Monitoring of Snow Cover Variability in Chenab Basin Using IRS AWiFS Sensor     

B. P. Rathore  S. K. Singh  Purnesh Jani  I. M. Bahuguna  Rupal Brahmbhatt  A. S. Rajawat  S. S. Randhawa  Anjana Vyas 《Journal of the Indian Society of Remote Sensing》2018,46(9):1497-1506

Monitoring of seasonal snow cover is important for many applications such as melt runoff estimation, climate change studies and strategic requirements. Contribution of seasonal snow melt runoff of Chenab River is significant and important to meet hydrological requirement at foothills. Seasonal snow cover of Chandra, Bhaga, Miyar, Bhut, Warwan and Ravi, six major tributaries of Chenab River, becomes crucial to assess the water availability. In addition, altitudinal distribution of snow cover significantly influences the melt runoff which is highly sensitive to minor variations in atmospheric temperature. In this investigation, remote sensing based Normalized Difference Snow Index technique has been used to generate 10 daily snow cover product. Snow cover monitoring of all the sub-basins were carried out for 10 years from 2004–2005 to 2013–2014 during hydrological year (October to June) using Advanced Wide Field Sensor (AWiFS) of Indian remote sensing satellite (IRS). Accumulation and ablation patterns of snow cover have also been analyzed for the six sub-basins. Accumulation and ablation pattern of snow cover, from 2004 to 2014 which shows slightly increasing trend for all the sub-basins. Meteorological data of Kelong at Bhaga sub-basin was also analysed. Average monthly snow line altitude was estimated for all the sub-basins using hypsographic curve. Chandra and Bhaga sub-basins are at higher altitude and Ravi sub-basin is at lower altitude. It was also observed that areal extent of snow reaches to lower altitude during last 5 years, particularly in Ravi sub-basin.  相似文献   

A restudy of the Ostracoda <Emphasis Type="Italic">Cypris cylindrica</Emphasis> Sowerby (in Malcolmson, 1840) from the Deccan Intertrappean beds (late cretaceous) of Lakshmipur,Kachchh, Gujarat     

S. C. Khosla  M. L. Nagori  S. R. Jakhar  A. S. Rathore  Manisha Kumari 《Journal of the Geological Society of India》2009,74(5):579-584

Cypris cylindrica was originally described by Sowerby (in Malcolmson, 1840) from the Deccan Intertrappean sedimentary beds of the Sichel Hills, Andhra Pradesh. Whatley and Bajpai (2000) recorded the species during recent years from the Intertrappean of Lakshmipur, Kachchh district, Gujarat and stated that Kachchh specimens are identical with the types of the species housed in the Natural History Museum (NHM), London. They recorded the species as Mongolianella cylindrica. The species, however, lacks distinctive shape and hinge structure of Mongolianella and on the contrary closely resembles Stenocypris cylindrica major (Baird, 1859) in shape and internal characters including having adont hinge, large anterior vestibulum, arcuate lists or striae on free part of inner lamella, numerous short marginal pore canals and 6 large adductor scars, the topmost being much elongated. On these bases the species is herein transferred to the genus Stenocypris Sars, 1889.  相似文献   

Makran ophiolitic basalts (SE Iran) record Late Cretaceous Neotethys plume-ridge interaction     

Rasoul Esmaeili  Mohammad Ebrahimi  Ji’En Zhang  Zhiyong Zhang  Yasser Abd El-Rahman 《International Geology Review》2020,62(13-14):1677-1697

ABSTRACT

The Makran complex in southeast Iran provides a spectacular subduction-related accretionary complex to understand the mechanism of oceanic accretion and the evolution of subduction zones. In this paper, we present new major and trace element data as well as isotopic compositions of mafic volcanic blocks from the Makran ophiolitic mélange complex (OMC). Our aim is to assess the genesis of these rocks and discuss their implications on the evolution of Neotethys Ocean. These volcanic blocks are composed mainly of basalts with minor trachytes. The Makran lavas are occasionally interlayered with tuff layers. Zircons from these tuffs give U-Pb ages of 95 Ma, which is well in accordance with the reposted microfossil data for the interlayered pelagic limestones with pillow lavas. Makran basalts can be geochemically subdivided into four groups; normal to transitional MORB, enriched-MORB, Plume-type MORB and alkaline (-OIB-like) basalts. The OIB-like pillow lavas are represented by high values of Th/Tb (6.3–7.4) which are higher than other basalts (group 1 = 0.3–0.8; groups 2 = 0.7–1.6; group 3 = 1.58–1.36).¹⁴³Nd/¹⁴⁴Nd_(t) ratios for basalts ranges from 0.51247 to 0.51292, whereas ⁸⁷Sr/⁸⁶Sr_(t) isotopic composition of the OMC lavas varies from 0.704433 to 0.709466. The Pb isotopic composition of the lavas are quite high, ranging from 15.49–15.66 for ²⁰⁷Pb/²⁰⁴Pb_(t), 18.09–19.12 for ²⁰⁶Pb/²⁰⁴Pb_(t) and 37.80–39.23 for ²⁰⁸Pb/²⁰⁴Pb_(t). The chemistry of these rocks suggests that they were formed most likely in an oceanic setting with clear plume-ridge interaction. These rocks can form from partial melting of a highly heterogeneous mantle source, which is extensively metasomatized with deep mantle OIB-type components. We suggest these rocks have been generated in an oceanic ridge with plume-ridge interaction, similar to the Iceland-Reykjanes Ridge, before being fragmented and accreted into the Makran accretionary complex.  相似文献   

Utilization of Lime for Stabilizing Soft Clay Soil of High Organic Content     

Mohamed A. Sakr  Mohamed A. Shahin  Yasser M. Metwally 《Geotechnical and Geological Engineering》2009,27(1):105-113

This paper presents the results of geotechnical and mineralogical investigations on lime-treated soft clay soil from Idku City, Egypt, where high organic matters of about 14% exist. Lime was added in the order of 1%, 3%, 5% and 7% by weight and laboratory experiments after 7, 15, 30 and 60 days were conducted including the mineralogical and microstructural examinations, grain size analysis, plasticity limits, unconfined compressive tests, vane shear tests and oedometer tests. The results indicate that soft clay soil of high organic content of 14% can be stabilized satisfactorily with the addition of 7% lime. The results also demonstrate that the changes in the mineralogical contents and soil fabric of high organic lime-treated soft clay improve soil plasticity, strength and compressibility.  相似文献   

Ecological benefits of urban forestry: The case of Kerwa Forest Area (KFA), Bhopal,India     

Puneet Dwivedi  Chinmaya S. Rathore  Yogesh Dubey 《Applied geography (Sevenoaks, England)》2009,29(2):194-200

In developing countries like India, migration of people from rural to urban areas is responsible for ever expanding urban boundaries. This trend is exerting significant pressure on unprotected natural forests located near urban centers. This paper highlights the case of Kerwa Forest Area (KFA), located at about 10 km from the city of Bhopal, capital of Madhya Pradesh state. The objectives of this study are to quantify the extent of disturbance faced and ecosystem services provided by the KFA. Suitable spatial technologies and forest sampling techniques have been used to achieve the objectives of the study. It was found that the KFA is currently facing severe anthropogenic pressure. Parts of the KFA, located close to the settlements, were found more disturbed than the parts which were located far from the settlements. In spite of disturbances, KFA is a habitat for many threatened and endangered plant, animal, and bird species. KFA also plays a critical role of a carbon sink with a total storage of about 19.5 thousand tons of aboveground carbon. Immediate precautionary measures are required to prevent further degradation of the KFA for ensuring better environmental quality for the residents of Bhopal city in the future.  相似文献   

Some magnetic fabric characteristics of sheared zones   总被引：1，自引：0，他引：1  

Jaswant S. Rathore   《Journal of Geodynamics》1985,2(2-3)

In this paper the magnetic susceptibility anistropyy technique has been evaluated for the purpose of identifying shear zones in deformed regions and for detecting movements on shear planes. The magnitude parameters and orientations of the susceptibility ellipsoid show distinct characteristic behaviour on traversing deformed zones. The actual shear lines are characterized by the very high values of anistrropy and anisttropy gradients in their vicinities. The orientational data give clear indication of any relative rotations across questionalbe boundaries. Furthermore, a semi-analytical method is outlined for determining detailed pice-meal movements along shear lines as well as giving the regional movement direction. It is not possible to quantify the movements since too many parameters are unknown.  相似文献   

Effects of seawater irrigation on soil microbial community structure and physiological function     

Doongar R. Chaudhary  Aditya P. Rathore  Bhavanath Jha 《International Journal of Environmental Science and Technology》2016,13(9):2199-2208

Irrigation with diluted seawater would be an alternative water resource which can play an important role under scarce resources of freshwater for promoting agricultural production in coastal areas. Salvadora persica Linn. was irrigated with different concentrations of seawater (0, 10, 20, 40, 60, 80 and 100 % seawater), and their effect on plant growth, nutrient contents in soil and plants, shift in soil microbial community structure (phospholipid fatty acid; PLFA) and community-level physiological profiling (CLPP, Biolog ECO MicroPlate) were studied. Plant dry matter was significantly increased with all seawater treatments, and highest increase was at 20 % seawater treatment. Sodium and chloride contents were significantly increased, whereas ratios of K/Na and Ca/Na were significantly decreased in plants with seawater irrigation. Soil electrical conductivity (EC), available K and Na were significantly increased with increasing the concentration of seawater. Total PLFA concentration and PLFA profile of soils were used as indices of total microbial biomass and community composition, respectively. The concentrations of total PLFA, gram-positive, gram-negative and actinomycetes biomarker PLFAs were significantly reduced at 20, 40, 80 and 40 % concentrations of seawater, respectively. The application of different concentrations of seawater induced a clear shift in the soil microbial community structure toward the bacterial abundance. The microbial community structure and community-level physiological profiling in seawater irrigation treatments had significantly differentiated. It can be concluded that irrigation with different concentrations of seawater had significant impact on soil chemical and microbial properties which is attributed due to the salinity stress.  相似文献   

Chemostratigraphy of the Cenomanian-Turonian shallow-water carbonate: new correlation for the rudist levels from north Sinai,Egypt     

Yasser F Salama  Gouda I Abdel-Gawad  Shaban G Saber  Soheir H El-Shazly  G. Michael Grammer  Sacit Özer 《Arabian Journal of Geosciences》2016,9(20):755

The present study aims to provide carbon-isotope curves for the Cenomanian to Turonian rudist-dominated successions in north Sinai. The high-resolution carbon-isotope curves obtained from north Sinai sections provide new insight for calibrating the age of rudists as well as for evaluating the effects of the oceanic anoxic event 2 (OAE2) on rudist communities. The primary goals are (1) to provide a high-resolution sequence stratigraphic framework for the Cenomanian-Turonian succession, (2) to use rudist and ammonite biostratigraphic data to distinguish the stratigraphic levels of the rudist species, and (3) to integrate the chemostratigraphic (δ¹³C) profile and the rudist levels to improve the biostratigraphy based on the rudist distributions and the carbon-isotope data. The recognition of three ammonite zones through the Cenomanian-Turonian succession was utilized to identify four temporally significant rudist levels indicative of the Lower Cenomanian, Middle Cenomanian, Upper Cenomanian, and Middle Turonian, respectively. Most of the rudists occur in the highstand deposits of medium-scale sequences. Carbon- and oxygen-isotopic analyses were carried out on both rudists and surrounding carbonate units. Based on the variations in the carbon-isotope signals, 12 chronostratigraphic segments were identified in the studied sections. The Cenomanian carbon-isotope segments (C23–C30) were obtained from the Halal Formation at Gabal Yelleg and Gabal Maaza sections, while the Turonian segments (C30–C34) were measured from the Wata Formation at Gabal Yelleg section. The carbon-isotope record from the studied sections is consistent with the trends documented in previous studies of the Tethyan realm. The Cenomanian-Turonian boundary is placed at the onset of falling carbon-isotope values (δ¹³C) from 2.61 to ?0.25‰ in the upper part of OAE2 with the carbon-isotope segment C30 at Gabal Yelleg. The negative shift in δ¹³C values (C33) occurred in the Middle Turonian lowstand deposits characterizing the global sea level fall during this interval.  相似文献   

Moraine-Dammed Lakes study in the chenab and The Satluj River Basins using IRS data     

S. S. Randhawa  R. K. Sood  B. P. Rathore  A. V. Kulkarni 《Journal of the Indian Society of Remote Sensing》2005,33(2):285-290

Moraine-dammed lakes are normally formed near glacier terminus. These lakes can burst due to excessive melting and can cause floods in the valleys. Many such floods have been reported in the Himalayas and other parts of the World. In this paper, an inventory of these lakes in the Satluj and the Chenab basins has been reported. During the investigation, 22 lakes in the Satluj and 31 lakes in the Chenab basin were mapped. In the Chenab basin, two lakes are of very large size, their areal extent is 105 and 55 ha, located in toposheet number 52 HI 1 and 52H02, respectively. These lakes were selected for detail monitoring. The lake near the Geepang glacier, is located in toposheet number 52H 02 and its area was 27 ha in 1976. Using the satellite data, areal extent of the lake was monitored. The lake area was almost doubled to 55 ha in 2001. This suggested that, lake size is constantly increasing and it can cause outburst flood. The maximum possible depth of lake was estimated by taking the average difference of maximum and minimum height of moraine dam from the Survey of India toposheet. By considering the average depth, the volume of the lake water and the instantaneous discharge of 350 mVsec were estimated. This is large discharge for a small stream like the Geepang Gath and it can damage many civilian and defense establishments. Therefore, further detail field investigations of this lake are needed to assess threat potential and to develop strategy to avoid this flash flood.  相似文献   

Recession of samudra tapu glacier, chandra river basin, Himachal Pradesh     

Anil V. Kulkarni  Sunil Dhar  B. P. Rathore  Babu Govindha Raj K.  Rajeev Kalia 《Journal of the Indian Society of Remote Sensing》2006,34(1):39-46

Himalayas possess one of the largest resources of snow, ice and glaciers that act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health of the Himalayas. Samudra Tapu is one of the largest glaciers in Chandra basin of district Lahaul and Spiti, Himachal Pradesh. Based on the field investigations and the remote sensing techniques. features such as accumulation area, ablation area snowline/equilibrium line, moraine-dammed lakes and permanent snowfields were mapped. The glacial terminus was identified using moraine-dammed lake, as lake is located at down streamside of the terminus. The total recession of glacier during the period of 38 years (1962–2000) is about 742 m with an average rate of 19.5 m/yr. In addition, glacial extent is reduced from 73 to 65 km² between 1962 and 2000. suggesting overall deglaciation of 11%. During field investigation. three stages of glaciation using terminal moraine were identified. These moraines were mapped by merging LISS-II1 and PAN data. At the peak of glaciation. the glacial terminus was extended 3.18 km downstream of terminus position in year 2000. Total area during peak of glaciation period has been observed to be 77.67 km², which is 12.67 km² higher than the present glacier extent.  相似文献