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An International Year of Planet Earth-2008 Initiative

Current Issue Technical

Year 2019

Volume 12 (2)

ESI.12.2.2019.6
Micromorphological Study of Kashmir Loess-Paleosol Sediments: A Tool for Stratigraphic and Paleoclimatic Reconstruction
Ishtiaq Ahmad1 and Rakesh Chandra2
Abstract

 

Integrated lithological, micromorphological and SEM studies of the Quaternary loess-paleosol sediments of the Kashmir Valley were carried out in order to reconstruct paleoclimatic history of the Kashmir valley during Middle to Late Pleistocene period. The pedological observations revealed that these paleosols are weak to moderately developed representing cold arid to warm semi-arid climatic conditions. Various pedological features also indicate that numbers of loess-paleosols events in the sequences reflect subtle climatic changes that affect relative rates of material supply and weathering rates and these paleosol profiles are formed when both loess deposition and pedogenic processes were taking place simultaneously during either phase of the loess/soil formation cycle. However, balance between the rate of sedimentation and rate of pedogenesis changed in cyclic fashion. Four periods of relatively higher precipitation and temperature conditions occurred in the Kashmir Valley. These periods are observed in paleosol profiles DS2, DS3, DS5 and DS7 of Dilpur Village section and their stratigraphic equivalent at Karapur and Burzahom Village sections. These periods of relatively higher precipitation and temperature conditions do not each represent complete interglacial period. The paleosols DS3, KS4 and BS4 are relatively well developed and record maximum thickness, which may represent one full interglacial period. The loess horizon DL1 and paleosolsDS1, KS1 and BS1 probably represent the last glacial maximum (LGM) in Kashmir valley and the Last Glacial was interrupted by arid and warm semi-arid intervals when BS3 and BS2 paleosol profiles and their stratigraphic equivalent are formed. Also the lower part of the sections below the DL2 and KL1 is interpreted as the fluctuation probably within the last interglacial period. Overall the climate of the valley for most of the times fluctuated between cold arid to warm semi-arid during the recent past.

 

Keywords: Loess-Paleosols; Kashmir; Dilpur; Micromorphology, SEM

ESI.12.2.2019.7
Some Climatological Aspects of Convective Systems at Five Major Cities of West Bengal, India
N. UmaKanth1, G. Ch. Satyanarayana1, Baby Simon2 and M. C. Rao3
Abstract

Disasters related to convective systems are considered to be global phenomena, as they may occur anywhere in the world, at any instant. Thunderstorms, hailstorms, lightning, dust storms are some of the disasters associated with these convective systems. Some of these systems may possess great potentiality to produce serious damages to human life and property. Indian region is vulnerable to severe convective systems during the hot period of pre-monsoon season. In this paper, the climatological aspects of the convective systems over five major cities of West Bengal region namely Kolkata, Darjeeling, Asansol, Silliguri and Durgapur has been attempted using LIS TRMM satellite data (1995-2014), ERA-Interim ECMWF satellite data (1979-2010) and GPCC precipitation dataset (1901-2010). Thermodynamic atmospheric stability indices such as K Index (KI), Total Totals Index (TTI), Humidity Index (HI) and Total Precipitable Water (TPW) associated with severe convection system over study region were studied to provide guidance to severe convective activity. Convective available potential energy (CAPE) and Rainfall also helped us to study the convective systems seasonally and decadally. All the major cities in West Bengal on an average are receiving high lightning flashes which is a major disaster leading to human loss and high property and crop damage. The threshold values of the indices we have taken for the study are satisfied with values mentioned in the literature. Results of this study may help disaster management to take risk reduction steps.

 

Keywords: Rainfall, Convective available potential energy (CAPE), K Index (KI), Total Totals Index (TTI), Humidity Index (HI) & Total Precipitable Water (TPW).
ESI.12.2.2019.8
Assessment of Sea Level and Morphological Changes along Indian Coastal Areas during 1975-2005
Sridhara Nayakand Manabottam Mandal
Abstract

Recent studies showed evidences of coastal accretion in many regions because of natural erosion and anthropogenic activities. On the contrary, sea level is rising in almost every coast across the World and leading to inundation. Present study estimated the changes in sea level and land areas along Indian coast during 1975-2005 using onscreen visual interpretation of Landsat images (60m resolution) for 1975 and 2005, and a newly developed sloping method at 615 coastal points from Shuttle Radar Topography Mission (SRTM) images (90m resolution) and the Permanent Service for Mean Sea Level (PSMSL) dataset. The results records sea level rise in the tune of 1.415 mm per year during 1975-2005 along Indian coast and the average slant height of inundated area is 2.136m during this period. The overall results (considering accretion and inundation) indicate an effective land area increase by ~103.4 sq. km along Indian coast during 1975-2005. However, these estimates can be improved further by providing more reliable slopes and appropriate boundary points using higher resolution images along the coastline.

 

Keywords: Changes in coastal land area; Sea level rise; On-screen visual interpretation; Remote sensing

ESI.12.2.2019.9
Groundwater Quality Assessment for Drinking Purpose Based on Water Quality Index in Gabharu River Basin, North-East, India
Bandeepa Medhi1, Madhurjyojit Chakravartty2 and BidyutBikash Sharma3
Abstract

The present study was conducted to evaluate the groundwater quality and its suitability for drinking purpose, in the Gabharu river basin, North-East India, with reference to water quality index. Water quality index, indicating the water quality in terms of index number, offers a useful representation ofoverall quality of water for public use as well as water quality management. Groundwater samples from 23 selected locations were taken for investigation and analysed for chemical parameters including pH, Electrical conductivity, Hardness, Total Dissolved Solid, Sodium, Potassium, Calcium, Magnesium, Bicarbonate, Chloride, Sulphate, Fluoride and Iron with regard to drinking water standards and assessed for their suitability for human consumption. The analysis resulted that the northern part of the lower catchment area is contaminated, thereby experiencing water quality which is not suitable for drinking purposes. Whereas, towards the southern part of the study area, the groundwater is of good quality.

 

Keywords- Water Quality Index, Drinking Water, Gabharu River, North-East India