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Near-fault ground motions (NFGM) may have a significant component of the long period velocity pulse (LPVP) due to the directivity effect. The structures subjected to such ground motions are prone to experience large displacements. In this paper, the damage potential of such motions is compared with NFGM (without LPVP) and far-field motions in terms of seismic demand (inter-storey drift and inelastic displacement). Due to the lack of site-specific recorded NFGM, the synthetic ground motions are generated and used in this study. For this purpose, first the bedrock motions are obtained through stochastic simulation approach in which the Specific Barrier Model (SBM) is used as source spectrum and then these motions are transferred to the ground surface using one-dimensional ground response analysis. In order to obtain the NFGM with pulse, the bedrock motions are superimposed with the LPVPs and then transferred to the ground surface. To illustrate, the case of a ten-storey reinforced concrete (RC) building is considered in Delhi region (India) which falls under the seismic zone-IV. The main finding of this study is the observation that the NFGM with LPVP impose almost double seismic demand compared to the NFGM without LPVP, specially for the structures lying in the velocity-region of the response spectrum. In this study, the effect of depth of bedrock on seismic demand is highlighted and recommended to be included in the design seismic demand of NFGM. [ABSTRACT FROM AUTHOR]

Open waste burning is a significant contributor to air pollution in urban cities. The contribution includes sources from local and centralized waste burning. This paper focuses on the air quality changes in the surrounding regions of the Bhalswa landfill in the north-west part of Delhi, India, where a fire broke out accidentally in the landfill from 20 April 2022 to 8 May 2022. Bhalswa landfill is one among the three major landfills in Delhi, and during the waste burning, PM2.5 shows a maximum average concentration of about 107.32 and 338 µg/m3 for PM10. The average PM2.5 concentration increment was around 45–55%, and for PM10, it was 40–50% during the fire. Apart from particulate matter, fumes generated during open waste burning emit gaseous and toxic substances. Dispersion of pollutants was less during low (< 3 m/s) and calm winds (< 1 m/s) and more during high winds (> 3 m/s). The correlation value (R2) of gaseous pollutants with PM2.5 was significant and exhibited a moderate correlation (R2 around 0.5–0.6). It is high time for residents, government authorities and various other stack holders to be aware and implement policies and adopt technologies for segregation and processing. Identifying potential reuse of waste in energy and volume reduction forms should be encouraged to avoid further accidents/incidents related to open waste burning. The study's outcomes indicate the potential changes that occurred in regional air quality during the open waste burning in a short period. [ABSTRACT FROM AUTHOR]

Delhi's need for pure water is growing with its growing population. Along with the need for drinking water, useful sewage treatment is much needed. Another immense problem that the city faces is air pollution that causes health problems to the local community mainly caused by energy traditional plants. The patent Natural Biological System (NBS) developed by Ayala Water and Ecology offered Delhi and many other locations around the globe a practical, on-site method for the simultaneous purification of soil, water, and air with a negative carbon footprint. The current paper describes how those systems were applied to the on-ground situation after an extensive environmental survey that was conducted to identify the needs and difficulties characterizing the city. The solutions provided to Delhi are an example of how urban eras can benefit from the NBS system improving their ecosystem and supporting better and healthier life for their residents. [ABSTRACT FROM AUTHOR]

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 Paleoproterozoic Jahaj–Govindpura Formation of the Raialo Group of Delhi supergroup, India exposes volcanic and volcaniclastics rock at multiple stratigraphic levels and hence, provides a unique scope for the study of volcaniclastics of varying rheology and their bearing on the tectono-magmatic setting of the basin. From a detailed field study in three spatially disparate sections, associated sedimentary facies types and textural evidences such as clast annealing, deformation in pumice fragments, eutaxitic foliation and shattered crystals, the volcaniclastics are documented as pyroclastic flow (VLC 1), welded tuff (VLC 2), clast-/matrix-supported boulder pyroclastic conglomerate (VLC 3), and pyroclastic fall deposits (VLC 4). Whereas, VLC 1 and VLC 2 are identified as subaqueous, VLC 3 and VLC 4 are grouped under subaerial categories. The facies distribution of volcaniclastics and eastward paleocurrent motif from associated sedimentary facies is indicative of proximal-distal relationship varying between subaerial to sub-marine depositional settings. From collation and comparison of available geochemical data (major, trace element, and REE) of volcanic rock and new geochemical data generated from volcaniclastics under the present study, it is inferred that the source magma was more basic (low SiO2 and high MgO) resembling tholeiitic to calc-alkaline island-arc source composition while a more intermediate to felsic composition is posited for the volcaniclastics. Considering the ca-1876 Ma time frame of the basin and a subduction-related magmatic character for the volcaniclastics, a possible Orosirian subduction margin, related to the 'Columbia' supercontinent, in the vicinity of the Bayana sub-basin in North Delhi fold belt is suggested. Highlights: Primary subaerial to subaquous volcaniclastics described from Paleoproterozoic Bayana sub-basin, North Delhi Fold Belt, India. Unequivocal petrological features allowed subaerial and subaquous emplacement of volcaniclastics. Depending on associated sedimentary facies and paleocurrent motif a proximal-distal relationship established between different volcaniclastic facies. Whereas volcanics register tholeiitic to calc-alkaline composition, a more intermediate to felsic composition is inferred for the volcaniclastics. From geochemical signature, an overall compressional tectonic set-up is suggested with riftogenic Bayana basin a part of it. It is argued that in terms of tectonic and depositional setting, the Bayana basin shares a common geological history with contemporary basins in North China Craton. [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]

Landfill leachate forms when waste-inherent water and percolated rainfall transfer are highly toxic, corrosive, acidic, and full of environmental pollutants. The release of leachate from municipal solid waste (MSW) landfill sites poses a severe hazard to human health and aquatic life. This study examined the impact of leachate from Delhi's Ghazipur landfill on the nearby groundwater quality. Analysis of leachate samples was done to determine various parameters such as total dissolved solids (TDS), hardness, alkalinity, electrical conductivity, pH, BOD5, COD, nitrate, sulphate, chloride and iron, and presence of coliform bacteria. Significant dissolved elements (22,690–34,525 mg/L) were observed in the samples, indicated by the high conductivity value (1156–1405 mho/cm). However, a stable pH range (6.90–7.80) of leachate samples was observed due to high alkalinity concentrations between 2123 and 3256 mg/L. The inverse distance weighing (IDW) interpolation tool from QGIS 3.22.7 developed spatial interpolated models for each parameter across the Ghazipur area. The IDW interpolated graphs of various parameters over the whole study area confirmed these contaminations. In addition, leachate and groundwater samples were physio-chemically analyzed, and temporal fluctuation in landfill waste has also been studied. The temporal fluctuation results showed that when heat is produced, transmitted, and lost throughout the waste system, the maximum temperature position fluctuates over time. The findings of this study highlight the critical importance of landfill management in reducing groundwater contamination from MSW leachate. [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]

Emissions reductions from automotive vehicles are significant in protecting the environment. This study presents the development of new Indian motorcycle driving cycles (IMDC-1 & IMDC-2) based on the maximum speed and average speed of micro-trips. Time-speed data were collected using popular make motorcycles fitted with GPS on four different routes in Delhi-National Capital Region (NCR). The new IMDC cycles are comparable to WMTC when comparing the driving cycle parameters; however, they differ significantly from WMTC with a higher rate of acceleration and decoration. The fuel economy of new cycles was lower with higher CO and HC with insignificant change in NOx emissions compared to WMTC. The higher emissions with fuel penalty may be due to the higher rate of acceleration and deceleration experienced by the vehicles on Indian roads. Compared to WMTC, the IMDC cycles were found severe and very close to on-road driving patterns on comparing the driving cycle parameters; this indicates that the new cycles represent the real-world driving patterns experienced by vehicles in India. The new WMTC cycles can estimate realistic emissions factors that will support policymakers to form a new framework to reduce vehicular emissions to protect the environment. [ABSTRACT FROM AUTHOR]

It is currently unclear how river restoration based on hydro-geometrical modifications, dredging, and creating a barrier instead of its removal on a river would affect the water quality in urban rivers. This work attempts to fill this gap in our understanding by simulating the water quality of a highly critical 22-km-long Delhi stretch of river Yamuna in terms of DO, BOD, and total coliform after the implementation of these river restoration measures. Four scenarios were conceptualized based on these restoration measures and water quality simulated. These are: scenario I: simulate the impact of varying the width uniformly for all reaches of the study stretch on the water quality, scenario II: simulate the impact of increased depth by controlled dredging. Scenario III (a) closing the ITO barrage gate and then simulating river water quality from Wazirabad barrage to ITO barrage and (b) closing the ITO barrage and simulation of water quality from ITO barrage to Okhla barrage. Results reveal that the water quality improved significantly in scenario I and scenario II. Scenario III did not yield desirable results in terms of water quality improvement. To the best of the author's knowledge, this is the first attempt involving river morphometry changes using the QUAL2k model for the Delhi stretch of river Yamuna. [ABSTRACT FROM AUTHOR]

The role of urban forests in carbon capture and sequestration has been reviewed in a global context. An interpretive analysis was carried out using normalized difference vegetation index (NDVI) and allometric relationships in 5 cities of India, viz. Navi Mumbai, Nagpur, Bengaluru, Leh and Delhi, to evaluate the economic importance of urban green spaces in sequestrating carbon emissions and mitigating severe climatic impacts. NDVI maps were prepared using data from Landsat 7 and Landsat 8 satellite sensors. Bengaluru showed highest carbon sequestration (141.83 MT), and carbon sequestration in the city of Leh was comparatively very low (1.51 MT) as it is a cold desert with a very low urban forest cover. The valuation of urban green spaces in the selected cities was done by using market price method (MPM), value transfer method (VTM), and social cost of carbon method (SCC). The carbon sequestration valuation ranged from 55 to 5164 million$ for estimation using MPM and from 69.69 to 6537.15 million $ for SCC, whereas for VTM it ranged from 1575.06 to 147,736.94 million INR. The SCC approach used for valuation showed the highest cost of CO2 sequestered, while the MPM provided with the lowest value for all the five cities. Highest carbon sequestration and valuation values were observed in Bengaluru followed by Delhi. This study also points to the need of developing region-specific allometric relationships for better accuracy in quantifying carbon sequestration potential and associated economic value of urban forests. [ABSTRACT FROM AUTHOR]