Maini P.,Ministry of Earth science |
Rathore L.S.,Mausam Bhavan
Current Science | Year: 2011
A pilot study was conducted to assess the economic impact of weather forecast-based advisories issued to 15 of the 127 Agrometeorological Advisory Service (AAS) units of the Ministry of Earth Sciences, Government of India. Six seasons comprising three Kharif (summer) and three Rabi (winter) during 2003-2007 were chosen. The major crops chosen for the study included food grains, oilseeds, cash crops, fruit and vegetable crops. The sample set consisted of 80 farmers, comprising 40 responding and 40 non-responding farmers. The main aim was to study the percentage increase/ decrease in the yield and net return due to AAS. Results obtained suggest that the AAS farmers accrued a net benefit of 10-15% in the overall yield and a reduction by 2-5% in the cost of cultivation over the non-AAS farmers.
Jain S.K.,Indian Institute of Technology Roorkee |
Kumar V.,Ministry of Earth science |
Kumar V.,National Institute of Hydrology |
Saharia M.,National Institute of Technology Silchar
International Journal of Climatology | Year: 2013
The northeast region (NER) of India covers an area of 0.26 million km2. This region is one of the highest rainfall-receiving regions on the planet. Consequently, it has huge water and hydropower potential and analysis of rainfall and temperature trends would be of interest to water and energy planners. Trends in monthly, seasonal, and annual rainfall and temperature on the subdivision and regional scale for the NER were examined in this study. Trend analysis of rainfall data series for 1871-2008 did not show any clear trend for the region as a whole, although there are seasonal trends for some seasons and for some hydro-meteorological subdivisions. Similar analysis for temperature data showed that all the four temperature variables (maximum, minimum, and mean temperatures and temperature range) had rising trend. Notably for the post-monsoon season, the Sen's estimator of slope (°C/year) was 0.019, 0.011, and 0.015 for the maximum, minimum, and mean temperature, respectively. © 2012 Royal Meteorological Society.
Rawat G.,Wadia Institute of Himalayan Geology |
Arora B.R.,Ministry of Earth science |
Gupta P.K.,Indian Institute of Technology Roorkee
Tectonophysics | Year: 2014
Magnetotelluric (MT) measurements along a profile cutting across the Garhwal Himalaya of India are inverted to obtain 2-D electrical resistivity structures of the Himalayan wedge and of the underthrusting Indian plate. The imaged resistivity cross-section is dominated by a low-angle north-east dipping intra-crustal high conducting layer (IC-HCL) with an average thickness of 5. km. At transition from the Lesser Himalaya to the Higher Himalaya, the IC-HCL is marked by a ramp structure across which its top jumps from a depth of 8. km to 13. km. High conductivity of the layer is caused by pounding of upward propagating metamorphic fluids trapped by tectonically induced neutral buoyancy. In compression regime of the Himalaya, the mechanical weakening effects of the fluids counteract the fault-normal stresses, thereby facilitating thrust-type earthquakes on a plane imaged as the top of the IC-HCL. It is suggested that in the Himalaya collision belt, like the active subduction zone, the active seismic plane forming seat of large and great earthquakes is located a few kilometers above the top of the down-going plate. In this tectonic setting, the high conductance ramp symbolizes a block of low shear strength and high strain, which under the deviatoric stresses release accentuated stresses into the brittle crust, thereby generating small but more frequent earthquakes in the narrow Himalayan Seismic Belt. In response to either the co-seismic pumping or the stress transfer during inter-seismic period, the upward infiltration of fluid fluxes into the over pressurized zones sufficiently reduces the shear strength of local thrusts and shear zones, turning these into locales of concentrated seismicity. © 2014 Elsevier B.V.
Pandey A.,Ministry of Earth science
International Journal of Mining Science and Technology | Year: 2013
Polymetallic sulphides have been consistent source of metals like iron, copper, zinc and lead. Apart from these they are also seen as economically viable resources of silver and gold. As the demand of these metals is showing an astoundingly increasing trend, the search for their resources has also increased in similar folds. This has resulted in many nations' focus on deep seabed resources of the polymetallic sulphides. Consequently, International Seabed Authority (ISBA) has provided 'Regulations' to obtain plan of work for exploration of polymetallic sulphide deposits in deep seabed 'Area'. Following the release of these Regulations, several countries are in the process of obtaining the licence for exploration of these metals from the deep seabed regions. Detailed information about the science and ISBA Regulations for exploration of polymetallic sulphide deposits is prerequisite to submit an application to ISBA for their exploration. The current contribution provides a comprehensive review of the science behind locating polymetallic sulphide deposits in geological setting of deep seabed as well as about the ISBA Regulations for their exploration. © 2013 Published by Elsevier B.V. on behalf of China University of Mining & Technology.
Shah S.K.,University of Lucknow |
Bhattacharyya A.,University of Lucknow |
Chaudhary V.,Ministry of Earth science
Dendrochronologia | Year: 2014
The relationship of streamflow records of the Lachen River with tree-ring parameters of total tree-ring width (TRW), earlywood width (EWW) and latewood width (LWW) chronologies of Larix griffithiana from Lachen, North Sikkim, Eastern Himalaya was generated. These chronologies correlate significantly with the observed discharge of the Lachen River where the EWW chronology explains 61.2% of the streamflow variance. Based on this result, Lachen River discharge for the period of previous year March to current year February was reconstructed using EWW chronology, which extends back to AD 1790. In the smoothed reconstructed data the period of extreme low streamflows were during AD 1791-1805, 1813-1822 and 1914-1925 and the extreme highs were during AD 1823-1835, 1879-1890, 1926-1946 and 1980-1989. The streamflow is also found to be lower than average during the monsoon failure (or East India Drought) of AD 1792-1796 and past great droughts of AD 1876-1878. The lower tree growth during AD 1816-1822 is consistent with that of the Tambora volcanic eruption of Indonesia in AD 1815. High spectral power at 4-8 years in the reconstructed streamflow is similar to that of ENSO range. © 2012 Elsevier GmbH.