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Papers by Ravinder Dhiman

Environmental Science and Pollution Research

COVID-19 has wreaked havoc throughout the planet within a short time frame, inducing substantial ... more COVID-19 has wreaked havoc throughout the planet within a short time frame, inducing substantial morbidity and mortality in the global population. The primary procedures commonly used to manage the pandemic can produce various environmental pollutants, primarily contaminants of emerging concern such as plastics, chemical disinfectants, and pharmaceutical waste. There is a huge influx of various environmental pollutants due to the pandemic effect. We, therefore, introduce the term "envirodemics" depicting the exacerbated surge in the amount of pandemic-induced pollutants. The general toxicity pattern of common chemical ingredients in widely used disinfectants shows negative impacts on the environment. We have identified some of the significant imprints of the pandemic on localizing the Sustainable Development Goals-environment interaction and their implications on achieving the goals in terms of environmental benefits. Climate change impacts are now widespread and have a profound effect on pollutant fluxes and distribution. The climate change signatures will impact the pandemic-induced enhanced fluxes of pollutants in the global waters, such as their transport and transformation. In this study, possible interactions and emerging pathways involving an emerging climate-health-pollutant nexus are discussed. The nexus is further elaborated by considering plastic as an example of an emerging pollutant that is produced in huge quantities as a by-product of COVID management and disaster risk reduction. Additionally, regulatory implications and future perspectives concerning the unleashed nexus are also discussed. We hope that this communication shall call for incisive investigations in the less explored realm concerning the healthpollutant-climate nexus.

Journal of Coastal Conservation

The process of environmental spatial planning in coastal regions involves classification of areas... more The process of environmental spatial planning in coastal regions involves classification of areas into different categories by retaining the synergy between environmental conservation and urban development.  Existing coastal regulations for classification of coastal regions in India are lack scientific rigorousness.

Ocean & Coastal Management

Applied Water Science

Coastal cities contrive to spread their transformative influence both into the hinterland, along ... more Coastal cities contrive to spread their transformative influence both into the hinterland, along the coastline, and into the coastal waters themselves. These effects will be intensified in urban agglomerations as the concentration of population and allied activities are more pronounced there compared to the inland regions. Indian coastal cities are no exception, and it is high time to delineate these hazard-prone regions and implement proper mitigation and adaptation strategies at city scale. This review article provides an assessment regarding quantification, management and climate change impacts of flood risks in Surat, Mumbai, Chennai and Kolkata, which are the most populated coastal cities in India. The flood impacts considered in the existing or prevailing analyses are associated with adverse effects on population, land use of cities, transportation and economy caused by different types of riverine and urban flooding, though coastal flooding, tsunami and storm surge effects are less studied. Mumbai and Kolkata are relatively progressive in the assessment of flood risks and adaptation. The present article also suggests strategies to evaluate the relative progress in the assessment of past and future risks and adaptation. We also discuss the mitigation and adaptation strategies considering the historical importance of these cities. We propose that the strategies should be implemented considering public opinion and should be initialized at the grass root level. Though it is technically difficult to re-plan the city structures in the current scenario, it is possible to adapt to and mitigate the effects of natural hazards through suitable planning and management with the integrated cooperation and involvement of citizens and government as well.

Ambient water quality is a prerequisite for the health and self-purification capacity of riverine... more Ambient water quality is a prerequisite for the
health and self-purification capacity of riverine ecosystems.
To understand the general water quality situation, the time
series data of selected water quality parameters were analyzed
in an urban river in Peninsular Malaysia. In this
regard, the stations were selected from the main stem of the
river as well as from the side channel. The stations located
at the main stem of the river are less polluted than that in
the side channel. Water Quality Index scores indicated that
the side channel station is the most polluted, breaching the
Class IV water quality criteria threshold during the monitoring
period, followed by stations at the river mouth and
the main channel. The effect of immediate anthropogenic
waste input is also evident at the side channel station. The
Organic Pollution Index of side channel station is (14.99)
*3 times higher than at stations at river mouth (4.11) and
*6 times higher than at the main channel (2.57). The twoway
ANOVA showed significant difference among different
stations. Further, the factor analysis on water quality
parameters yielded two significant factors. They discriminated
the stations into two groups. The land-use land cover
classification of the study area shows that the region near
the sampling sites is dominated by urban settlements
(33.23 %) and this can contribute significantly to the
deterioration of ambient river water quality. The present
study estimated the water quality condition and response in
the river and the study can be an immediate yardstick for
base lining river water quality, and a basis for future water
quality modeling studies in the region.

Drainage Morphometric analysis was carried out to assess the fluvial erosion susceptibility of wa... more Drainage Morphometric analysis was carried out to assess the fluvial erosion susceptibility of watersheds in Kangra region of Himachal Pradesh in India. The topographic maps and SRTM DEM were used as inputs for digitization of drainages and preparation of watershed boundaries, respectively. The linear, aerial and relief parameters of drainages were calculated for all the watersheds and weightages were assigned to them to derive Composite Weightage Values (CWV). Consequently, by way of grouping these values, the watersheds were categorized in to four classes such as low, medium, high and very high watershed erosion susceptibility. The analyses were conducted in Geographic Information System environment which, resulted in 10 watersheds in the study area, namely, 1B1A1, 1B1A2, 1B1B3, 1B1B4, 1B1B5, 1B1B6, 1B1B7, 1B1C8, 1B1C9 and 1B1C10. Among these, the watersheds 1B1A2 (Chakki-Jabban) and 1B1B5 (Dehar) were concluded as most susceptible to stream erosion followed by 1B1A1, 1B1B3, 1B1B7, 1B1B4-1B1B6-1B1C10, 1B1C9 and 1B1C8. The correlation of CWV with morphometric parameters showed that the high stream frequency, coarser texture, high relief and low length of overland flow control the drainage pattern in the region. It was also observed that among land use/ land cover, agriculture land is major factor governing soil erosion. Geologically, it is influenced mainly by the Quaternary Alluvium and unconsolidated rock formations of the terrain. It was revealed that 17.78 % of the study area is prone to very high erosion, 21.54 % is prone to high erosion, 43.11 % is prone to medium erosion, and 17.57 % area is prone to low erosion. It is therefore suggested that the soil and water conservation measures are required in the watersheds to control the fluvial erosion.

A study was carried out in Kangra district of Himachal Pradesh in Indian western Himalaya to unde... more A study was carried out in Kangra district of Himachal Pradesh in Indian western Himalaya to understand feasibility of automated and manual watershed boundary delineation. It was observed that manual preparation of these boundaries are tedious, time consuming and require base inputs in terms of topographic maps. It is done by skilled user. The automated approach for watershed delineation is simpler as comparison, and can be carried out using open source software and freely available database as inputs. The results showed that the automated watershed boundaries were accurate, smooth and faster in processing. The automated approach is advantageous in mountainous complex terrain drained by numerous smaller tributaries.

One of the major requirements of planning coastal protection works is to understand the processes... more One of the major requirements of planning coastal protection works is to understand the processes of erosion, deposition, sediment transport, flooding and sea level changes which continuously alter the shoreline. Significant erosion can affect the stability and productivity of aquatic environment which may have severe implications for coastal inhabitants. The middle coastal plains of Odisha State on the east coast of India were investigated for morphological assessment of shoreline. Accurate demarcations of shorelines were carried out at parts of Odisha coast specifically along Gahirmatha, Paradip and coast above Devi River to quantify erosion and accretion at annual to decadal scale for the years 1990, 2000 and 2012. Satellite-derived remote sensing data (Landsat and IRS P6) were used in the study. Digital shoreline analysis system discovered the eroded and accreted parts of the study area. Gahirmatha and coast above Devi River experienced heavy erosion during 2000–2012 compared with 1990–2000, whereas Paradip coast has comparatively undergone accretion during 2000–2012. Some accreted spots are identified nearby river mouths, which are attributed to heavy accretion of eroded materials by the action of sediment transport. The detailed analysis reveals a maximum erosion of 124, 33 and 154 m in a decade at Gahirmatha, Paradip and coast above Devi River, respectively. Southern parts of Gahirmatha coast showed highly dynamic behavior near Hukitola Bay and Barrier Island and are acting as a natural breakwater to conserve the shoreline. This region had undergone severe geomorphologic changes due to natural as well as human interventions and poses a threat. This coast exhibits unique reasons for erosion with various degrees of combinations of sediment depletion, human activities, high frequency of cyclones and floods, sea level rise, etc. This study concludes that the shoreline of Odisha coast is under heavy erosion and needs scientific and management attention.

Conference Presentations by Ravinder Dhiman

Coastal erosion is one of the major problems of the coastal zone. The erosion is triggered by var... more Coastal erosion is one of the major problems of the coastal zone. The erosion is triggered by various reasons such as high wave energy, reduction of sediments, natural disasters and climate change etc. In the era of industrialization, major infrastructure developments are happening along the coast. Prior to the initiation of those projects, it is important to understand the coastal processes of erosion, deposition, sediment-transport, flooding and sea-level-changes of the region which continuously alters the shoreline. These processes disturb the stability and productivity of aquatic environment and may have severe implications for proprietors. This study attempts morphological assessment of shoreline in the middle coastal plains of Odisha state on the east coast of India. Shorelines changes study is carried out at Dhamra and Maipura Coast to quantify erosion and accretion during years 1990 – 2012. Satellite derived remote sensing data of LANDSAT and IRS P6 for the years 1990, 2000 and 2012 were used in this study. Dhamra coast has been modified in between these years due to anthropogenic disturbance such as port development. Maipura coast which has large mangrove cover, Bhitarkanika national park carries its ecological importance. These coasts experienced erosion during 2000-2012 compared to 1990-2000. Accretion is noticed in the nearby river mouths. Temporal variation of sediments and frequent flood events will also be discussed in the paper. The detailed analysis reveals that the maximum erosion of 227 m, 47 m in a decade at Dhamra and Maipura coasts respectively. Area of Dhamra coast was under accretion during 1990-2000 and this area experienced erosion near Dhamra port just after the development of port in 2007. This study concludes that shoreline of study area is under high risk of erosion and inundation due to natural as well as anthropogenic activities in the area.

Environmental Science and Pollution Research

Journal of Coastal Conservation

Ocean & Coastal Management

Applied Water Science