Tapas Ranjan Martha
@nrsc.gov.in
Scientist
National Remote Sensing Centre
RESEARCH, TEACHING, or OTHER INTERESTS
Geology, Earth-Surface Processes, Geotechnical Engineering and Engineering Geology, Space and Planetary Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Imlirenla Jamir, Vipin Kumar, Arun Kumar Ojha, Vikram Gupta, Tapas Ranjan Martha, and D. V. Griffiths
Springer Science and Business Media LLC
Sudhanshu Dixit, Srikrishnan Siva Subramanian, Piyush Srivastava, Ali P. Yunus, Tapas Ranjan Martha, and Sumit Sen
Copernicus GmbH
Abstract. Debris flows triggered by rainfall are catastrophic geohazards that occur compounded during extreme events. Few early warning systems for shallow landslides and debris flows at the territorial scale use thresholds of rainfall intensity–duration (ID). ID thresholds are mostly defined using hourly rainfall. Due to instrumental and operational challenges, current early warning systems have difficulty forecasting sub-daily time series of weather for landslides in the Himalayas. Here, we present a framework that employs a spatio-temporal numerical model preceded by the Weather Research And Forecast (WRF) Model for analysing debris flows induced by rainfall. The WRF model runs at 1.8 km × 1.8 km resolution to produce hourly rainfall. The hourly rainfall is then used as an input boundary condition in the spatio-temporal numerical model for debris flows. The debris flow model is an updated version of Van Asch et al. (2014) in which sensitivity to volumetric water content, moisture-content-dependent hydraulic conductivity, and seepage routines are introduced within the governing equations. The spatio-temporal numerical model of debris flows is first calibrated for the mass movements in the Kedarnath catchment that occurred during the 2013 North India floods. Various precipitation intensities based on the glossary of the India Meteorological Department (IMD) are set, and parametric numerical simulations are run identifying ID thresholds of debris flows. Our findings suggest that the WRF model combined with the debris flow numerical model shall be used to establish ID thresholds in territorial landslide early warning systems (Te-LEWSs).
Nirmala Jain, Priyom Roy, Punit Jalan, Tapas R. Martha, and Iswar C. Das
Elsevier BV
Nirmala Jain, Priyom Roy, Tapas R. Martha, Nataraja P. Sekhar, and K. Vinod Kumar
Springer Science and Business Media LLC
Swati Singh, Prakash Chauhan, Priyom Roy, Tapas R. Martha, and Iswar C. Das
Springer Science and Business Media LLC
Priyom Roy, Tapas R. Martha, K. Vinod Kumar, and Prakash Chauhan
Springer Science and Business Media LLC
Swati Singh, Nikhil K. Baranval, Tapas R. Martha, and I.C. Das
European Association of Geoscientists & Engineers
Priyom Roy, Tapas R. Martha, K. Vinod Kumar, Prakash Chauhan, and Vala Venkateshwar Rao
Springer Science and Business Media LLC
Vipin Kumar Maurya, Ramji Dwivedi, and Tapas Ranjan Martha
Elsevier BV
Lina Hao, Cees van Westen, A. Rajaneesh, K.S. Sajinkumar, Tapas Ranjan Martha, and Pankaj Jaiswal
Elsevier BV
Suresh Devaraj, Kiran Yarrakula, Tapas Ranjan Martha, Geetha Priya Murugesan, Divya Sekhar Vaka, Samvedya Surampudi, Abhinav Wadhwa, Parthiban Loganathan, and Venkatesh Budamala
Springer Science and Business Media LLC
Priyom Roy, Ivaturi N. Rao, Tapas Ranjan Martha, and K. Vinod Kumar
Elsevier BV
Priyom Roy, Tapas R. Martha, Kirti Khanna, Nirmala Jain, and K. Vinod Kumar
Elsevier BV
Ramesh Pudi, Santosh Joshi, Tapas R. Martha, Rajeev Upadhyay, and Charu C. Pant
Informa UK Limited
ABSTRACT We attempted a comprehensive site response study of Garhwal-Kumaun Himalaya in the Central seismic Gap (CSG) using the data collected from 97 strong motion, microtremor and broadband stations. Site response parameters such as predominant frequency (fpeak ), site amplification (Amax) and average shear-wave velocity up to a depth of 30 m (VS30) were estimated by adopting the Nakamura technique. Spatial maps of these parameters were prepared to show the distribution of site response functions across the region. The estimated parameters show a good correlation with site geology. Decreasing order of sediment thickness from foothills to Lesser Himalaya was observed in the region. The estimated VS30 values were correlated with global VS30 values as well as available field measurements and 1D velocity inversion results, it shows a good agreement. The sites were classified as per the NEHRP site classification scheme based on the VS30 value. From this study, we inferred that the VS30 values estimated from the Nakamura technique can be used as an alternate proxy for determining the average shear wave velocity up to a depth of 30 m in the absence of substantial field measurements due to challenging terrain conditions. Such results of site response analysis may be used for preliminary earthquake hazard assessment in the region.
Nirmala Jain, Tapas R. Martha, Kirti Khanna, Priyom Roy, and K. Vinod Kumar
Springer Science and Business Media LLC
Ramesh Pudi, Tapas R. Martha, Priyom Roy, K. Vinod Kumar, and P. Rama Rao
Springer Science and Business Media LLC
Tapas Ranjan Martha, Priyom Roy, Nirmala Jain, K. Vinod Kumar, P. Sashivardhan Reddy, J. Nalini, S. V. S. P. Sharma, Abhinav Kumar Shukla, K. H. V. Durga Rao, B. Narender,et al.
Springer Science and Business Media LLC
Kirti Khanna, Tapas R. Martha, Priyom Roy, and K. Vinod Kumar
Springer Science and Business Media LLC
Tapas Ranjan Martha, Priyom Roy, Nirmala Jain, Kirti Khanna, K. Mrinalni, K. Vinod Kumar, and P. V. N. Rao
Springer Science and Business Media LLC
Kirti Khanna, Tapas R. Martha, Priyom Roy, and K. Vinod Kumar
Springer Science and Business Media LLC
Alessandro Cesare Mondini, Fausto Guzzetti, Kang-Tsung Chang, Oriol Monserrat, Tapas Ranjan Martha, and Andrea Manconi
Elsevier BV
Ramesh Pudi, Priyom Roy, Tapas R. Martha, and K. Vinod Kumar
Wiley
ABSTRACTThe Garhwal–Kumaun region of the Himalaya encompassing the state of Uttarakhand, India, has experienced several earthquakes in the past. Damage due to earthquakes is controlled by local site conditions, primarily resonance frequency and wave amplification from the ground. We present local site parameters with their site geology for 37 sites using ambient noise data. Horizontal to vertical spectral ratio technique is used to estimate the spectral ratio curves. Based on the type of curve, sites are classified into four classes, viz. clear peak, broad peak, double and multi‐peak, and flat H/V curve. Sites seen with clear or broad peaks are located on either soil or weathered rocks, thus indicating large impedance contrast and sharp discontinuity with large velocity contrast. Multiple peaks are observed in either soil or boulder bed and reveal large impedance contrast, probably representing shallow and thick strata. Sites with flat curves are found on weathered/phyllite/granite gneiss/granite schist rock types within highly dissected hilly areas. Fourteen sites have a peak frequency >6 Hz with a dominance of broad and clear peaks in the Lesser and Higher Himalayan regions. On the contrary, foothills and part of Siwalik sites exhibited a peak frequency between 1.14 and 4.94 Hz. The results demonstrate that sites with thick soil cover and boulder bed areas, that is, Doon valley and foothills, show low‐frequency peaks and hard rock or shallow bedrock sites, that is, Lesser and Higher Himalaya exhibit a higher frequency range. The estimated H/V amplitude and peak frequency values have shown a good correlation with site geology and geomorphology.