Browsing by Author "Mallikarjun Mishra"

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Confirmation of Nature of Palaeo-course of Assi River, India: Some Significant Revelations from Electrical Resistivity Tomography
(Geological Society of India, 2024) Mallikarjun Mishra; Sanjay Rana; Praveen Kumar Rai; Prafull Singh; K. N. Prudhvi Raju
A long and continuous palaeo-course of Assi River, in between Prayagraj and Varanasi, in the Ganga River plains with indications of good groundwater potential had been traced from remote sensing data. Electrical Resistivity Tomography (ERT) has been conducted along eight lines for confirmation of the same palaeo-course in general and to specifically ascertain the nature of the course—the past flow conditions and the type of deposits. The variation in the thickness of channel deposits along the concave and convex banks and the middle parts is an indication of lean flow. The mixed fractions of channel deposits are an indication of dumping of sediments in the dying stages of a river. The ERT investigation has further helped in delineating the high resistive palaeo-channels (20 to 50 Ohm.m), the low resistivity aquiclude clay layer (<15 Ohm.m) and the deeper and relatively higher resistivity sandy layer (>50 Ohm.m), which could be the principal aquifer in the area. © 2024 Geological Society of India, Bengaluru, India.
Flood Reduction and Prevention Possibilities in the Flood Plains: A Study of the Varuna River Basin in the Flood Plain of the Ganga River, Uttar Pradesh, India
(Geological Society of India, 2024) Mallikarjun Mishra; V.A.V. Raman; K. N. Prudhvi Raju
Floods are a recurring phenomenon in the floodplain region of the Ganga River largely caused by several floodplain tributaries. One such tributary of the Ganga in its floodplain is the 225 km long monsoon-fed Varuna River. Using high-resolution Google earth satellite images, 662 tals (local word for large natural ponds), and 15383 other smaller ponds/ tanks (natural and man-made), were identified and delineated. The tals and ponds/tanks occupy 430 km2 and 93 km2 respectively, within the 3141 km2 area of the Varuna River basin. Based on the areas and approximate water depths that were averaged from field measurements at selected tals and ponds/tanks, the total water-holding capacity of all these water bodies is estimated to be as much as 57% (1140 million cubic metres) of the total surface water runoff of the basin. In spite of such a large water-holding capacity within these tals and ponds/ tanks, floods are still an almost annual phenomenon in the Varuna basin because (i) water is not allowed to accumulate in the tals and (ii)the ponds/tanks have shrunk and/or silted up, reducing their volume. Deepening by desilting of tals and ponds/tanks can be taken up by engaging the local labourers through the government-funded rural employment guarantee schemes. The majority of the village tals and ponds/tanks can be used for pisciculture in order to generate development funds. © 2024 Geological Society of India, Bengaluru, India.
Groundwater evidences in confirmation of palaeo-course of Assi River in Uttar Pradesh, India
(Indian Academy of Sciences, 2022) Mallikarjun Mishra; K. N. Prudhvi Raju
The palaeo-course of the Assi river in Uttar Pradesh, India was delineated through visual image impressions using remote sensing data. To corroborate on the existence of this palaeo-course 192 open wells and several ponds along and within the palaeo-course were observed showing very shallow groundwater table. Also, eight trenches dug within the channel and over the natural levees confirmed the existence of very shallow groundwater conditions. The observations of wells were made and trenches were dug during January–February 2020, by which time most of the ponds away from the channel dry out and the water column in the wells outside the course is reduced compared to the ponds and wells located over the banks and wells within the palaeocourse and outside it corroborates the existence of the Assi palaeo-course. © 2022, Current Science. All Rights Reserved.
Need for pan-India compatibility of geospatial databases in terms of map projections and parameters
(Taylor and Francis Ltd., 2023) Mallikarjun Mishra; K.N. Prudhvi Raju; Prem Chandra Pandey
The present study is taken up to record variations in the extent of area of two polygons—(i) a ground measured area of a university campus, (ii) enclosing the Ganga basin—and to examine the changes in both shape and area of another (iii) polygon covering India under different map projections with various parameters. The exercise brought forth interesting results. Depending on final ranks worked out based on minimum differences in extent of areas and shape distortion in the case of India, it is suggested to adopt either (i) Lambert Conformal Conical (LCC) projection with Everest India-Nepal datum, First Standard Parallel (FSP) 24.50, Second Standard Parallel (SSP) 28.50, Latitude of Origin (LO) 16.253259, Central Meridian (CM) 80.8749 or (ii) LCC projection with WGS 84 datum, FSP 24.50, SSP 28.50, LO 16.253259, CM 80.8749 or (iii) Polyconic with Everest India-Nepal datum, CM 84.50, LO 13.00, for mapping both smaller areas on larger scales and larger areas on smaller scales. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Palaeo and present channel of Assi river, Uttar Pradesh, India
(Indian Academy of Sciences, 2020) Mallikarjun Mishra; K. N. Prudhvi Raju; P.V. Raju
The Assi river in Varanasi, Uttar Pradesh, India, is now a small, local, ephemeral floodplain tributary of River Ganga, with a length of about 8 km and catchment area of about 22 km2. It has also turned into a filthy drain. There are evidences in the form of palaeochannels, through patterns of water bodies and settlements along them, to suggest the origin of Assi river near Allahabad flowing through a distance of about 120 km up to Varanasi to meet the Ganga. There is also the possibility that Assi started as a takeoff from River Ganga and flowed as a Yazoo stream. Through on-screen digitization from high and medium-resolution remote sensing data-BHUVAN and Google Earth, CORONA aerial photographs, IRS P6 LISS-IV, Landsat 1, 3, 5, 7, 8-and a number of cross profiles from SRTM 30 m digital elevation model (DEM), palaeochannel of Assi has been delineated. Also, a 1 m DEM was generated for the present Assi catchment area from about 5000 DGPS points to present proof that the present Assi is a misfit in once a wider valley shaped by heavy discharge coming from a greater length of channel and a larger catchment area. © 2020, Indian Academy of Sciences.
Precision mapping of boundaries of flood plain river basins using high-resolution satellite imagery: A case study of the Varuna river basin in Uttar Pradesh, India
(Springer, 2019) Mallikarjun Mishra; Vikas Dugesar; K.N. Prudhviraju; Shyam Babu Patel; Kshitij Mohan
Accurate demarcation of river basin boundaries is an important input for any programme connected with watershed management. In the present study, the boundary of the Varuna river basin is automatically derived using coarse- and medium-resolution digital elevation models (DEMs) of SRTM-30 m, ASTER-30 m, Cartosat-30 m, ALOS Palsar-12.5 m and Cartosat-10 m as well as manually through on-screen digitisation from a very high-resolution 1 m × 1 m remote sensing data available as Google Earth image. The study demonstrated the efficacy of on-screen digitisation from high-resolution Google Earth image supported by detailed field observations in the precision mapping of the place of origin of the Varuna River, its stream network and basin boundary when compared to the maps generated through automatic methods using DEMs of various resolutions. The Varuna river system takes its headwaters from the areas surrounding Umran and Dain ‘tals’ (shallow, large depressions/basins) but not from the west of Mau Aima town as has been previously reported. © 2019, Indian Academy of Sciences.
Textural analysis and statistical synthesis to interpret depositional environments in the palaeochannel of the Assi River in the Central Ganga Plain, India
(Springer Nature, 2025) Mallikarjun Mishra; Shyam Kanhaiya; Birendra Pratap Singh; Koppella N. Prudhvi Raju
The current study is aimed to characterize the facies based on grain-size composition and textural parameters along the palaeo-course of the Assi River in Central Ganga Plain, India. Grain size fractions are expressed in terms of ratios of sand, silt and clay and plotted in ternary diagrams, while grain-size variations are used to explain the sediment transport mechanism, depositional history and energy levels during sedimentation. The palaeochannel deposits of the river in study largely consist of silty sandy mud with sand silt clay in various proportions. The occurrence of minor proportions of fine sands and silts in clay suggests successive stream episodes/floods in the recent past. The palaeochannel sediments show mean size ranges from 3.83 to 7.02 phi (average = 5.38 phi), indicating coarse to very fine silt, and sorting ranges from 0.81 to 2.49 phi (average = 1.87 phi), indicating moderately to very poor sorted sediments. Skewness varies from − 0.01 to 0.81(average = 0.28), indicating near-symmetrical to very fine-skewed sediment distributions and kurtosis ranges from 0.85 to 1.89 (average = 1.21) suggest that the majority of the sediments are mesokurtic to very leptokurtic in nature. The bivariate plot of mean grain size versus sorting shows that the bulk of the sediments were deposited in quiet-water environment under episodic fluvial regimes. The C–M pattern of the sediments in the palaeochannel suggests that sediments were transported in graded to uniform suspension before they are deposited. © Indian National Science Academy 2025.
Tracing of palaeochannels of Bakulahi river system in Uttar Pradesh, India
(Springer Verlag, 2019) Shashi Shekhar Shukla; Mallikarjun Mishra
Palaeochannels can be good possible reservoirs of groundwater and are good rechargeable aquifers. Bakulahi is a plain-fed tributary of the Sai River flowing from north-west to south-east direction with about 177-km length and about 841-km2 catchment area. It emanates from interconnected series of tals (large- to medium-sized shallow depressions) situated in the Raebareli district, Uttar Pradesh, India. Course of the Bakulahi River is shifted laterally and left many fluvial landforms—palaeochannels, oxbow lakes, meander cutoff, etc. The present study is based on the on-screen digitization of the Bakulahi River basin boundary, drainage network, palaeocourses, and other surface water bodies from high-resolution remote-sensing data (1 m × 1 m) available at Google Earth. The digitized details from remote sensing data are validated with some field observations. Different thematic maps are prepared by converting Google Earth feature files (.kmz/.kml) into GIS feature files (.shp) and importing layers into the GIS environment. There are about 115 palaeochannels covering about 137-km2 area (16.29%); about 6000 surface water bodies in forms of ponds/tanks having 23.36-km2 area (2.74%) and 40 oxbow lakes are mapped within the basin. This is the first scientific attempt to trace palaeocourses of the Bakulahi River. The present paper also answers the question about the origin of the Bakulahi River. Demarcation of precise basin boundary through manual method by using high-resolution remotesensing data is another contribution of this exercise which is otherwise a difficult task without the availability of high resolution DEM. © 2019, Saudi Society for Geosciences.