Dynamic shoreline alterations and their impacts on Olive Ridley Turtle (Lepidochelys olivacea) nesting sites in Gahirmatha Marine Wildlife Sanctuary, Odisha (India).

Currently, sea turtle habitats are being altered by climate change and human activities, with habitat loss posing an urgent threat to Indian sea turtles. Thus, the objective of this study is to analyze the dynamic shoreline alterations and their impacts on Olive Ridley Sea Turtle (ORT) nesting sites in Gahirmatha Marine Wildlife Sanctuary from 1990 to 2022. Landsat satellite images served as input datasets to assess dynamic shoreline changes. This study assessed shoreline alterations and their rates across 929 transects divided into four zones using the Digital Shoreline Analysis System (DSAS) software. The results revealed a significant 14-km northward shift in the nesting site due to substantial coastal erosion, threatening the turtles' Arribada. This study underscores the need for conservation efforts to preserve nesting environments amidst changing coastal landscapes, offering novel insights into the interaction between coastal processes and marine turtle nesting behaviors.

Climate change and resilience, adaptation, and sustainability of agriculture in India: A bibliometric review.

Climate change (CC) is a global issue, with effects felt across nations, including India. The influences of CC, such as rising temperatures, irregular rainfall, and extreme weather events, have a direct impact on agricultural productivity, thereby affecting food security, income, livelihoods, and overall population health. This study aims to identify trends, patterns, and common themes in research on Climate Change and Resilience, Adaptation, and Sustainability of Agriculture in India (CCRASAI). It also seeks to illuminate potential future research directions to guide subsequent research and policy initiatives. The adverse impacts of CC could push farmers into poverty and undernourishment, underscoring the imperative to focus on the resilience, adaptation, and sustainability of agriculture in India. A bibliometric review was conducted using Biblioshiny and VoSviewer software to analyze 572 articles focused on CCRASAI from the Scopus and Web of Science databases, published between 1994 and 2022. There was an evident upward trend in CCRASAI publications during this period, with steady growth appearing after 2007. Among the States and Union Territories, Delhi, Tamil Nadu, West Bengal, Andhra Pradesh, and Karnataka have the highest number of published research articles. Research on CCRASAI is most concentrated in the southern plateau, the trans-Gangetic and middle Gangetic plains, and the Himalayan regions. The frequently used terms-'climate change impacts,' 'adaptation strategies,' and 'sustainable agriculture'-in CCRASAI research emphasize the focus on analyzing the effects of CC, creating adaptation strategies, and promoting sustainable agricultural practices.

Spatial analysis and machine learning prediction of forest fire susceptibility: a comprehensive approach for effective management and mitigation.

Forest fires (FF) in tropical seasonal forests impact ecosystem. Addressing FF in tropical ecosystems has become a priority to mitigate impacts on biodiversity loss and climate change. The escalating frequency and intensity of FF globally have become a mounting concern. Understanding their tendencies, patterns, and vulnerabilities is imperative for conserving ecosystems and facilitating the development of effective prevention and management strategies. This study investigates the trends, patterns, and spatiotemporal distribution of FF for the period of 2001-2022, and delineates the forest fire susceptibility zones in Odisha State, India. The study utilized: (a) MODIS imagery to examine active fire point data; (b) Kernel density tools; (c) FF risk prediction using two machine learning algorithms, namely Support Vector Machine (SVM) and Random Forest (RF); (d) Receiver Operating Characteristic and Area Under the Curve, along with various evaluation metrics; and (e) a total of 19 factors, including three topographical, seven climatic, four biophysical, and five anthropogenic, to create a map indicating areas vulnerable to FF. The validation results revealed that the RF model achieved a precision exceeding 94 % on the validation datasets, while the SVM model reached 89 %. The estimated forest fire susceptibility zones using RF and SVM techniques indicated that 20.14 % and 16.72 % of the area, respectively, fall under the "Very High Forest Fire" susceptibility class. Trend analysis reveals a general upward trend in forest fire occurrences (R2 = 0.59), with a notable increase after 2015, peaking in 2021. Notably, Angul district was identified as the most affected area, documenting the highest number of forest fire incidents over the past 22 years. Additionally, forest fire mitigation plans have been developed by drawing insights from forest fire management strategies implemented in various countries worldwide. Overall, this analysis provides valuable insights for policymakers and forest management authorities to develop effective strategies for forest fire prevention and mitigation.

Trade Off between Hydrodynamic and Thermodynamic Forces at the Liquid-Liquid Interface.

Viscous fingering (VF) instability has been investigated in the case of a partially miscible binary system by nonlinear numerical simulations. Partially miscible fluid systems offer the possibility of phase separation coupled with VF instability. The thermodynamics of such systems are governed by the Margules parameter (interaction parameter) as well as the fluid concentrations. Kinetics of the decomposition is also influenced by dynamical parameters such as the viscosity of the fluid, which incidentally also affects the hydrodynamic forces. Here, we explore the effects of concentration and Margules parameter in order to ascertain the trade-offs incurred between hydrodynamic and thermodynamic effects at the interface as well as the thermodynamics of the bulk. Based on the Gibb's free energy versus concentration curve, we select concentrations (i) outside spinodal and binodal regions, (ii) within binodal but outside the spinodal, and (iii) within the spinodal curve. We solve the modified Cahn-Hilliard-Hele-Shaw equation employing the COMSOL Multiphysics software. Applying high-resolution numerical simulations, we show a strong dependence of the thermodynamic forces on the concentration of the mixtures. Rapid phase separation and hence a faster rate of droplet formation have been found when the concentration lies inside the spinodal region. Further, we have investigated the correlation between the fractal dimension and dynamics of the system. The spatiotemporal studies presented in this work clearly illustrate the competition between hydrodynamic and thermodynamic forces and provide insights on the kinetics of decomposition and growth of interfacial instabilities.

A multi-temporal analysis of shoreline dynamics influenced by natural and anthropogenic factors: Erosion and accretion along the Digha Coast, West Bengal, India.

This investigation analyzed shoreline evolution along India's Digha Coast from 1992 to 2022, using multispectral Landsat satellite images and the Digital Shoreline Analysis System (DSAS). Methods included identifying zones and transects, shoreline extraction, and applying spatial statistical techniques. The study area, divided into five zones with 587 transects, enabled both short- and long-term analysis. Key findings indicate that the mean long-term rate of shoreline change is -0.54 m per year, with 70.70 % of transects experiencing erosion and 29.30 % accretion. Notably, Zone V had the highest accretion rate (8.55 m/year), while Zone III faced the most erosion (-7.47 m/year). Short-term analysis from 1997 to 2017 indicated significant erosion, contrasting with accretion during 1992-1997 and 2017-2022. Particularly, Zones II, III, and IV underwent major erosion, especially from 1997 to 2002. The study underscores the need for continuous shoreline management strategies and demonstrates geospatial technology's effectiveness in capturing coastal landscape changes.

Current patterns and trends of microplastic pollution in the marine environment: A bibliometric analysis.

Microplastics are pervasive in the natural environment and pose a growing concern for global health. Plastic waste in marine environments has emerged as a global issue, threatening not only marine biota but also human health due to its implications for the food chain. This study aims to discern the patterns and trends of research, specifically on Marine Microplastic Pollution (MMP), based on a bibliometric analysis of scientific publications from 2011 to 2022. The methodology utilized in this study comprises three stages: (a) creating a bibliographical dataset from Scopus by Elsevier and the Web of Science Core Collection by Clarivate Analytics, (b) analyzing current research (trends and patterns) using bibliometric analysis through Biblioshiny tool, and (c) examining themes and subthemes in MMP research (wastewater treatment, plastic ingestion, the Mediterranean Sea, microplastics pollution, microplastics in freshwater, microplastic ingestion, plastic pollution, and microplastic pollution in the marine environment). The findings reveal that during the studied period, the number of MMP publications amounted to 1377 articles, with an average citation per publication of 59.23 and a total citation count of 81,553. The most cited article was published in 2011, and since then, the number of publications on this topic has been increasing steadily. The author count stood at 5478, with 22 trending topics identified from the 1377 published titles. Between 2019 and 2022, the countries contributing most to the publication of MMP articles were China, the United States of America (USA), and the United Kingdom (UK). However, a noticeable shift in the origin of author countries was observed in the 2019-2022 timeframe, transitioning from a dominance by the USA and the UK to a predominance by China. In 2019, there was a substantial increase in the volume of publications addressing the topic of microplastics. The results show that the most prevalent themes and subthemes pertained to MMP in the Mediterranean Sea. The journals with the highest number of MMP articles published were the Marine Pollution Bulletin (253 articles) and Science of the Total Environment (190 articles). The analysis concludes that research on MMP remains prominent and appears to be increasing each year.

Radiation effect on stagnation point flow of Casson nanofluid past a stretching plate/cylinder.

The exclusive behaviour of nanofluid has been actively emphasized due to the determination of improved thermal efficiency. Hence, the aim of this study is to highlight the laminar boundary layer axisymmetric stagnation point flow of Casson nanofluid past a stretching plate/cylinder under the influence of thermal radiation and suction/injection. Nanofluid comprises water and Fe3O4 as nanoparticles. In this article, a novel casson nanofluid model has been developed and studied on stretchable flat plate or circular cylinder. Adequate rational assumptions (velocity components) are employed for the transformation of the governing partial-differential equations into a group of non-dimensional ordinary-differential formulas, which are then solved analytically. The momentum and energy equations are solved through the complementary error function method and scaling quantities. Using various figures, the effects of essential factors on the nanofluid flow, heat transportation, and Nusselt number, are determined and explored. From obtained results, it is observed that the velocity field diminishes owing to magnification in stretching parameter [Formula: see text] and Casson fluid parameter [Formula: see text]. The temperature field increases by amplifying radiation [Formula: see text], and solid volume fraction parameter [Formula: see text]. The research is applicable to developing procedures for electric-conductive nanomaterials, which have potential applications in aircraft, smart coating transport phenomena, industry, engineering, and other sectors.

Coastal evolution and future projections in Conde County, Brazil: A multi-decadal assessment via remote sensing and sea-level rise scenarios.

Global sea levels, having risen by approximately 20 cm since the mid-19th century, necessitate a critical examination of their impacts on shoreline dynamics. This research evaluates the historical (1985-2022) and future shoreline changes in Conde County, Paraíba State, Brazil, an area of significant touristic interest. Employing Landsat satellite imagery, the study utilized the Digital Shoreline Analysis System (DSAS) and a Kalman filter algorithm for cloud removal, while also assessing land use and land cover changes using data from the MapBiomas Project for 2000, 2010, and 2020. These analyses informed projections of potential inundation under various sea-level rise (SLR) scenarios: 1, 2, 5, and 10 m. Key findings revealed a negative average coastline change rate of -0.27 m/year from 1985 to 2022, indicative of erosive trends likely accelerated by human activities. Long-term projections for 2032 and 2042 anticipate continued erosion in areas identified as highly vulnerable. The SLR scenario analysis underscores the urgent need for adaptive climate measures; while a 1- or 2-meter SLR presents limited immediate effects, a 5-meter rise could lead to significant inundation across key sectors, including urban and agricultural landscapes. The projected severity of a 10-meter SLR necessitates immediate, comprehensive interventions to safeguard both natural and human systems.

Geo-ecological, shoreline dynamic, and flooding impacts of Cyclonic Storm Mocha: A geospatial analysis.

This research comprehensively assesses the aftermath of Cyclonic Storm Mocha, focusing on the coastal zones of Rakhine State and the Chittagong Division, spanning Myanmar and Bangladesh. The investigation emphasizes the impacts on coastal ecology, shoreline dynamics, flooding patterns, and meteorological variations. Employed were multiple vegetation indices-Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Modified Vegetation Condition Index (mVCI), Disaster Vegetation Damage Index (DVDI), and Fractional Vegetation Cover (FVC)-to evaluate ecological consequences. The Digital Shoreline Assessment System (DSAS) aided in determining shoreline alterations pre- and post-cyclone. Soil exposure and flood extents were scrutinized using the Bare Soil Index (BSI) and Modified Normalized Difference Water Index (MNDWI), respectively. Additionally, the study encompassed an analysis of microclimatic variables, comparing meteorological data across pre- and post-cyclone periods. Findings indicate significant ecological impacts: an estimated 8985.46 km2 of dense vegetation (NDVI >0.6) was adversely affected. Post-cyclone, there was a discernible reduction in EVI values. The mean mVCI shifted negatively from -0.18 to -0.33, and the mean FVC decreased from 0.39 to 0.33. The DVDI underscored considerable vegetation damage in various areas, underscoring the cyclone's extensive impact. Meteorological analysis revealed a 245 % increase in rainfall (20.22 mm on May 14, 2023 compared to the May average of 5.86 mm), and significant increases in relative humidity (14 %) and wind speed (205 %). Erosion was observed along 74.60 % of the studied shoreline. These insights are pivotal for developing comprehensive strategies aimed at the rehabilitation and conservation of critical coastal ecosystems. They provide vital data for emergency response initiatives and offer resources for entities engaged in enhancing coastal resilience and protecting local community livelihoods.

Momentum transport of morphological instability in fluid displacement with changes in viscosity.

Saffman-Taylor instability exhibits a stepwise unstable morphology from a stable interface to viscous fingering, eventually leading to tip splitting. The nonlinear dynamics of the destabilized interface depends on various flow properties. However, the physicochemical mechanism that determines the transition point of the flow state is unclear. We studied the interfacial instability transition in miscible displacement from a thermodynamic perspective by calculating the momentum transport and entropy production. Using numerical analysis based on Darcy's law coupled with the convection-diffusion equation, the observed flux-dependent flow state transitions were attributed to the selection of the flow state with a higher entropy production.

Remote sensing, GIS, and analytic hierarchy process-based delineation and sustainable management of potential groundwater zones: a case study of Jhargram district, West Bengal, India.

The present investigation delineates groundwater potential zones (GPZ) in the Jhargram district through an integrated approach employing analytical hierarchical process (AHP), remote sensing, and geographical information systems (GIS). Twelve parameters were utilized for GPZ analysis based on the Groundwater Potential Index, subsequent to multicollinearity testing. Classification of GPZ yielded five distinct categories: very poor, poor, moderate, good, and very good. Validation through receiver operating characteristics (ROC) and cross-validation with borewell yield data affirmed prediction accuracies of 78.4% and 84%, respectively. Spatial distribution analysis revealed that 30.39%, 30.86%, and 13.19% of the surveyed area fell within the poor, moderate, and good potentiality zones, respectively, whereas 15.86% and 9.69% were categorized as very poor and very good GPZs. Sensitivity analysis highlighted the significance of geology, elevation, geomorphology, slope, and lineament density as influencing parameters; elimination of any single parameter engendered significant alterations in the GPZ classification. The investigation culminated in the formulation of a block-wise sustainable groundwater management blueprint designed to inform policy initiatives.

Assessment of macrobenthos diversity and a zoning proposal for Seixas coral reefs (northeastern Brazil).

Coral reefs worldwide are under severe threat due to their inherent fragility and urgent need for conservation. The escalating tourism in coral reefs significantly impacts the marine ecosystem's biodiversity and conservation. This study analyzed the diversity and conservation status of macrobenthos in the Seixas coral reef, located in northeastern Brazil, and proposed a zoning plan. We employed monitoring protocols adapted from the Reef Check Program, the Rapid Assessment Protocol for Atlantic and Gulf Reefs, and the Protocol for Monitoring Coastal Benthic Habitats. Species identification was carried out by analyzing 25 transects, each divided into 1 m2 grids, with photos recorded for each grid, totaling 625 photos. Margalef, Shannon-Weaver, Simpson, and Pielou indices were used to analyze species distribution and diversity. The results indicated Dictyotaceae, Sargassaceae, and Corallinaceae as prevalent families. This research offers decision-makers a snapshot of species distribution in the Seixas coral reefs, providing a non-destructive, efficient methodology for assessing environmental impacts on coastal coral reefs.

A bibliometric analysis of sustainable development goals (SDGs): a review of progress, challenges, and opportunities.

The Sustainable Development Goals (SDGs) are a global appeal to protect the environment, combat climate change, eradicate poverty, and ensure access to a high quality of life and prosperity for all. The next decade is crucial for determining the planet's direction in ensuring that populations can adapt to climate change. This study aims to investigate the progress, challenges, opportunities, trends, and prospects of the SDGs through a bibliometric analysis from 2015 to 2022, providing insight into the evolution and maturity of scientific research in the field. The Web of Science core collection citation database was used for the bibliometric analysis, which was conducted using VOSviewer and RStudio. We analyzed 12,176 articles written in English to evaluate the present state of progress, as well as the challenges and opportunities surrounding the SDGs. This study utilized a variety of methods to identify research hotspots, including analysis of keywords, productive researchers, and journals. In addition, we conducted a comprehensive literature review by utilizing the Web of Science database. The results show that 31% of SDG-related research productivity originates from the USA, China, and the UK, with an average citation per article of 15.06. A total of 45,345 authors around the world have contributed to the field of SDGs, and collaboration among authors is also quite high. The core research topics include SDGs, climate change, Agenda 2030, the circular economy, poverty, global health, governance, food security, sub-Saharan Africa, the Millennium Development Goals, universal health coverage, indicators, gender, and inequality. The insights gained from this analysis will be valuable for young researchers, practitioners, policymakers, and public officials as they seek to identify patterns and high-quality articles related to SDGs. By advancing our understanding of the subject, this research has the potential to inform and guide future efforts to promote sustainable development. The findings indicate a concentration of research and development on SDGs in developed countries rather than in developing and underdeveloped countries.

Experimental demonstration of the suppression of viscous fingering in a partially miscible system.

Phase separation is ubiquitous in nature and technology. So far, the focus has primarily been on phase separation occurring in the bulk phase. Recently, phase separation taking place in interfacial areas has attracted more attention - in particular, a combination of interfacial phase separation and hydrodynamics. Studies on this combination have been conducted intensively in this past decade; however, the detailed dynamics remain unclear. Here, we perform fluid displacement experiments, where a less viscous solution displaces a more viscous one in a radially confined geometry and phase separation occurs at the interfacial region. We demonstrate that a finger-like pattern, due to the viscosity contrast during the displacement, can be suppressed by the phase separation. We also claim that the direction of a body force, the so-called Korteweg force, which appears during the phase separation and induces convection, determines whether the fingering pattern is suppressed or changed to a droplet pattern. The change of the fingering pattern to the droplet pattern is enhanced by the Korteweg force directed from the less viscous solution to the more viscous one, whereas the fingering is suppressed by the force directed in the opposite direction. These findings will contribute directly to the higher efficiency of processes such as enhanced oil recovery and CO2 sequestration, where interfacial phase separation is considered to occur during the flow.

Quantitative assessment of present and the future potential threat of coastal erosion along the Odisha coast using geospatial tools and statistical techniques.

The eastern coast of India is one of the regions where most of the population resides in urban areas in the low-elevation coastal zone, making it vulnerable to frequent extreme weather events. The objectives of this study are to assess the short- to long-term shoreline changes of the Odisha coast, to understand how anthropogenic influences, and particularly extreme natural events, affect these changes, and to predict shoreline changes for 2050. This study utilized multi-temporal/spectral/spatial resolution satellite images and a digital shoreline analysis (DSAS) tool to appraise the short- (at five/six-year intervals) and long-term (1990-2019) shoreline dynamics along the coastal part of Odisha over the past three decades (1990-2019). The long-term shoreline analysis shows that the mean shoreline change is about 0.67 m/year and highlights that 52.47 % (227.4 km), 34.70 % (150.4 km), and 12.83 % (55.6 km) of the total Odisha coastline exhibit erosion, accretion, and stability, respectively. During the short-term analysis, the 2000-2005 period had the highest percentage of erosion (64.27 %), followed by the 2005-2010 period with an erosional trend of 59.06 %. The 1995-2000 period showed an accretion trend, whereas, during the last period, i.e., 2015-2019, the percentage of transects depicting erosion and accretion was almost similar. In 2050, 55.85 % of the transects are expected to show accretion, while 44.15 % would show erosion or a constant trend. The study identified the hotspots of coastal erosion along delineated study zones by synthesizing data from previous studies as well. The regional analysis of shoreline change along the Odisha coast would not only provide coastal managers with critical information on shoreline dynamics but also draw attention to vulnerable areas linked to shoreline dynamicity along the coast.

Deciphering the impact of anthropogenic coastal infrastructure on shoreline dynamicity along Gopalpur coast of Odisha (India): An integrated assessment with geospatial and field-based approaches.

Odisha's coastline supports various development activities that are critical to the state and national economy, such as oil and gas, ports and harbors, power plants, fishing, tourism, and mining that continues to not only detriment the coastal ecology but also affect the overall shoreline morphodynamics. The morphological changes are complicated processes involving both natural and human-induced drivers, but it is critical to understand how recent development activities further impact beach morphodynamics and shoreline dynamicity. The study analyzes the overall shoreline morphodynamics in response to the recent development of port and other related infrastructure for annual and decadal scale using two-dimensional (2-D) shoreline changes along with detailed 3-D beach profile volumetric changes for different studied zones along the Gopalpur coast. The results reveal that nearly all studied zones of the Gopalpur shoreline, Zone-4 (EPR = -05.64 m a-1 and LRR = -04.25 m a-1), Zone-3 (EPR = -04.51 m a-1 and LRR = -07.01 m a-1) and Zone-1 (EPR = -2.85 m a-1 and LRR = -01.46 m a-1), experienced erosion between 2010 and 2020 except Zone-2 (EPR = 24.31 m a-1 and LRR = 25.96 m a-1), which showed overall sign of deposition. The interannual shoreline analysis depicted that Zone-1 (tourist beach area) remained almost stable, Zone-2 (south of the breakwater of Gopalpur Port) showed accretion trends, Zone-4 (north side of the port) dominantly showed an erosion pattern, whereas Zone-3 (port area) showed a high level of uncertainty in the context of erosional or deposition trends. Calculated volumetric loss along the surveyed 3-D beach profiles supports these 2-D changes for all the studied zones. The results showed substantial changes in coastal morphodynamics in different studied zones of the Gopalpur region and severe erosion along its northern segment of the constructed coastal infrastructure. These findings can potentially promote effective coastal zone management and prevent further deterioration along the Gopalpur coast in future.

Effect of Hele-Shaw cell gap on radial viscous fingering.

The flow through a Hele-Shaw cell is an experimental prototype to study the flow through a porous medium as well as the flow in microfluidic devices. In context with porous medium flows, it is used to visualize and understand hydrodynamic instabilities like viscous fingering (VF). The gap between the plates of the cell is an important parameter affecting the flow dynamics. However, the effect of the gap on the Hele-Shaw cell flows has been minimally explored. We perform experiments to understand the effect of the gap on VF dynamics. It is observed that a minimum gap is required to observe rigorous fingering instability. The onset time of instability, as well as the width of the fingers, increases with an increment in the gap due to a decrease in the convection. The instability increases with an increase in Péclet number, but the effect of gap width on fingering patterns is evident with broader fingers observed for larger b. The results are validated by performing numerical simulations. It is further shown that the gap-averaged three-dimensional simulations using the Stokes law approach and the two-dimensional Darcy's law result in a small gap Hele-Shaw cell.

Characterizing global satellite-based indicators for coastal vulnerability to erosion management as exemplified by a regional level analysis from Northeast Brazil.

The detection of coastal vulnerability to erosion is crucial for decision-making regarding the economy, ecology, health, security, among other issues. Most of the studies gather a large data set about physical and anthropogenic interference's on the vulnerability of coastal erosion regions around the world. However, for developing nations like Brazil, with extensive shoreline, it is challenging to develop and maintain an in situ infrastructure to offer a systematical scientific data set. In this context, several methods like Coastal Vulnerability Index (CVI) for monitoring the dynamic behavior of coastal systems require in situ collected data. Therefore, this contribution explores the use of global open source satellite-based indicators to assess coastal vulnerability to erosion at a regional level adopting an uncorrelated orthogonal basis set of Principal Component Analysis (PCA). For this, the data set covers many spheres of the environment like biophysical and social factors, adopting the Pernambuco State's coast, Brazil, as a case study. The results showed the direct relationship between a high level of urbanization and low vegetation with the high coastal vulnerability to erosion. PC1 revealed built-up and surface temperature vary inversely to the soil organic carbon and vegetation cover along about 20 km (≈10% of the shoreline extension). The hotspots were in the urban cluster (Paulista, Olinda, Recife, and Jaboatao dos Guararapes), combined with high shoreline change around -2 m/yr. PC2 showed the natural action of wind on wave heights combined with sediment removal and the backshore settlement along 10 km of extension (≈5.5% of the shoreline), with the highly vulnerable sites concentrated in Itamaraca Island and C. S. Agostinho. This approach benefits from the multi-satellite and multi-resolution data sets integration to unravel the statistical influence of each variable able to guide stakeholders.

Assessment of impacts to the sequence of the tropical cyclone Nisarga and monsoon events in shoreline changes and vegetation damage in the coastal zone of Maharashtra, India.

The tropical cyclones impact both the eastern and western coasts of India, causing severe socio-environmental problems. This study analyzed shoreline changes and vegetation degradation caused by cyclone Nisarga and monsoon events in Maharashtra coastal zone and Mumbai region, India. In this study, the shoreline change was studied using the Net Shoreline Movement (NSM) statistical technique embedded in the digital shoreline analysis system (DSAS) tool. The effects of the cyclone on the vegetation were mapped using the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and the rainfall distribution from Global Precipitation Measurement (GPM) data. The correlation between rainfall data and vegetation loss was analyzed using geographically weighted regression. The results also show that 90% of the events were concentrated in the 80-300 mm classes, being classified as sudden increases. This cyclone caused erosion in 56.32% of the shoreline; the highest erosion level was observed along the coastal zone of Maharashtra (near Mumbai city). Cyclone Nisarga has also impacted the vegetation loss most prominently in the region, with mean EVI in pre-cyclone equal to 0.4 and post-cyclone equal to 0.2. These eco-physical studies using geospatial technology are needed to understand the behavior of changes in shoreline and vegetation and can also help coastal managers plan for resilient coastal systems after the passage of tropical cyclones.

Response of long- to short-term tidal inlet morphodynamics on the ecological ramification of Chilika lake, the tropical Ramsar wetland in India.

The long- to short-term morphodynamic response in low-lying coastal wetlands raises serious concerns worldwide about the loss of their biodiversity and ecological ramifications due to change in tidal amplitude and cyclonic events. One such place worth studying is Chilika lake, India, a prominent Ramsar site, the largest brackish water lagoon in Asia, and the second-largest coastal lagoon in the world. It experiences frequent cyclone landfalls and strong littoral drift that tends to open/close the tidal inlet. The goal of this study was to analyze the response of slow onset events such as long- (1952-2020) to short-term (~annual scale from 1989 to 2020) tidal inlet movement, shoreline change (1990-2020 with almost every five-year interval), spit morphodynamics (~annual scale from 1989 to 2020) on ecological ramification in Chilika lake as well as the implications of sudden onset event such as cyclonic landfall. In this study, we used the Digital Shoreline Change Analysis System (DSAS) to compute the statistics of shoreline change rate by calculating end point rate (EPR) values for short-term shoreline change (1990, 1995, 2000, 2005, 2011, 2016, and 2020) and weighted linear regression (WLR) for long-term shoreline change (1990-2020). The results show that Chilika lake experienced both erosion and accretion processes with a remarkably high erosion rate of 19.87 m year-1 and accretion of 16.91 m year-1 during a long-term scale (1990-2020). The average erosion and accretion rates were 2.25 m year-1 and 4.67 m year-1, respectively, during the past three decades (1990-2020). The short-term analysis suggests that the highest mean erosion of 4.37 m year-1 occurred during 2005-2011, mainly due to cyclonic storms, reduction in sediment discharge, and lunar eclipse, which induced tide with very high amplitude in August 2008. Overall, the annual scale analysis of tidal inlet shows a shifting trend towards the northward side even after the artificial opening of an inlet in 2000. It can be ascribed mainly to the prevalent direction of longshore drift along this coast. This study observed that the landfall of cyclones significantly affects the spit morphodynamics and opening of the tidal inlet, which defines the inflow of the seawater into the lagoon and further substantial impacts on the ecological ramification. The current study's methodology can be extended to comprehend the response of long- to short-term changes of the tidal inlet, shoreline, and spit morphodynamics on the ecological ramification of coastal lagoons worldwide along with impacts of sudden-onset events caused by cyclonic landfall.