Ramkrishna Maiti

Vidyasagar University · Department of Geography and Environment Management

Slope instability is a serious concern in the Sikkim Himalayas. The town and numerous road segments along National Highway 31A were ravaged by multiple landslides that occurred in the nearby region. A bivariate statistical method known as frequency ratio (FR), information value (IV), and certainty factor (CF) analysis was employed in this work to e...

Land use directly controls the river water pollution of a region throughout the year, as all the pollutants from the basin come through sewages (point source). The toxicity of heavy metals (HMs) causes health hazards to the people of the Damodar River basin. Arsenic, lead, copper, cadmium, chromium, nickel, mercury and zinc are tested from the coll...

Unlabelled: The COVID-19 (SARS-CoV-2) pandemic is wreaking havoc on the planet, yet control of waste materials comforted the ecosystem during the lockdown restricting human activities. Damodar is the most important tributary of the lower Ganga River in West Bengal. It flows through an industrially developed, agriculturally flourished populated are...

Floods are catastrophic natural disasters that inundate large areas and cause loss of life and property, property, and crops. The nature and extent of floods are much higher in the lowland plains than in the plateau region through the accumulation and inundation of a higher volume of water from the upland. The flood susceptibility model is essentia...

The analysis of land use and land cover change has become necessary and urgent in the field of man–environment relation or resultant global environmental change. The present study analysed temporal and spatial changes of land use and land cover (LULC) in Purulia district covering an area of 6300 km2 by comparing classified LANDSAT satellite images...

The Eastern Himalayas is ecologically fragile and at the same time is also home to some of the world’s poorest people. Thus, to assess the nature and extent of resource utilization by the locals and its implications on the geomorphology, the present work attempts to present the prevailing scenario of anthropogenic alteration of the fluvial environm...

Addresses the various aspects of applied geomorphology and contemporary issues Covers approaches and methods applicable in present-day geomorphological, geographical and environmental studies Highlights issues caused by climate changes, geomorphic hazards and human impact

The Morphotectonic characteristics of Chel river was examined through the analysis of Shuttle Radar Topography Mission (SRTM) DEM-based geomorphic indices to investigate the effects of neotectonics on channel characteristics and landform development. The individual and cumulative analysis of geomorphic indices such as Relief Ratio (Rh), Drainage ba...

Landslide is one the catastrophic event in Himalayan region. The settlement and roads are immensely affected by the landslide which is not only observed in east Sikkim Himalaya but also the entire mountain regions. The NH 31A road of East Sikkim Himalaya experiences numerous landslide events. The present objective of this study to embed various lan...

The lower course of the Damodar River in West Bengal is one of the most polluted stretches in the Ganga River basin. There is a lack of research along the whole course of the Damodar, and parameter level analysis receives little attention. Eleven monitoring sites were chosen based on the potential sources of pollution for 6 years (2014–2019). Multi...

The study aims to estimate annual sediment yields of Mayurakshi River Basin using SWAT tool of ArcGIS. Climatic aspects, soil, land use and slope maps were integrated within SWAT tool to predict sediment yield capacity using MUSLE method. Alongside, the study attempts to identify spatial distribution of major gully erosion prone sites using ANN and...

The study assessed the role of mangrove to the livelihood of people living in world’s largest mangrove forest. Analysis has also been done on the livelihood assets and major stresses over the livelihood. A survey was conducted over 254 households (HHs) from 22 villages located at the fringe areas of Indian Sundarbans. The result shows that more tha...

The Sikkim Himalaya has been recognized as region enormously susceptible slope instability. The NH 31A road falls with east Sikkim Himalaya which has highly deformed by numerous landslide events. Over the few years the NH 31A road sections and settlement with its surrounding areas are invaded by landslide events. To resolve the problem connected to...

The Sikkim Himalaya has been identified as a zone with a high risk of slope instability. The NH 31A route runs through the east Sikkim Himalaya, which has been severely affected by landslides. Over the last few years, landslide occurrences have engulfed the NH 31A road portions and town, as well as the adjacent countryside. Landslide susceptibility...

Human interventions have largely influenced morphological, ecological and aesthetic quality of many rivers across the world. Scientists and researchers have developed several indices to measure ecological quality, ecological health and pollution status using physical, biological and chemical parameters. But the physical biological and chemical stat...

The Sundarbans, a UNESCO world heritage site, is of immense importance for its ecological and economic utilities. This paper attempts to identify, assess and classify the degree of vulnerability along the 269 km coastal stretches of Indian Sundarbans using GIS-based composite index. This study implies five physical and one social variable (geomorph...

Soil erosion is one of the major environmental hazards causing severe land degradation in the sub-tropical monsoon dominated Mayurakshi river basin (MRB) of Eastern India. Hence, this study aims to delineate the areas with severe soil erosion probability (SEP) using logistic regression (LR), decision tree (DT), and Random forest (RF). A soil erosio...

The people of Sundarbans are well experienced with multiple hazards affected their life and livelihood since the incitation of 1st civilization over here. Low lying delta plain and massive population pressure increases the exposure limit of this area. For saving this valuable ecosystem and millions of people living here coastal planners and decisio...

The Mayurakshi river is one of the most important rivers in the Geographical Scenario of the Eastern India. The river is subject to several morphological alterations due to complex interaction with the natural eco-geomorphological set up and human interferences. Therefore, the present study aims to understand the morphological sensitivity of the Ma...

Agricultural productivity is the synthetic reection of agricultural efciency in which different inputs are being used and it helps to recognize the regional inequalities in agriculture. The main focus of the present study is on the district wise variation of trends in agricultural productivity in West Bengal from 1991 to 2011 as well as its relat...

The Lower Damodar Region comprises some blocks of Barddhaman, Hugli and Haora district of West Bengal. This region suffers from recurrent floods. This study attempts to characterize this flood as an alluvial fan flooding. The guidance of the committee of Alluvial Fan Flooding (National Research Council, USA) has been applied to characterize Damodar...

Deficiency in rainfall introduces drought phenomena with temporal and spatial variability in terms of intensity and magnitude. Study of drought in different scales is necessary for successful planning in a country such as India, where agricultural sector contributes highest in economy. Drought indices (DI) have a tool to quantify the drought nature...

In spite of whole hearted efforts from India and Bangladesh to solve the problem of sharing Ganga water through bi-lateral treaties (1975, 1977, 1982, 1985 and 1996), none of these could yield optimum result as per expectations. The present work aimed to identify the cause of such failure and it is understood that shortage of water availability at...

We have studied bank erosion and accretion along the Putharjhora-Kranti reaches of the Chel River, piedmont Sikkim Himalaya using SOI topographical maps of 1955 and 1970, and Landsat images of 1976, 1987, 1994, 2005, 2010 and 2017. Extensive field survey was also conducted to supplement the study and thereby verify the findings derived from GIS ana...

Fan delta is formed when an alluvial fan prograde directly into the standing body of water from the adjacent highland. An ancient fan delta was developed 6–10m above from the present sea level at the lower course of Damodar river in the western part of Bengal basin. The present study attempted to represent the evolutionary history of Damodar fan de...

Sundarbans, world’s largest mangrove forest is now struggling to maintain its existence in the face of severe erosion. Any management process to protect this vulnerable ecosystem and to rescue millions of people living here, require place specific erosion measurement. This paper attempted to assess point specific erosion/accretion rate between 1975...

Morphometric analysis of Chel basin was carried out with the help of geographic information system (GIS). Mosaic of two Shuttle Radar Thematic Mapper (SRTM) 1Arc V3 (30m) tiles was used to prepare Digital Elevation Model (DEM). The watershed boundary was delineated and drainage lines were identified using Arc Hydro tools in ArcGIS 10.1 by collabora...

Textural analysis of surface sediments is very useful tool to understand the complex interaction between terrestrial and marine environment. Total 180 sediment samples (60 samples in each season) have been collected from the lower reach of the Rupnarayan River and sieving technique is used to calculate different size parameters. Approximately, 63.8...

The lower reach of the Rupnarayan River, from Kolaghat to Geonkhali (40 km) has been showing signs of rapid deterioration and incapacitation due to sedimentation that creates a series of inter-connected problems. Asymmetry of the cross-sections leads to channel dynamism due to concentration of energy near the bank. Channel widening and separation o...

Being a part of Hoogly estuary, the lower reach of the Rupnarayan River is affected by semi-diurnal tide of Bay of Bengal. Tidal range, tidal prism, tidal asymmetry and variation of tidal velocity in different phases play dominant role to control the mechanism and rate of sedimentation in the lower reach. Tidal gauge data have been collected at an...

Channel forms and patterns are important determinants of ease of movement of water and sediment and immediate clearance of materials from up slope. Twenty five (25) cross-sections have been drawn along the lower reach of the Rupnarayan River, by measuring river depth using Echo Sounder and collecting stuff readings using leveling instrument, to und...

Seasonal variation of stream hydraulics was monitored to understand and explain the mechanism of sedimentation. Water velocity is measured by floating method and using digital current meter. Density of water is measured by testing the collected water samples in the laboratory. The pattern and nature of flow is identified by Reynolds Number and Frou...

Amount of suspended sediment in water is measured by collecting water samples from different depths during high and low tide. Rate of transportation of bed load has been computed using well accepted empirical equations. Suspended sediment amount ranges between 3.1 and 5.05 gm/l in non-monsoon season and 4.97 and 6.5 gm/l in monsoon season. During n...

In the lower reach of the Rupnarayan River, sedimentation is the result of the combined interaction between fluvial and marine processes. Seasonal variation of available shear stress during high and low tide in connection to critical shear stress is the main factor controlling sedimentation. Sediments are mostly transported by suspension with rolli...

X-ray diffraction (XRD) technique is used to understand the sources of sediments through identification of mineral composition of sediments in the lower reach of the Rupnarayan River to explain the causes and mechanisms of sedimentation. A total of 21 sediment samples (13 samples from river bed and 8 samples from river banks) have been collected fo...

Causes and mechanisms of sedimentation are explained in connection to the seasonal fluctuation of shear stress. Available and Critical shear stress have been calculated following DuBoys and Shield formula. Critical shear stress of sediment entrainment varies from 0.031 to 0.147 N/m² in pre-monsoon, 0.041 to 0.169 N/m² in monsoon and 0.034 to 0.148...

Grain size of sediments relates to the physical characteristics of the depositional environments. The distribution of sediment grain size is affected by the variations of wave energy and turbulent conditions of depositing environment. Linear Discriminate Analysis (LDA) technique and bi-variate plotting of grain size parameters are used to explain a...

This book elucidates sedimentation processes at work in the Rupnarayan River, with particular focus on the environment of sediment deposition under a tidal system. It addresses the various complexities arising from the interactions between riverine and marine processes, as well as the seasonal fluctuations in available and critical shear stress tha...

The study aimed to assess the heavy metals (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Pb, Sr, Zr) contamination in the soil of mine affected Singaran river basin and to analyse spatial variation in the contamination level considering 32 soil samples. Elemental analysis of soil samples has been performed through Energy Dispersive X-ray Analysis (EDX) t...

The lower reach of the Rupnarayan River has been deteriorated and incapacitated due to continuous sedimentation (26.57 million m³ shoaling in last 25 years). Attempts have been made to explain the causes and mechanisms of sedimentation in connection to the seasonal fluctuation of shear stress. River depth and water velocity was measured by echo-sou...

During the last 20 years the lower reach of the Rupnarayan River has experienced a net shoaling of 26.57 million m(3) (survey made by Kolkata Port Trust, 1992-2012) with 42.04 million m(3) shoaling and 15.47 million m(3) scouring. Bathymetric close grid survey of the study area was made using Leveling instrument and Echo sounder interfaced with Pos...

Sources of sediments have been identified through study of mineral composition of sediments in the lower reach of the Rupnarayan River, West Bengal, India by X-ray diffraction (XRD) technique to understand the causes and mechanisms of sedimentation. Collected sediment samples are washed by hot and distilled water, dried and disaggregated manually w...

Soil organic carbon (SOC) and organic carbon density (OCD) is an active indicator of soil fertility and productivity, and it fluctuates spatially and temporally. The main objective of the present study is to evaluate the spatial variability of SOC and OCD using geostatistics model as well as field methods at Sagar Island (Sundarban), India. Soil sa...

Soil organic carbon (SOC) and organic carbon density (OCD) is an active indicator of soil fertility and productivity, and it fluctuates spatially and temporally. The main objective of the present study is to evaluate the spatial variability of SOC and OCD using geostatistics model as well as field methods at Sagar Island (Sundarban), India. Soil sa...

Accurate assessment of the spatial variability of soil properties is key component of the agriculture ecosystem and environment modeling. The main objective of the present study is to measure the soil properties and their spatial variability. A combination of conventional analytical methods and geostatistical methods were used to analyze the data f...

Present study presented a methodology for landslide susceptibility mapping using an integrated geospatial technology and ground based observation. IRS LISS-III satellite data, drainage, slope, aspect, geology, geomorphology and land use were integrated into GIS platform to delineate landslide susceptibility zone based on weighted index overlay meth...

The ecological, economical, and agricultural benefits of accurate interpolation of spatial distribution patterns of soil organic carbon (SOC) are well recognized. In the present study, different interpolation techniques in a geographical information system (GIS) environment are analyzed and compared for estimating the spatial variation of SOC at th...

The present study was conducted to assess soil organic carbon (SOC) and other nutrients under different land use patterns in the lateritic region at Medinipur Block of Paschim Medinipur District, West Bengal, India. Samples were collected from different land use categories in 17 locations at soil depths of 0–19, 20–39, and 40–100 cm. The physical a...

The present paper is based on field investigation and measurement of rill erosion processes at Rangamati Experimental Station (Medinipur, West Bengal in India). In rill experiments, three different natural rills were studies in field for understanding of the dynamics of soil erosion processes of a rill catchment area. Geometric and morphological ch...

The present paper demonstrated an image processing technique of surface soil crack analysis. The geometric features of cracks, such as width, length, and surface area are estimated. These parameters are important, because they influence both the soil hydraulics and mechanics. The crack intensity factor was introduced as a descriptor of the extent o...

The dynamic nature of a landscape results from the interaction of surface run-off with rocks and soil being guided by geo-hydrologic variables. The estimation of surface run-off and its better understanding reveals a clear idea about the degree and amount of surface erosion and slope vulnerability over the space. In this chapter Soil Conservation S...

The present study deals with the assessment of geo-technical parameters i.e. surface inclination (⊝), soil depth (z), cohesion (c), angle of internal friction (φ), soil saturation index (m), soil density (γs) and density of water (γw) and to construct 1D (one dimensional) Slope stability model for preparing the slope instability map under dry, semi...

To prepare landslide susceptibility map of the Shivkhola watershed, one of the landslide prone part of Darjiling Himalaya, RS and GIS tools were being used to integrate 10 landslide triggering parameters like lithology, slope angle, slope aspect, slope curvature, drainage density, lineament, upslope contributing area (UCA), road contributing area (...

The present study established the link between critical rainfall (cr), critical slope angle (cs), critical height (ch) and landslide. The critical rainfall was estimated incorporating geo-technical parameters such as angle of internal friction (\(\varphi\)), slope angle (⊖), upslope contributing area (UCA), transmissivity (T), wet soil density (ps)...

Soil erosion is an imperative environmental deterioration that leads to serious impact on physical, economical and ecological in developing countries. Present study investigates farmers' views of soil erosion problems and their conservation knowledge and practices in the Kangsaboti watershed (South Bengal, India) to understand the complex interrela...

The gully erosion is the most serious environmental problem in West Bengal in India. Present study focused on delineation the gully affected areas and characterization of geo-environmental factor in the gully affected region to prevent future problems. Ground investigation and geo-spatial data along with bivariate statistical approach were employed...

Surface excavation and overburden dumping in the Raniganj Coalfield have defaced the natural topography and impacted the hydrology. Excavation and dumping of overburden within the channels has obstructed streamflow and altered water availability in the lower parts of small catchment basins. The surface drainage paths of ephemeral channels and flow...

In the present authors attempted to have a clear insight into the interworking of geotectonic, geomorphic, hydrologic and anthropogenic factors leading to landslide in the Shiv khola Watershed, the most worst affected region of Darjiling Himalaya. This book includes the parameters responsible for landslide events in mountainous areas. It provides k...

The fundamental impetus of any kind of natural hazard and risk management is an awareness of threat, a notion of responsibility and a brief that human action might reduce the risk. Various components such as susceptibility analysis, hazard and risk identification, consequence analysis, hazard analysis, and risk evaluation are included in the landsl...

The stability of mountain slope depends upon physical and chemical properties of the soil. In the present work geomorphic properties such as slope angle, slope aspect, slope curvature, lithological composition, and lineament as well as behaviour of slope materials such as texture, cohesion (c), friction angle (\(\varphi\)), water holding capacity,...

Quantitative geomorphology provides a systematic approach to the analysis of a complex landscape of any size. The stability of the mountain slope depends upon the prevalence of various hydrologic variables. In the present work, the excess and deficit moisture period in a year and its role in slope instability were assessed studying rainfall and eva...

Field investigations on gully morphology and its inherent processes have been conducted in lateritic region in the western margin of Bengal Basin. At Here-Parvat, rilling and swelling processes produced deeply cracked surface drained by a finely textured network of shallow rills. At Rangamati, rilling and piping are differentially developed on slop...

Field investigations on gully morphology and its inherent processes have been conducted in lateritic region in the western margin of Bengal Basin. At Here-Parvat, rilling and swelling processes produced deeply cracked surface drained by a finely textured network of shallow rills. At Rangamati, rilling and piping are differentially developed on slop...

In the present study, attempts are made to understand the interaction of processes operating in a dynamic estuarine system assess the causes that concentrate stress on embankment leading to frequent breaching. Due to exclusion of intertidal area, tidal creeks are incapacitated; these are narrowed down and are completely closed by human intervention...

With the advent of mining activities at Raniganj coalfield in India, the natural topography has been defaced in some elongated tracts by either excavation or dumping. This paper deals with opencast mining induced defaced topography of Raniganj coalfield, which needs to be reclaimed properly right after mining. This paper investigated intensity of d...

Gully erosion management on lateritic soil is a critical issue in West Bengal. In this paper, have been used in combination with vegetation and check dams, for all aspects of lateritic soil erosion management. A program for controlling gully erosion was carried out in Rangamati in lateritic soil region of western part of West Bengal from 2011 to 20...

The lateritic badland topography (Western part of West Bengal, India) is prone to severe erosion, caused by heavy rainfall events of short duration and high intensities. Five catchments were instrumented in order to study the rainfall– runoff process and soil management impact on runoff and/or sediment yield. In the five micro catchments (Rangamati...

The lithological composition and lineaments plays a significant role in landslide activities over mountain slope. In the present study of the Shivkhola Watershed, Darjeeling Himalaya, the existence of lineaments in seven lithological groups and their varying response to atmospheric processes have made the concerned study area more vulnerable to lan...

Bathymetric close grid survey of the lower reach of Rupnarayan River was made using Dumpy Level and Echo sounder interfaced with Position Fixing System (GPS). Simultaneous tidal observations were available at an interval of half-an hour. Velocity during high and low tide is measured by Digital water current meter and floating method. Rate of sedime...

Field investigations on gully morphology and its inherent processes have been conducted in lateritic region in the western margin of Bengal Basin. At Here-Parvat, rilling and swelling processes produced deeply cracked surface drained by a finely textured network of shallow rills. At Rangamati, rilling and piping are differentially developed on slop...

To prepare a landslide susceptibility map of Shiv-khola watershed, one of the landslide prone parts of Darjeel-ing Himalaya, remote sensing and GIS tools were used to integrate 10 landslide triggering parameters: lithology, slope angle, slope aspect, slope curvature, drainage density, upslope contributing area (UCA), lineament, settlement density,...

Landslip events are triggered by the rainfall which causes a great damage to human lives and properties worldwide. The present study, encompasses the relationship between rainfall and landslide, the determination of the critical rain and its return period and the assessment of temporal probability of rainfall that triggers landslip events. Landslid...