Browsing by Author "Ramesh P. Singh"

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3D Stochastic Simulation of Rockfall Mechanism and Mitigation in the Batseri Zone
(Springer Science and Business Media Deutschland GmbH, 2025) Vishnu Himanshu Ratnam Pandey; Ashutosh Kainthola; Vikas Yadav; Jagadish Kundu; Paolo Mazzanti; Ramesh P. Singh; T. N. Singh
On 25 July 2021, a deadly rockfall at Batseri (Himachal Pradesh), India, killed 9 tourists and completely destroyed a crucial Bailey Bridge. The present study primarily focuses into the geomorphological and engineering geological attributes of the Batseri Rockfall dynamics. Extreme weathering phenomenon, adversely orientated joints, and abnormally high precipitation in the valley might have evoked the doomed incident. The work combines field study, structural analysis, and 3D stochastic assessment to ascertain the triggers, and trajectory of the rockfall. Runout distance, bounce height, kinetic energy, and velocity of the falling blocks with varying geometry and sizes have also been calculated. The results have been used to test the efficiency of rockfall barriers with different configurations and combinations to safeguard the affected strategically important road. These results can aid in mitigating the rockfall damage, effectively and economically. The simulation of potential blocks destroying the Bailey Bridge forms an important section of this research, and will assist in identification of suitable locations for new bridge instalment at Baspa River. Moreover, this work is perhaps the first of its kind to undertake the rigid body stochastic analysis for understanding the rockfall mechanism in such a large scale. The results discussed in the paper will be of use to understand similar events across the Himalayan terrains and develop policy for hazard mitigation. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.
Declining groundwater and its impacts along Ganga riverfronts using combined Sentinel-1, GRACE, water levels, and rainfall data
(Elsevier B.V., 2024) Ashwani Raju; Ramesh P. Singh; Praveen Kumar Kannojiya; Abhinav Patel; Saurabh Singh; Mitali Sinha
The Indo-Gangetic Plains (IGP) in northern India are vast alluvial tracts with huge shallow aquifers, densely populated and agriculturally productive regions. In the last few decades, IGP has been facing water scarcity driven by erratic monsoon dynamics, anthropogenic activity, and hydroclimatic variability. In urban centers, continuous groundwater withdrawal leads to high stress, affecting surface deformation and a threat to buildings and infrastructures. An attempt has been made to explore the possible linkage and coupling between groundwater level, hydroclimatic variables, and subsidence in the Central Ganga Plains (CGP), in Varanasi metropolis using the combined multisensory multitemporal data, Sentinel-1 (2017–2023), GRACE (2003–2023), groundwater levels (1998–2023), and precipitation (2002–2023). Long-term hydrological response in the CGP shows continuous depletion (14.6 ± 5.6 mm/yr) in response to precipitation variability. Results show spatiotemporal variations between GWS, and precipitation estimate with nonlinear trend response due to associated inter-annual/inter-seasonal climate variability and anthropogenic water withdrawal, specifically during the observed drought years. The significant storage response in the urban center compared to a regional extent suggests the potential impact of exponentially increasing urbanization and building hydrological stress in the cities. The implications of reducing storage capacity show measured land subsidence (∼2–8 mm/yr) patterns developed along the meandering stretch of the Ganga riverfronts in Varanasi. The groundwater level data from the piezometric supports the hydroclimatic variables and subsidence coupling. Considering the vital link between water storage, food security, and socioeconomic growth, the results of this study require systematic inclusion in water management strategies as climate change seriously impacts water resources in the future. © 2024
Elevated black carbon concentrations and atmospheric pollution around singrauli coal-fired thermal power plants (India) using ground and satellite data
(MDPI AG, 2018) Ramesh P. Singh; Sarvan Kumar; Abhay K. Singh
The tropospheric NO2 concentration from OMI AURA always shows high concentrations of NO2 at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the Indo-Gangetic Plain (IGP) and the Himalayan foothills, hav emerged as an important subject to estimate the effects of deposition and atmospheric warming of BC on the accelerated melting of snow and glaciers in the Himalaya. For the first time, this study reports BC concentrations and aerosol optical parameters near dense coal-fired power plants and open cast coal mining adjacent to the east IGP. In-situ measurements were carried out in Singrauli (located in south-east IGP) at a fixed site about 10 km from power plants and in transit measurements in close proximity to the plants, for few days in the month of January and March 2013. At the fixed site, BC concentration up to the 95 µgm−3 is observed with strong diurnal variations. BC concentration shows two maxima peaks during early morning and evening hours. High BC concentrations are observed in close proximity to the coal-fired TPPs (>200 µgm−3), compared to the outside domain of our study region. Co-located ground-based sunphotometer measurements of aerosol optical depth (AOD) show strong spatial variability at the fixed site, with AOD in the range 0.38–0.58, and the highest AOD in the range 0.7–0.95 near the TPPs in transit measurements (similar to the peak of BC concentrations). Additionally, the Angstrom exponent was found to be in the range 0.4–1.0 (maximum in the morning time) and highest in the proximity of TPPs (~1.0), suggesting abundance of fine particulates, whereas there was low Angstrom exponent over the surrounding coal mining areas. Low Angstrom exponent is characterized by dust from the unpaved roads and nearby coal mining areas. MODIS derived daily AOD shows a good match with the MICROTOPS AOD. The CALIPSO derived subtypes of the aerosol plot shows that the aerosols over Singrauli region are mainly dust, polluted dust, and elevated smoke. The preliminary study for few days provides information about the BC concentrations and aerosol optical properties from Singrauli (one of the NO2 hotspot locations in India). This preliminary study suggests that long-term continuous monitoring of BC is needed to understand the BC concentrations and aerosol optical properties for better quantification and the estimation of the emission to evaluate radiative forcing in the region. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.
Geomorphological and mineralogical analysis of the lunar Robertson crater
(Elsevier Ltd, 2025) Ashwani Raju; Saraah Imran; Jiwantika Kumari; Ankit Kumar; Ramesh P. Singh
This study provides a comprehensive overview of the lunar Robertson crater of Copernican period located on the far side of the moon using multi-sensor satellite observations from combined Chandrayaan-I M3, LROC WAC Global Geomorphology and SELENE DTM mosaics. The analysis shows development of dynamic features, distribution of minerals, and topographic features during the crater formation. The crater preserves a complex geological evolution based on the mineralogical heterogeneity and distinct geomorphological features (such as accumulated melt flow at the crater floor, topographic undulations etc.) observed in a radial symmetry, which suggest formation through high energy impact processes. The detailed investigation of melt pool topography at the crater floor, highlights the formation and subsequent modifications of the transient cavity developed during simple to complex crater transition after the impact. The mineral species identified using the RELAB spectral library through the ‘spectral hourglass’ workflow show a distinct distribution, with Mg-spinel and olivine-rich lithologies concentrated in the central peak, while pyroxenes dominate the crater floor and surrounding rock rings. This pattern shows a complex mineral distribution, likely excavated from different depths as a result of the impact event. The dynamics of crater formation show a diameter respectively of 4.36 km and 5.73 km, assumed for chondrite and iron projectiles. Besides, CSFD measurements represent an absolute age of about 82 ± 4 Ma based on the 121 isochron fits to the differential data of post-impact craters that suggests recent resurfacing consistent with melt flow during the terminal stages of impact dynamics. © 2025 COSPAR
Machine learning approach for detection of land subsidence induced by underground coal fire using multi-sensor satellite data
(Taylor and Francis Ltd., 2024) Ashwani Raju; Mansi Sinha; Saurabh Singh; Praveen Kumar Kannojiya; Mitali Sinha; Ramesh P. Singh
High-rank coal reserves in Jharia Coalfield (JCF, India), are invariably associated with underground coal fires and land subsidence. This study explores multi-sensor time series satellite data (Landsat 8 OLI and Sentinel-1) through machine learning (ML) to determine the regional ground deformation accompanying coal fires and their contextual relationship. The results show that the highest degree of subsidence is closely associated with the active mine benches with overburden dumps. The relationship between the coal fire and land subsidence parameters is considered as a binary classification problem, explored by calculating the probability of subsidence with a desirable categorical outcome through different ML models. The accuracy of the models is validated using performance metrics that shows that the Random Forest (RF) metrics predict the probability of deformation locations in response to the volume reduction of the burning coal fire and vertical compression due to Overburden Dump (OBD) near active mine benches. The estimated displacement trends have been used to forecast the Autoregressive Integrated Moving Average (ARIMA) method, estimated using Line-of-Sight (LOS) displacement values vary around the best fit within the 95% confidence limits. The trend shows ∼15–25% increase in subsidence compared to the cumulative subsidence. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Machine learning approach for detection of land subsidence induced by underground coal fire using multi-sensor satellite data
(Taylor and Francis Ltd., 2025) Ashwani Raju; Mansi Sinha; Saurabh Kumar Singh; Praveen Kumar Kannojiya; Mitali Sinha; Ramesh P. Singh
High-rank coal reserves in Jharia Coalfield (JCF, India), are invariably associated with underground coal fires and land subsidence. This study explores multi-sensor time series satellite data (Landsat 8 OLI and Sentinel-1) through machine learning (ML) to determine the regional ground deformation accompanying coal fires and their contextual relationship. The results show that the highest degree of subsidence is closely associated with the active mine benches with overburden dumps. The relationship between the coal fire and land subsidence parameters is considered as a binary classification problem, explored by calculating the probability of subsidence with a desirable categorical outcome through different ML models. The accuracy of the models is validated using performance metrics that shows that the Random Forest (RF) metrics predict the probability of deformation locations in response to the volume reduction of the burning coal fire and vertical compression due to Overburden Dump (OBD) near active mine benches. The estimated displacement trends have been used to forecast the Autoregressive Integrated Moving Average (ARIMA) method, estimated using Line-of-Sight (LOS) displacement values vary around the best fit within the 95% confidence limits. The trend shows ∼15–25% increase in subsidence compared to the cumulative subsidence. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Meteorological, atmospheric and climatic perturbations during major dust storms over Indo-Gangetic Basin
(Elsevier, 2015) Sarvan Kumar; Sanjay Kumar; D.G. Kaskaoutis; Ramesh P. Singh; Rajeev K. Singh; Amit K. Mishra; Manoj K. Srivastava; Abhay K. Singh
During the pre-monsoon season (April-June), the Indo-Gangetic Basin (IGB) suffers from frequent and intense dust storms originated from the arid and desert regions of southwest Asia (Iran, Afghanistan), Arabia and Thar desert blanketing IGB and Himalayan foothills. The present study examines the columnar and vertical aerosol characteristics and estimates the shortwave (0.25-4.0μm) aerosol radiative forcing (ARF) and atmospheric heating rates over Kanpur, central IGB, during three intense dust-storm events in the pre-monsoon season of 2010. MODIS images, meteorological and AERONET observations clearly show that all the dust storms either originated from the Thar desert or transported over, under favorable meteorological conditions (low pressure and strong surface winds) affecting nearly the whole IGB and modifying the aerosol loading and characteristics (Ångström exponent, single scattering albedo, size distribution and refractive index). CALIPSO observations reveal the presence of high-altitude (up to 3-5km) dust plumes that strongly modify the vertical aerosol profile and are transported over Himalayan foothills with serious climate implications (atmospheric warming, enhanced melting of glaciers). Shortwave ARF calculations over Kanpur using SBDART model show large negative forcing values at the surface (-93.27, -101.60 and -66.71Wm-2) during the intense dusty days, associated with planetary (top of atmosphere) cooling (-18.16, -40.95, -29.58Wm-2) and significant atmospheric heating (75.11, 60.65, 37.13Wm-2), which is translated to average heating rates of 1.57, 1.41 and 0.78Kday-1, respectively in the lower atmosphere (below ~3.5km). The ARF estimates are in satisfactory agreement with the AERONET ARF retrievals over Kanpur. © 2015 Elsevier B.V.
Predicting Change in Groundwater Storage Associated to Hydroclimatic Variability in the Indo-Gangetic Plains, India
(Institute of Electrical and Electronics Engineers Inc., 2024) Ashwani Raju; Ramesh P. Singh; Mitali Sinha
Despite numerous studies on dwindling groundwater resources in northern India, the linkage between Groundwater Storage (GWS) and hydroclimatic variability in the Indo-Gangetic Plain (IGP) has not been widely studied. In this regard, an attempt has been made to assimilate the satellite-based observations of hydroclimatic variables (predictors) (Precipitation- P, Evapotranspiration- ET, Soil Moisture-SM, and Runoff- RO) to predict GWS using multi-regression machine learning models (Random Forest; R2=0.81). Predicted estimates of the GWS show that northern and NW parts of the IGP are highly affected, and large residual estimates in the eastern parts are due to the uncertainty in the observed P and ET. Despite the performance of the models, spatial biases have been recognized between the observed and predicted estimates of the GWS, suggesting no significant variations among the predictors (hydroclimatic variables) in the major parts of the study area. © 2024 IEEE.
Wave-Tilt Characteristics of EM Waves over a Two Layered Earth Model
(1984) Ramesh P. Singh; Tarkeshwar Lal; B.U.S. Kumar
Wave-tilt amplitudes and phase angle variation in the extended frequency range of 104-107 Hz have been presented for a two layer earth surface model. The effect of conductivity and dielectric constant variation of two layers on wave-tilt amplitude and phase angle have been computed. It is shown to vary with changing thickness of the upper layer. The potentiality of such curves in wave-tilt measurement of the subsurface layer has been discussed. © 1984, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.
Wavetilt Characteristics of EM Waves Over a Homogeneous Earth Model
(1980) Ramesh P. Singh; Tarkeshwar Lal
A theoretical analysis has been carried out to investigate the effect of resistivity, dielectric constant and angle of incidence on the amplitude and phase of the wavetilt over a homogeneous earth model over a range of frequency from very low frequency (VLF) to broadcast band (BCB). Numerical results for a wide range of above mentioned parameters are presented. Dependence of wavetilt on these factors has been discussed. Copyright © 1980 by The Institute of Electrical ind Electronics Engineers, Inc.