away from the ridge axis for ground motion study during the occurrence of the 25 November 2007 earthquake with magnitude M 4.3 (Richter scale) that occurred at Delhi-Haryana State boundary. The degree of shaking was very strong and reported major cracks in the buildings near the epicenter area. We have studied the soil response parameters at the surface level, considering horizontally stratified soil layers above rigid base. The equivalent linear method was used for soil response analysis at 25 sites in Greater Delhi area. The peak amplification factors vary from 3.2 to 5.9 and peak resonance frequency varies from 1.2 to 5.3 Hz. The correlation among the peak amplification factor ( A) and frequency ( f) was empirically established as A = 0.36 f + 3.60. Increasing peak amplification factor was found at sites with increasingly thicker alluvium deposit with lower frequency contains ground motion and vice versa. Seismic zoning map was also reconstructed for peak amplification factors and predominant periods for the study area for the mitigation purposes of earthquake damage. The average shear wave velocity up to 30 m soil depth is also obtained for site classification. The average velocity to 30 m [ $$ \overline{{V_{\text{s}} }} (30) $$] is a widely used parameter for classifying sites for predicting their potentiality to amplify seismic shaking. A lower value [ $$ \overline{{V_{\text{s}} }} (30) $$] thus yields a more conservative estimate of ground motion, which generally increases as $$ \overline{{V_{\text{s}} }} (30) $$decreases. Present estimate of $$ \overline{{V_{\text{s}} }} (30) $$varies from 315 to 419 m/s. In this study, we have identified two site classes C and D, as per National Earthquake Hazard Reduction Program. The city planner or engineers can directly use these data for site-specific assessment during retrofitting of the existing structure, demolition of the old buildings and design a new structure to avoid major destruction of the buildings due to future earthquake. [ABSTRACT FROM AUTHOR]

Present study deals with the statistical analysis of long-term ground level ozone (O) trend and the influence of meteorological variables on its variation over Delhi, India. Daily mean and maximum of O and meteorological data, obtained from India Meteorological Department, were arranged for the period of 9 years (1998-2006). Based on the preliminary correlation study of all the data with O, six variables viz. daily maximum temperature, daily average relative humidity, dew point, wind speed, visibility, and total sunshine were selected. Classical additive time series decomposition technique was used to obtain seasonally adjusted long-term trend. To analyze the masking effect of meteorology, adjustment was made using Kolmogorov-Zurbenko filters followed by stepwise regression analysis to the smoothed series of O maximum and meteorological variables, which showed that long-term trend was independent of sunshine duration. Results indicate a significant increasing trend with annual increase of 1.13 % for O mean and 3 % for O maximum. Annual deseasonalized trend for seasonal cycle shows bimodal oscillations. About 43 % of O variation was explained by the selected meteorological factors and rest of variation attributed to factors like emission of precursor gases, pollutant transport, policy changes, etc. Among the three tested regression models, performance of Model 2 with variable temperature, wind speed, and visibility was found to be best that resulted in lowering of O trend. Large variability (23 %) was explained by the variable visibility depicted that the emission of primary pollutants not only provides the precursor gases but also control the local photochemical reactions. [ABSTRACT FROM AUTHOR]

The leguminous flora of Delhi comprises 78 Papilionoideae, 24 Caesalpinioideae and 24 Mimosoideae species; 80 of them are perennials. Five types of imparipinnate and two types of paripinnate compound leaves were observed in the species. The paripinnate leaves are bipinnate in 25 species (mostly mimosoid) and bifoliate in two species. The imparipinnate leaves were trifoliate or multifoliate in 59 papilionoid species and multifoliate in 16 caesalpinioid species; four of the papilionoid species produced leafletted and tendrilled unipinnate leaves. Leaves were bifacially simple in 22 species, simple with ectopic terminal growth in one species and simple tendril in one species. Twenty-one species (mostly mimosoid) were devoid of stipules. In 82 species stipules were small and free. Stipules were large and lobed in 17 species and large and adnate in four species. Two species of Caesalpinioideae produce compound leaf-like stipules. All four stipule phenotypes of 126 species corresponded with stipular phenotypes observed in wild type, coch, st and coch st genotypes of the model legume P. sativum. The seven leaf phenotypes observed in 126 species corresponded with phenotypes expected among combinations of uni ( uni- tac), af, ins, mfp and tl mutants of P. sativum and sgl1, cfl1, slm1 and palm1 mutants of M. truncatula, also an IRL model legume. All the variation in leaf and stipule morphologies observed in the leguminous flora of Delhi could be explained in terms of the gene regulatory networks already revealed in P. sativum and M. truncatula. It is hypothesized that the ancestral gene regulatory networks for leaves and stipules produced in Leguminosae were like that prevalent in P. sativum. [ABSTRACT FROM AUTHOR]

Semi-continuous measurements of organic carbon (OC) and elemental carbon (EC) and continuous measurements of black carbon (BC) and PM aerosols were conducted simultaneously during the winter period of 2010-2011 at Delhi, one of the polluted urban megacities in western part of the Indo-Gangetic Basin region. The average mass concentrations of OC, EC, BC and PM were about 54 ± 39, 10 ± 5, 12 ± 5 and 210 ± 146 μg m, respectively. Contribution of total carbonaceous aerosol mass to PM mass was found to be ~46 %. Average OC/EC ratio was found to be 5 ± 2 during the study period, suggesting the presence of secondary organic aerosols in the atmosphere over Delhi. Estimated mean secondary organic aerosol mass concentration was found to be 25 μg m and varied between 14.6 (February) and 37.0 μg m (December). A diurnal variation of OC and EC shows lower values during the day time and higher during the morning and night, which are highly associated with the corresponding variability in mixing layer heights. OC and EC were also found to be significantly correlated ( r = 0.71) to each other, indicating their common sources. Concentrations of OC and EC were about 45 and 13 % higher during weekdays than weekends, respectively. Higher OC (67 %) and EC (53 %) were observed in the late evening during weekdays than those on weekends, which could be due to different emission sources during these two periods. The night/day ratio of EC and OC was found to be larger than 1.0, suggesting the relative accumulation of EC and OC near the surface at night hours. [ABSTRACT FROM AUTHOR]

The present study proposed to investigate the atmospheric distribution, sources, and inhalation health risks of polycyclic aromatic hydrocarbons (PAHs) in a tropical megacity (Delhi, India). To this end, 16 US EPA priority PAHs were measured in the inhalable fraction of atmospheric particles (PM; aerodynamic diameter, ≤10 μm) collected weekly at three residential areas in Delhi from December 2008 to November 2009. Mean annual 24 h PM levels at the sites (166.5-192.3 μg m) were eight to ten times the WHO limit. Weekday/weekend effects on PM and associated PAHs were investigated. ΣPAH concentrations (sum of 16 PAHs analyzed; overall annual mean, 105.3 ng m; overall range, 10.5-511.9 ng m) observed were at least an order of magnitude greater than values reported from European and US cities. Spatial variations in PAHs were influenced by nearness to traffic and thermal power plants while seasonal variation trends showed highest concentrations in winter. Associations between ΣPAHs and various meteorological parameters were investigated. The overall PAH profile was dominated by combustion-derived large-ring species (85-87 %) that were essentially local in origin. Carcinogenic PAHs contributed 58-62 % to ΣPAH loads at the sites. Molecular diagnostic ratios were used for preliminary assessment of PAH sources. Principal component analysis coupled with multiple linear regression-identified vehicular emissions as the predominant source (62-83 %), followed by coal combustion (18-19 %), residential fuel use (19 %), and industrial emissions (16 %). Spatio-temporal variations and time-evolution of source contributions were studied. Inhalation cancer risk assessment showed that a maximum of 39,780 excess cancer cases might occur due to lifetime inhalation exposure to the analyzed PAH concentrations. [ABSTRACT FROM AUTHOR]

Cities across the globe are considered as major anthropogenic sources of greenhouse gases (GHG), yet very few efforts has been made to monitor ambient concentration of GHG in cities, especially in a developing country like India. Here, variations in the ambient concentrations of carbon dioxide (CO) and methane (CH) in residential, commercial, and industrial areas of Delhi are determined from fortnightly daytime observations from July, 2008 to March, 2009. Results indicate that the average daytime ambient concentration of CO varied from 495 to 554 ppm in authorized residential areas, 503 to 621 ppm in the slums or jhuggies in the unauthorized residential areas, 489 to 582 ppm in commercial areas, and 512 to 568 ppm in industrial areas with an average of 541 ± 27 ppm. CH concentration varied from 652 to 5,356 ppbv in authorized residential areas, 500 to15,220 ppbv in the unauthorized residential areas, 921 to 11,000 ppbv in the commercial areas, and 250 to 2,550 ppbv in the industrial areas with an average of 3,226 ± 1,090 ppbv. A low mid-afternoon CO concentration was observed at most of the sites, primarily due to strong biospheric photosynthesis coupled with strong vertical mixing. [ABSTRACT FROM AUTHOR]

The study addresses disaster risks in Delhi through a resilience approach. It utilizes the Climate Disaster Resilience Index (CDRI) tool, which assesses disaster resilience from five dimensions: physical, social, economic, institutional, and natural. Each dimension comprises 5 parameters, and each parameter consists of 5 variables. The study is carried out in the nine revenue districts of Delhi and reveals that East Delhi is least resilient and New Delhi is most resilient. The CDRI analysis in East Delhi points out the urgent need to focus on key parameters such as housing and land use, population, intensity and frequency of natural hazards, ecosystem services, and land use in natural terms. On the other hand, New Delhi is the most resilient due to all five dimensions, where most significant parameters responsible for its high resilience are housing and land use, population, income, employment, intensity and frequency of natural hazards, ecosystem services, and land use in natural terms. In addition, the overall results of all nine districts show an inverse relationship between resilience score and population density. For example, districts with higher population density show low resilience and vice versa. Moreover, districts located on hazard-prone areas show low resilience. For example, East Delhi and North East Delhi scored low resilience because they both are situated on the Yamuna flood catchment areas. The study further develops key suggestions that are required to address disaster risk in all nine districts of Delhi and discusses future implications of CDRI to address city's vulnerability. The approach's distinctness is reflected through its consideration of micro-level diversities and presents some implications to resilience. [ABSTRACT FROM AUTHOR]