Soumik Saha - Academia.edu (original) (raw)

Papers by Soumik Saha

Geosystems and Geoenvironment

Resources, Conservation & Recycling Advances

Applied Water Science, 2022

Scarcity of groundwater is a severe problem in this region due to over exploitation of groundwate... more Scarcity of groundwater is a severe problem in this region due to over exploitation of groundwater from unconfined hard rock aquifers. The main objectives of this study are to analyse the spatiotemporal variability and fluctuation of groundwater table and to predict the location of groundwater depression pockets. Total 21 consecutive years (1996–2017) groundwater monitoring well data (pre- and post-monsoon) have been collected from CGWB, Government of India. The nonparametric Mann–Kendall trend analysis and standardized precipitation index (SPI) have been applied to detect the trend of groundwater level and rainfall variability, respectively. Exponential smoothing has also been fitted for future prediction. The pre- and post-monsoon results (1996–2017) showed that around 77% (22 stations) and 78% (23) monitoring stations were indicating declining trend of groundwater table at the rate of −0.006 to −0.205 m/year and −0.005 to −0.192 m/year, respectively. Similarly, future (2040) grou...

Journal of King Saud University - Computer and Information Sciences, 2021

Stochastic Environmental Research and Risk Assessment, 2021

Worldwide spread out of COVID-19 in a short-time has brought a significant decline of road traffi... more Worldwide spread out of COVID-19 in a short-time has brought a significant decline of road traffic, tourist flow and industrial ventures. During this emergency period, the restricted human dealings with nature have appeared as blessing for health of the total environment. The variation of atmospheric O 3 may modulate the range of UV index (UVI) at any region of the earth. The objective of the study is to examine the variation of UV index over the megacities of India with respect to tropospheric O 3 level modification during COVID-19 lockdown. The meteorological or environmental data (temperature in°C , gust in km/h, wind speed km/h, relative humidity in %, air pressure in mb and cloud cover in okta) of four selective megacities of India (Kolkata, Chennai, Delhi, Mumbai) during and pre lockdown period have been obtained to comprehend about the variation of UV index and tropospheric O 3. The descriptive statistical applications i.e. standard deviation, standard errors and K-means clustering have been done through standard statistical software. In the present study, t-test has been used to understand level of significance of surface O 3 and UVI during pre-lockdown (2019) and lockdown (2020) phase. The result shows that the four major megacities in India namely New Delhi, Mumbai, Kolkata and Chennai have experienced the vibrant diminution in terms of the concentration of UV index with slightly increasing the tropospheric O 3 level during the lockdown phase. The higher accumulation of O 3 during the lockdown in the lower atmosphere of four megacities does not exceed the permissible limit. The excess amount of O 3 has remarkably contributed to trap the harmful UV radiation which has lowered the UVI in these worst polluted megacities of India. In the meantime, the prominent reduction of NO x during the lockdown period decreases the titration impact to O 3 and this mechanism helps to revitalize the ozone concentration level. The uniqueness of the current study is highlighted the ground reality regarding reduction of UV index and amplification of tropospheric O 3 concentration during lockdown phase. This study definitely assists to make new environmental policy, act and law for recover the health of the total environment.

Remote Sensing Applications: Society and Environment, 2021

Abstract The forest cover or broadly forest health is gradually deteriorated day by day due to un... more Abstract The forest cover or broadly forest health is gradually deteriorated day by day due to unexpected population growth, agricultural expansion and infrastructural development mainly in tropical and sub-tropical regions of the world. The Forest fragmentation rate as well as number of vulnerable forest hotspots is significantly intensified within Himalayan terai belt specifically in different pockets of Apalchand forest (India). This paper attempts to identify the vulnerable forest hotspots, fragmentation zone and forest canopy density. The relevant methods such as FCD model, spatial autocorrelation (Moran’s I) and clustering (Getis-Ord Gi∗statistics), forest fragmentation transformation matrix have been used to analyze the spatiotemporal changing patterns of forest fragmentation and canopy health of Apalchand forest. The result shows that the Z-score value is high in the year 1988 and comparatively low in the year 2020, so it has been observed that the forest condition in 2020 is more fragile in comparison with the year 1988. Meanwhile, the Getis-Ord Gi∗ statistics along with IDW method clearly illustrate the clustering of hot-spot and cold-spot regions with high level of significance (90%, 95% and 99%). Similarly, the areas of Patch and Perforated class have been considerably increased with respect to the years1988 and 2000. The hot spot zones are being enlarged in the south-eastern and middle parts of the Apalchand forest. The anthropogenic factors like expansion of tea gardens and agricultural land, infrastructural development, illegal timber trafficking are responsible for rapid fragmentation (Patch, Edge, Perforated areas) as well as reduction of canopy cover in different pockets of the study area. The alternative forest policy is highly required for the conservation of forest ecosystem as well as forest dwellers and forest fringe people.

Environmental Challenges, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Trees, Forests and People, 2020

Environment or natural capitals provide multiple ecosystem services (ESs) and benefits to people.... more Environment or natural capitals provide multiple ecosystem services (ESs) and benefits to people. The approach of ecosystem service values (ESVs) describes the market values of the ecosystem products or services. The changes of ecosystem service valuation and carbon stocks significantly dropped in Ayodhya hill range (extended part of Chhota Nagpur plateau of India) due to rapid land use modification. The principal objectives of this research are (i) to determine the spatiotemporal changing pattern of ESVs through different unit values (for the year 1975, 2000 and 2021) (ii) to analyze the carbon sequestration through InVEST carbon model and (iii) to assess gross primary product (GPP) using MOD17 model. The ESVs result shows that total ESVs over Ayodhya hill range are 256.67, 258.60 and 239.78 million USD for 1975, 2000 and 2021 respectively. Total 16.90 million USD loss has been observed over the study area during the overall study period. Cropland has the highest ESVs due to its hi...

Scientific Reports, 2021

The global economic activities were completely stopped during COVID-19 lockdown and continuous lo... more The global economic activities were completely stopped during COVID-19 lockdown and continuous lockdown partially brought some positive effects for the health of the total environment. The multiple industries, cities, towns and rural people are completely depending on large tropical river Damodar (India) but in the last few decades the quality of the river water is being significantly deteriorated. The present study attempts to investigate the river water quality (RWQ) particularly for pre- lockdown, lockdown and unlock period. We considered 20 variables per sample of RWQ data and it was analyzed using novel Modified Water Quality Index (MWQI), Trophic State Index (TSI), Heavy Metal Index (HMI) and Potential Ecological Risk Index (RI). Principal component analysis (PCA) and Pearson’s correlation (r) analysis are applied to determine the influencing variables and relationship among the river pollutants. The results show that during lockdown 54.54% samples were brought significantly p...

Environmental Challenges, 2021

Abstract Drought is a hydrological extreme and it brings negative consequences over environment, ... more Abstract Drought is a hydrological extreme and it brings negative consequences over environment, society and livelihood. Globally, drought frequency and magnitude is being amplified due to natural as well as anthropogenic causes. This scientific research attempts to examine the drought severity, trend and consequences applying the SPI and SPEI indices in the extended part of Chhota Nagpur Plateau (India) considering last 25 years period along with 3, 6, 9, and 12 months time scale. Mann-Kendall test and future prediction have also been done to find out the trend of drought. The results show that the frequency and trend of meteorological and ground water drought are being amplified and the years 1999, 2003, 2010, 2015 and 2016 have been recorded as extreme drought. The research revealed that the principal causes of drought are slight change of precipitation, unscientific withdrawal of ground water, modification of cropping patterns and drastic landuse change. District statistical bureau report states that drought events eventually reduce the crop production in most of the blocks of Purulia and severe water crisis creates during post monsoonal months in this particular region. The future prediction result signifies that around 60% mild and 6% severe drought will be faced using SPI index while around 64% mild and 5% severe drought will be occurred considering SPEI index. This scientific study along with integrated watershed management strategies will definitely assist to the regional planners and administrators for sustainable water resource management particularly for semi-arid climatic region of India.

Geoscience Frontiers, 2021

The higher concentration of PM10 and PM2.5 in the lower atmosphere is severely harmful for human ... more The higher concentration of PM10 and PM2.5 in the lower atmosphere is severely harmful for human health and it also makes visibility diminution along with weather and climate modifications. The main objective is to find out the spatiotemporal variation and dispersal of PM10 and PM2.5 along with COVID-19 infection in the dusty city Kolkata. The consecutive two years PM10 and PM2.5 data of different stations have been obtained from State Pollution Control Board, Govt. of West Bengal. Forward trajectory analysis has been done through HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model to find the path and direction of air particles. The result showed that the various meteorological or environmental factors (such as temperature, relative humidity, wind, wind speed, pressure and gusty wind) and geographical location regulate the spatiotemporal variation of PM10 and PM2.5. These factors like high temperature with relative humidity and strong wind influence to disperse the particulate matters from north to south direction from city to outside during summer in Kolkata metropolitan city. During summer (both pre and lockdown years), the height of particles is extended up to 1000 m owing to active atmospheric ventilation whereas in winter it is confined within 100 m. The HYSPLIT model clearly specified that the particles dispersed from south, south-west to north and north east direction due to strong wind. The constant magnification of PM10 and PM2.5 in the lower atmosphere leads to greater frequency of COVID-19 infections and deaths. In Kolkata, the one of the crucial reasons of high infection and deaths (COVID-19) is co-morbidity of people.

Environmental Challenges, 2021

Kolkata is the third densely populated city of India and Kolkata stands in the World's 25 mos... more Kolkata is the third densely populated city of India and Kolkata stands in the World's 25 most polluted cities along with 10 worse polluted cities in India. The relevant study claims that due to the imposition of lockdown during COVID-19 pandemic, the atmospheric pollution level has been significantly reduced over the metropolitan city Kolkata like other cities of the world. The main objective of this study is to predict the concentration of PM2.5 using multiple linear regression (MLR) and artificial neural network (ANN) models and similarly, to compare the accuracy level of two models. The concentration of PM2.5 data has been obtained from state pollution control board, Govt. of West Bengal and daily meteorological data have been collected from the world weather website. The results show that non-linear artificial neural network model is more rational compared with multiple linear regression model due to its high precision and accuracy level (in respect to RMSE, MAE and R2). In this research artificial neural network (ANN) model exhibited higher accuracy during the training and testing phases (root mean square error (RMSE), mean absolute error (MAE) and R2 indicate 3.74, 1.14 and 0.91 respectively in training phase and 2.55, 4.32 and 0.69 in testing phase respectively). This model (ANN)) can be applied to predict the concentration of PM2.5 during the execution of urban air quality management plan.

From the last month of 2020, sudden outbreak of novel corona virus caused socio-economic lockdown... more From the last month of 2020, sudden outbreak of novel corona virus caused socio-economic lockdown in many countries. Many studies proved that temporary shutdown of economic sectors helped to recover river water quality. Perhaps, for the first time, this present study is conducted in an industrially and agriculturally influenced catchment of river Damodar, India. This research was fixed some relevant objectives like (i) to evaluate the changes of heavy metals (Zn, Cd, Pb, Ni, Cr and Fe) and microbial contamination (TVC, TC and FC) of river water (ii) to identify the magnitude of human health hazard during lockdown compared to pre lockdown and unlock phase. Total 33 water samples were collected in three periods. During lockdown, TVC, TC and FC showed the gradual decreasing trend in this stretch. All samples exceed the concentration of microbes compared to recommended standard in three periods. Among all heavy metals, Zinc, iron, chromium found their abandoned presence in the river wat...

Environment, Development and Sustainability, 2020

The fatal novel coronavirus (COVID-19) pandemic disease smashes the normal tempo of global socioe... more The fatal novel coronavirus (COVID-19) pandemic disease smashes the normal tempo of global socioeconomic and cultural livelihood. Most of the countries impose a lockdown system with social distancing measures to arrest the rapid transmission of this virus into the human body. The objective of this study is to examine the status of air quality during and pre-COVID-19 lockdown and to recommend some long-term sustainable environmental management plan. The pollution data like PM 10 , PM 2.5 , O 3 , SO 2 , NO 2 and CO have been obtained from State Pollution Control Board under Govt. of West Bengal. Similarly, various land surface temperature (LST) maps have been prepared using LANDSAT-8 OLI and LANDSAT-7 ETM + images of USGS. The maps of NO 2 and aerosol concentration over Indian subcontinent have been taken from ESA and NASA. The digital thematic maps and diagrams have been depicted by Grapher 13 and Arc GIS 10.3 platforms. The result shows that the pollutants like CO, NO 2 and SO 2 are significantly decreased, while the average level of O 3 has been slightly increased in 2020 during the lockdown due to close-down of all industrial and transport activities. Meanwhile, around 17.5% was the mean reduction of PM 10 and PM 2.5 during lockdown compared with previous years owing to complete stop of vehicles movement, burning of biomass and dust particles from the construction works. This study recommends some air pollution-tolerant plant species (in urban vacant spaces and roof tops) for long-term cohabitation among environment, society and development.

Journal of Evolution of Medical and Dental Sciences, 2016

Goiter means enlargement of thyroid gland. Endemic goitre due to iodine deficiency is a health pr... more Goiter means enlargement of thyroid gland. Endemic goitre due to iodine deficiency is a health problem that afflicts with varying degrees of severity, an estimated 40 million people throughout the Indian subcontinent. [1] The progressive nature of this disease occasionally results in severe tracheal compression and acute airway distress. Apart from goiters that are suspicious of cancer or possible cancer or inconclusive, surgery may be also recommended for those with benign biopsy results if the nodule is large, if it continues to increase in size or if it is causing symptoms (Pain, difficulty swallowing, etc.). Here, we report a case of large goitre with discussion on the difficulty faced during surgery, complications and how they were managed.

Journal of Case Reports, 2015

Geosystems and Geoenvironment

Resources, Conservation & Recycling Advances

Applied Water Science, 2022

Journal of King Saud University - Computer and Information Sciences, 2021

Stochastic Environmental Research and Risk Assessment, 2021

Remote Sensing Applications: Society and Environment, 2021

Environmental Challenges, 2021

Trees, Forests and People, 2020

Scientific Reports, 2021

Environmental Challenges, 2021

Geoscience Frontiers, 2021

Environmental Challenges, 2021

Environment, Development and Sustainability, 2020

Journal of Evolution of Medical and Dental Sciences, 2016

Journal of Case Reports, 2015