Browsing by Author "Purabi Saikia"

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Adapting to anomalous floods in Kaziranga National Park: ecosystem-based disaster risk reduction linking climate change to conservation strategies
(Elsevier, 2025) Preet Lal; Alisha Prasad; Purabi Saikia; Amit Kumar
Kaziranga National Park (KNP) in Assam, is a UNESCO world heritage site, which primarily affected by recurrent devastating floods over the last few decades. KNP is home to two-thirds of the world’s great one-horned rhinoceroses (Rhinoceros unicornis) population that is under high anthropogenic pressures and abiotic stresses. KNP falls within the Asian monsoon zone, and receiving a large amount of rainfall during premonsoon to postmonsoon periods leads to frequent flooding in the region that impacts human life, wildlife habitat, and overall ecosystem health. The present chapter attempted to discuss the precipitation and surface runoff anomaly in the Brahmaputra basin to deduce its possible relation with the recurrent floods in the region. The temporal Synthetic Aperture Radar (SAR) satellite images were used to infer the nature and coverage of inundation in KNP during 2015-19. The study suggested the increased frequency of floods due to anomalous rainfall in the region as well as in its upper catchment attributed to rising temperatures in major parts of India as an impact of changing climatic conditions. Effective ecosystem-based disaster risk reduction (EbDRR) strategies are required to reduce the increasing impacts of the devastating floods in KNP based on unique local traditional and ecological knowledge to cope with their own agro-ecological and socio-economic conditions. Therefore, various methods of EbDRR including the development of suitable habitats in the southern highlands, its linkages with KNP using a few overhead passages, extended buffer area in the vicinity of KNP to refrain from anthropogenic influences, and afforestation primarily in the northern and northeastern parts of KNP, are required to mitigate the flood hazard in KNP to secure the wildlife habitat in this world heritage site. © 2025 Elsevier Inc. All rights reserved.
Assessing population diversity and compositional structure in forests in Pachmarhi Biosphere Reserve, Central India
(Ecological Society of China, 2024) Gajendra Kumar; Amit Kumar; Purabi Saikia; M.L. Khan
The escalating impact of anthropogenic and climatic forces on forest bioresources poses significant challenges to the effective implementation of forest management plans, necessitating rigorous field investigations to provide the precise data required for developing effective conservation policies and ensuring ecosystem stability. This study addresses this need by presenting a comprehensive, field-based baseline framework that evaluates the effects of anthropogenic disturbances on floristic composition, tree diversity, and regeneration dynamics across tropical deciduous forest patches in Central India. Using a stratified random sampling approach with belt transects in 62 sites (0.5 ha each), the research documents 190 plant species, including 85 trees, 23 shrubs, and 82 herbs, with 37.89% listed on the IUCN Red-List, underscoring their conservation significance in Pachmarhi Biosphere Reserve (PBR). The findings reveal moderate tree density in the forests (386 individuals per hectare) dominated by Chloroxylon swietenia, and statistically significant correlations between disturbance index and biodiversity metrics including indices of diversity (H′), dominance (CD), evenness (E) and richness i.e., Dmg and Dmn. The study highlights a concerning trend of either poor or no regeneration in 67% of tree species in PBR, linked to increasing anthropogenic pressures such as logging and fuelwood collection. The study also recorded 737 cut stumps across 45 forest patches (72.58%), with a disturbance index of 5.54, signaling an urgent need for conservation interventions. This research provides critical baseline data on the floristic composition and species richness of these forests, offering valuable insights for developing effective management strategies. Sustainable biodiversity management in the Biosphere Reserve requires targeted rehabilitation, protection, and intensive regeneration efforts to preserve this ecologically rich yet vulnerable ecosystem. © 2024 Ecological Society of China
Climate change and cities: Impacts and sustainable solutions
(Elsevier, 2025) Manjari Upreti; Purabi Saikia; Amit Kumar
Climate change has a wide range of effects on cities as they are more susceptible to catastrophic weather events due to shifting precipitation patterns, rising temperatures, and rising sea levels due to increased population, infrastructure, and economic activity. Increased heat, for instance, can make heat waves more frequent and intense, putting people at risk for dehydration, heat exhaustion, and heatstroke. Alterations in precipitation patterns can raise the danger of landslides and floods, which can destroy infrastructure and result in fatalities. Another effect of climate change, sea-level rise, puts low-lying places in danger of flooding and erosion. Climate change can also worsen already-existing social and economic disparities, thereby impacting particularly vulnerable groups such as low-income citizens, the elderly, and communities of color. Many sustainable solutions are being put into practice in cities all around the world to address these issues. Urban design techniques that support resilient and low-carbon urban infrastructure, such as green roofs and sustainable transportation networks, are some of these options. In order to lower greenhouse gas emissions and advance energy independence, sustainable energy solutions such as renewable energy and energy-efficient buildings are also being embraced at an increasing rate. © 2026 Elsevier Inc. All rights reserved.
Cultural ecosystem services of protected areas: considering community preferences and their socio-economic conditions
(Elsevier, 2025) Subhashree Patra; Purabi Saikia; Amit Kumar
Socioeconomic considerations have a considerable impact on both the adoption of cultural ecosystem services (CESs) and community preferences. Protected areas (PAs), which usually have a rich cultural legacy and provide possibilities for a variety of cultural activities, are crucial for maintaining these CESs. Some characteristics, such as economic position, educational attainment, and employment prospects, influence how local communities engage with PAs. Communities with little economic resources rely heavily on CESs for survival, whereas those with higher means may place a greater emphasis on recreational activities. Understanding community preferences is critical for better and more successful administration and maintenance of PAs. The linkages between community preferences, socioeconomic considerations, and the distribution of CESs in PAs emphasize the critical role of local communities in the creation of management strategies and decision-making processes. Further understanding of CESs and their relationship to community decisions and socioeconomic situations for improved sustainability would require more scientific research and collaboration between stakeholders. © 2025 Elsevier Inc. All rights reserved.
Design and performance of the Climate Change Initiative Biomass global retrieval algorithm
(Elsevier B.V., 2024) Maurizio Santoro; Oliver Cartus; Shaun Quegan; Heather Kay; Richard M. Lucas; Arnan Araza; Martin Herold; Nicolas Labrière; Jérôme Chave; Åke Rosenqvist; Takeo Tadono; Kazufumi Kobayashi; Josef Kellndorfer; Valerio Avitabile; Hugh Brown; João Carreiras; Michael J. Campbell; Jura Cavlovic; Polyanna da Conceição Bispo; Hammad Gilani; Mohammed Latif Khan; Amit Kumar; Simon L. Lewis; Jingjing Liang; Edward T.A. Mitchard; Ana María Pacheco-Pascagaza; Oliver L. Phillips; Casey M. Ryan; Purabi Saikia; Dmitry Schepaschenko; Hansrajie Sukhdeo; Hans Verbeeck; Ghislain Vieilledent; Arief Wijaya; Simon Willcock; Frank Martin Seifert
The increase in Earth observations from space in recent years supports improved quantification of carbon storage by terrestrial vegetation and fosters studies that relate satellite measurements to biomass retrieval algorithms. However, satellite observations are only indirectly related to the carbon stored by vegetation. While ground surveys provide biomass stock measurements to act as reference for training the models, they are sparsely distributed. Here, we addressed this problem by designing an algorithm that harnesses the interplay of satellite observations, modeling frameworks and field measurements, and generated global estimates of above-ground biomass (AGB) density that meet the requirements of the scientific community in terms of accuracy, spatial and temporal resolution. The design was adapted to the amount, type and spatial distribution of satellite data available around the year 2020. The retrieval algorithm estimated AGB annually by merging estimates derived from C- and L-band Synthetic Aperture Radar (SAR) backscatter observations with a Water Cloud type of model and does not rely on AGB reference data at the same spatial scale as the SAR data. This model is integrated with functions relating to forest structural variables that were trained on spaceborne LiDAR observations and sub-national AGB statistics. The yearly estimates of AGB were successively harmonized using a cost function that minimizes spurious fluctuations arising from the moderate-to-weak sensitivity of the SAR backscatter to AGB. The spatial distribution of the AGB estimates was correctly reproduced when the retrieval model was correctly set. Over-predictions occasionally occurred in the low AGB range (<50 Mg ha−1) and under-predictions in the high AGB range (>300 Mg ha−1). These errors were a consequence of sometimes too strong generalizations made within the modeling framework to allow reliable retrieval worldwide at the expense of accuracy. The precision of the estimates was mostly between 30% and 80% relative to the estimated value. While the framework is well founded, it could be improved by incorporating additional satellite observations that capture structural properties of vegetation (e.g., from SAR interferometry, low-frequency SAR, or high-resolution observations), a dense network of regularly monitored high-quality forest biomass reference sites, and spatially more detailed characterization of all model parameters estimates to better reflect regional differences. © 2024 The Authors
Discussion of Eguchi’s Article in Sankhya A: Rao’s Quadratic Entropy in an Ecological Context
(Springer, 2025) Sandrine Pavoine; Purabi Saikia; Michael B. Bonsall; Arni S.R. Srinivasa Rao
This article is a discussion on Shinto Eguchi’s article published in Sankhya A (Eguchi 2025). © Indian Statistical Institute 2025.
Earth observations for urban policies and future pathways for urban environmental research
(Elsevier, 2023) Pawan Ekka; Manjari Upreti; Shilky; Purabi Saikia; Amit Kumar; Prem C. Pandey; Prashant K. Srivastava
Urban research is now evolving, and there are several challenges that need to be addressed in the near future, which has led to pathways for further development. The scientific community must consider a multitude of options for urban monitoring, evaluation, planning, and management. In this chapter, we have provided a brief overview of different models for urban studies and research based on Earth observation datasets. This chapter discusses a variety of potential research areas, including satellite-based monitoring of urban areas, IoT and cloud computing in urban management, and the use of machine learning in urban environmental research. In addition to digitization, the availability of big data sets, machine learning (ML), and artificial intelligence (AI) will revolutionize the way urban areas are analyzed and planned, opening up new possibilities for sustainable urban challenges. The chapter outlines qualitative and quantitative methods utilizing predictive models and scenario analysis for identifying and implementing urban environmental policies. The recommendations provided in this chapter can be used for further urban studies, research, and the development of smart and resilient cities. © 2024 Elsevier Ltd. All rights reserved.
Evaluating dominant tree species as bioindicators for urban air pollution mitigation in Ranchi, Eastern India
(Springer Science and Business Media Deutschland GmbH, 2025) Pawan Ekka; Purabi Saikia
Key message: Effective nature-based solutions for urban air pollution require understanding how season, site, and species affect tree tolerance. The complex interplay of biochemical parameters significantly impacts trees’ sensitivity and tolerance. Abstract: Evaluating dominant tree species as bioindicators can provide valuable insights for effective air pollution mitigation strategies in rapidly developing cities like Ranchi, Eastern India. The air pollution tolerance index (APTI), anticipated performance index (API), and dust capturing capacity (DCC) of dominant urban street trees in Ranchi were studied at control, heavy traffic, and industrial sites during pre- and post-monsoon seasons. APTI varied significantly across seasons (F1,25.43 = 27.24, p < 0.05), sites (F2,261.87 = 280.50, p < 0.05), and trees (F9,9.18 = 9.83, p < 0.05). APTI values were highest at industrial, followed by heavy traffic, and lowest at control sites. AA content was the most influential biochemical parameter associated with APTI, showing a statistically significant strong correlation (r = 0.819, p < 0.01). Street trees at industrial sites exhibited the highest APTI values (range: 15.11–19.99), followed by heavy traffic sites (12.79–18.30), and lowest at control sites (11.46–15.72). DCC also varied significantly across seasons (F1,0.321 = 17.40, p < 0.05), sites (F2,2.65 = 144.25, p < 0.05), and trees (F9,2.95 = 160.92, p < 0.05). The highest DCC was recorded in Melia azedarach (2.64 mg cm−2), followed by Bauhinia variegata (2.49 mg cm−2), and Bridelia retusa (2.13 mg cm−2). APTI, API, and DCC were significantly affected by seasons, sites, species, and their interactions with pollutants. These findings highlight the importance of APTI, API, and DCC as important indicators of the pollution mitigation abilities of different urban street trees to recommend for urban greening initiatives in rapidly urbanizing cities like Ranchi. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Evaluating the 2018 extreme flood hazard events in Kerala, India
(Taylor and Francis Ltd., 2020) Preet Lal; Aniket Prakash; Amit Kumar; Prashant K. Srivastava; Purabi Saikia; A.C. Pandey; Parul Srivastava; M.L. Khan
The very high anomalous precipitation (more than 500 mm) and release of water from reservoirs located in an upper catchment resulted in severe flood inundation situation in downslope regions of Kerala State in August 2018. In the present study, the satellite-based precipitation was analyzed on a daily to weekly basis during the flood duration in Kerala. The Tropical Rainfall Measuring Mission (TRMM) based precipitation pattern indicated very high rainfall (more than 60 mm day–1) in the central parts of Kerala on 14 and 15August 2018. The climate research unit (CRU) based long-term mean cumulative precipitation (1901-2017) indicated high (300-400 mm) to very high (more than 500 mm) anomalous precipitation in parts of Kerala during August 2018 leading to severe flood inundation in major parts of the state. The Sentinel-1A Synthetic Aperture Radar (SAR) based inundation mapping exhibited flooding of 1100.4 km2 area (5.80% of total area) during August 2018, which severely affected Alappuzha, Thrissur, and Kottayam districts. Cropland (218.69 km2), settlement (115.23 km2) and shrubland (79.46 km2) were the most affected land-use/land-cover in the region. The study warrants the restoration of ecological stability and augmentation of resilience to flooding hazard primarily in the upper catchments (the Western Ghats). © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Forest monitoring tools and techniques with special emphasis on tropical forests
(Elsevier, 2025) Pawan Ekka; Gajendra Kumar; A. Naga Lakshman Kumar; Purabi Saikia
Environmental researchers and forest practitioners have been using different traditional and advanced methods for forest surveillance, field mapping, and integrated information. The growing concern of threats to natural forests by landscape change, habitat and biodiversity loss, and climate change has shifted the monitoring and ground-truthing efforts toward digitization by transforming data acquisitions, analysis, and integrated research and development methods. Forest management practices through “Digitalization of forest” is a new way of forest conservation, monitoring, and ground truthing in recent years, creating opportunities to improve assessments and monitoring activity. Remote sensing is an omnipresent operational technology increasingly used in forest monitoring by various stakeholders. Integration of Wireless Sensor Networks (WSN), Artificial Intelligence (AI), Mobile mapping, and Open Data Platforms (ODPs) are important monitoring tools and techniques used by ecologists and conservation scientists for decision-making, prediction models, and restoration activities. The present chapter briefly discusses traditional and advanced forest monitoring and ground-truthing tools and techniques used for data acquisition and analysis in research and development. It also overviews major challenges and recent progress to further find opportunities by stakeholders and practitioners for additional investigation, advancements in research, development, and technology innovation. © 2026 Elsevier Inc. All rights reserved..
Forests and their role in achieving United Nations sustainable development goals
(Elsevier, 2025) Subhashree Patra; Purabi Saikia; Amit Kumar; Xiangdong Lei; Mohammed Latif Khan
Forests are vital for achieving the United Nations sustainable development goals (UN SDGs) due to varied ecological, economic, and social assistance. It has an integral role in addressing global concerns like food security, poverty alleviation, biodiversity loss, and climate action. Programs such as joint forest management, participatory forest management, and community as well as smallholder forestry play a significant role in enhancing productivity and economic growth of the region; such practices worldwide contributed a major part in achieving the UN SDGs by reducing unemployment and poverty, maintaining biodiversity, production, and consumption, etc. The production of nontimber forest products (NTFPs), timber harvesting, tourism, and timber-based enterprises were the significant factors contributing to sustainable economic growth and development. These approaches cumulatively contribute to several goals and targets of UN SDGs; therefore, considering the multitude of services provided by the forests, it is essential to conserve, protect, and manage through collaborative work, policy interventions, and sustainable practices that will mitigate climate change, promote food security, and conserve forests for future generations. © 2025 Elsevier Inc. All rights reserved.
Forests for Inclusive and Sustainable Economic Growth
(Elsevier, 2025) Purabi Saikia; Amit Kumar; Mohammed Latif Khan; Xiangdong Lei
Forests for Inclusive and Sustainable Economic Growth addresses all major issues surrounding forest resources, also including global examples, case studies, literature reviews, latest developments, and future research prospects. To enhance understanding, the content is enriched with maps, figures, tables, and colorful illustrations, making it accessible to a broad readership. Students specializing in forest ecology and researchers will discover a wealth of knowledge on critical topics such as major ecological disturbances, the role of forests in poverty reduction and livelihood security, as well as participatory forest management techniques, landscape restoration, forest policies, and nature-based solutions. Importantly, this comprehensive volume highlights the pivotal role of forests in fostering employment, income generation, and food security to support inclusive and sustainable economic growth. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Human-induced impacts on ecological infrastructure in the Himalayan urban agglomerations
(Ecological Society of China, 2023) Diksha; Amit Kumar; Purabi Saikia; Prashant Srivastava
The spatial dimensions of urban ecological services (UESs) transformation and population density in major Himalayan urban agglomerations (UAs) were analyzed to deduce the impacts of anthropogenic activities in recent decades (1991–2018). The multi-satellite-based study exhibited a remarkable increase (193 sq. km; 15%) in the built infrastructure and a significant decline (−24%) in the ecological infrastructure in the Himalayan UAs. The continuous anthropogenic influence on the Himalayan ecosystems in the last three decades has created severe socio-economic-ecological consequences that have largely impacted green infrastructure (GI), which is receptive to conversion to built infrastructure. The large-scale UES alteration was evident within larger cities in the western and central Himalayas, in contrast to the low transformation in Eastern Himalayan cities barring Shimla UA. The investigation highlights the rapid and haphazard population influx and urban growth that imposed a higher risk of natural hazards in the Eastern and Central Himalayan UAs and necessitated suitable policies to build an ecologically sustainable urban ecosystem. © 2023 Ecological Society of China
Identification of urban street trees for green belt development for optimizing pollution mitigation in Delhi, India
(Springer, 2024) Shilky; Ratul Baishya; Purabi Saikia
The current study evaluated the effects of air pollution on selected street trees in the National Capital Territory during the pre- and post-monsoon seasons to identify the optimally suitable tree for green belt development in Delhi. The identification was performed by measuring the air pollution tolerance index (APTI), anticipated performance index (API), dust-capturing capacity (DCC) and proline content on the trees. The APTI of street trees of Delhi varied significantly among different tree species (F11,88.91 = 47.18, p < 0.05), experimental sites (F3,12.52 = 6.65, p < 0.001) and between seasons (F1,31.12 = 16.51, p < 0.001), emphasizing the relationships between trees and other types of variables such as the climate and level of pollution, among other factors. This variability emphasizes the need to choose trees to use for urban greening in the improvement of air quality in different environments within cities. Ascorbic acid (AA) concentration and relative water content (RWC) had a strong influence on APTI with an extremely significant moderate positive correlation between AA concentration and APTI (r = 0.65, p < 0.001) along with RWC and APTI (r = 0.52, p < 0.001), indicating that higher levels of AA concentration and RWC are linked to increased air pollution tolerance. The PCA bi-plot indicates AA has poor positive loading coefficients with PC1 explaining 29.49% of the total variance in the dataset. The highest APTI was recorded in Azadirachta indica (22.01), Leucaena leucocephala (20.65), Morus alba (20.62), Ficus religiosa (20.61) and Ficus benghalensis (19.61), irrespective of sites and seasons. Similarly, based on API grading, F. religiosa and F. benghalensis were identified as excellent API grade 6 (81–90%), A. indica and Alstonia scholaris as very good API grade 5 (71–80%), M. alba, Pongamia pinnata and Monoon longifolium as good API grade 4 (61–70%) and Plumeria alba as moderate API grade 3 (51–60%) in different streets of Delhi. As these plants are indigenous to the region and hold significant socio-economic and aesthetic significance in Indian societies, they are advisable for avenue plantations as part of various government initiatives to support environmental sustainability. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Introduction to earth observation in urban monitoring
(Elsevier, 2023) Amit Kumar; Manjari Upreti; Pawan Ekka; Alisha Prasad; Purabi Saikia; Prashant K. Srivastava
The rapid urban growth and increasing demand for natural resources lead to the considerable environmental degradation and habitat loss. The application of earth observation-based methods enables a better understanding of urban complexity with different spatio-spectral resolutions at temporal scales and contributes to addressing the adverse ecological impacts. There is an urgent need to understand the interdependencies of ecological conditions and changing urban growth to formulate a city-specific framework for sustainable urban development. Therefore the present chapter elucidates the fundamental components of the urban system emphasizing the earth observation-based technologies available to assess the urban environmental conditions that help in defining the settlement pattern and segregation of different land cover features. The inclusion of advanced artificial intelligence and machine learning algorithms provides precision analysis for future predictions and formulation of mitigation strategies. Furthermore, it helps in the determination of factors responsible for urban risk and of societal importance as well as in the implementation of significant policies and reforms for sustainable urban planning, monitoring, and management. © 2024 Elsevier Ltd. All rights reserved.
Introduction to GPS/GNSS technology
(Elsevier, 2021) Amit Kumar; Shubham Kumar; Preet Lal; Purabi Saikia; Prashant K. Srivastava; George P. Petropoulos
Satellite-based navigation systems are one of the most indispensable technologies in the present-day world that have made a vast improvement since the day of its inception due to global availability of signal and performance. It allows measuring positions in real time with an accuracy of up to a few centimeters on the Earth. The advent of Global Positioning System (GPS) has led to technological revolutions in highly accurate navigation, positioning, and time that is being applied in various civilian, military, and scientific purposes. GPS works on the radio waves that are being transmitted from a space-based group of satellites to the terrestrial GPS receiver to deduce the exact position of the Earth. Although there are various errors related to clock errors, multipath error, receiver noise, and antenna phase center variations at satellite as well as receivers end, it is being resolved through technological advancement and methods. Incorporating both GPS and GLONASS constellations in the navigation system may significantly improve the accuracy of the navigational solution. This chapter aims to discuss the various concepts of GPS, including working principle, various errors, various Global Navigation Satellite System technologies evolving from GPS to Quasi-Zenith Satellite System, and its vivid applications. © 2021 Elsevier Inc. All rights reserved.
Invasive plant species and their impact on forest composition and regeneration in tropical deciduous forests of Palamau Tiger Reserve, Eastern India
(Springer Science and Business Media B.V., 2025) Subhashree Patra; Purabi Saikia
The present study determined the current status of understorey invasive plant species (IPSs) and their impact on the forest composition and regeneration of Palamau Tiger Reserve, Eastern India. Tree diversity was sampled in 63 random belt transects (0.50 ha each), while shrubs and herbs in 9 random quadrats of 5 m 5 m and 1 m 1 m, respectively. A sum of 177 plant species were recorded, of which 18 were IPSs with the predominance of the members of the family Asteraceae (7 spp.). In the shrub layer, IPSs contributed the highest density (~ 52% of the overall density), and their contribution in the herb layer (~ 30%) was also very promising. On the other hand, 2% of the forest patches in the shrub and 3% in the herb layer, showed equal distributions of tree saplings and seedlings with IPSs. In contrast, the majority showed an inversely proportional relationship. In the shrub layer, the diversity index and disturbance index revealed an extremely weak but highly significant negative association (R2 = 0.14; p < 0.01), while in the herb layer, the correlation was extremely weak and insignificant (R2 = 0.001; p = 0.78). Increased IPSs density poses an alarming threat to the growth and regeneration of tree saplings and seedlings as well as the understorey plant diversity. Therefore, there is an urgent need for policy intervention and also to manage and control IPSs to enhance the population and regeneration of important plant species of both economic and ecological significance to achieve the United Nations’ sustainable development goal (SDG)-15. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Kolkata’s green oasis: a comprehensive analysis of urban green spaces for ecosystem sustainability
(Springer, 2025) Poushali Biswas; Amit Kumar; Manjari Upreti; Gajendra Kumar; Purabi Saikia
In the present study, the impact of urban growth on green spaces in Kolkata Metropolitan City (KMC) was evaluated using the multi-temporal satellite observations spanning the last four decades (1990–2022). The study exhibited a rapid rise in urban areas (178.38% growth; net increase 498 sq.km), leading to a significant conversion of areas into moderate to very high built-up density zones. This urbanization has markedly altered the green–blue infrastructure, notably causing a 27% decline in urban green space (UGS) resulting a net loss of 254 sq.km. Fragmentation analysis exhibited a trend of compact, infill development in urban regions, contrasting with outgrowth, which has influenced both the cluster size and quality of UGS over the decades. The multi-indices and biophysical characterization of UGS concluded a deteriorating trend in terms of quantity (− 27.9%) and quality as well with reference. However, the existing UGS are primarily scattered and having less dense. Spatial estimation of above ground biomass (AGB) of UGS using regression analysis of field-derived AGB and L-band SAR backscatter depicted a dominance of low AGB (< 30 t/ha−1) across KMC, while the certain zones with improved UGS exhibited moderate AGB levels (50–100 t/ha−1). The fuzzy AHP-based multi-criteria analysis of urban ecological quality exhibited severe ecological deterioration in the central urban areas, moderate to high in peri-urban regions, and comparatively improved ecological conditions in the peripheral rural parts of KMC. The study also identified major native tree species for plantation strategies comprising urban afforestation, rooftop gardens, and the development of green corridors in ecologically deficient hotspot zones to improve the ecological quality within the urban landscape. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Management of Aquatic Ecosystems and Aquatic Vegetation for Environmental Sustainability
(CRC Press, 2024) Shilky; Subhashree Patra; Purabi Saikia; Amit Kumar
Aquatic ecosystems are a critical element of the natural environment because they enable human activities like fishing, aquaculture, and recreation while also providing habitat for biodiversity and controlling water quality. Water pollution is a significant, deadly, and uncontrolled global issue due to a lack of knowledge, awareness, and the strict application of eco-friendly norms, legislation, and financial resources. Moreover, water scarcity affects ~40% of the global population as a result of climate change, aquatic weeds, algal blooms, heavy metal contamination, rapid urbanization, nutritional demand, and unrestrained use of natural resources. Aquatic ecosystems also provide opportunities to sustainably manage climate change, disaster risk, and pollution, if managed strategically. For instance, aquatic plants absorb pollutants from the water and clean it; these plants can be further utilized as a source of bioenergy resources. Furthermore, remote sensing tools used for monitoring, regulating the environmental repercussions, and comprehending the mechanisms controlling their spatial distribution, need real-time observations of toxins and marine pollutants over a variety of spatial scales. Therefore, a suitable legislative framework is a crucial tool for the sustainability of the aquatic ecosystems (freshwater, marine, and coastal) for achieving the SDG 14 targets. It will only be possible to achieve the objective of a sustainable economy by fostering a blue economy through the implementation of an integrated maritime policy. Therefore, establishing the proper legal framework is essential to carrying out the marine resources’ strategy efficiently. This chapter mainly focuses on challenges faced by aquatic ecosystems due to various natural and anthropogenic disturbances, conventional to advanced remote sensing tools to monitor it, and also suggests policy interventions and possible sustainable solutions to achieve UN-SDG 14. © 2025 selection and editorial matter, Prem Chandra Pandey, Prashant K. Srivastava, Sanjeev Kumar Srivastava; individual chapters, the contributors.
Mapping forest phenological shift in Nilgiri Biosphere Reserve, Western Ghats: Response to climate change
(Elsevier B.V., 2024) Bodi Surya Pratap Chandra Kishore; Amit Kumar; Purabi Saikia
In the present study, the spatiotemporal alterations in phenological metrics were analyzed in different forest types of Nilgiri Biosphere Reserve (NBR), Western Ghats, India with special reference to the impacts of changing climate on the forest phenology over two-phase periods (Phase 1: 2001–2010 and Phase 2: 2011–2020). Three phenological measures including the start/end/length of the season (SOS/EOS/LOS) were obtained using 16 days of MODIS Enhanced Vegetation Index (EVI) dataset over the two decades. The study exhibited a gradual delay in SOS during phase 1, and an advancing SOS during phase 2 in the tropical forests of NBR. Delayed EOS was observed in all forest types in NBR barring Moist Deciduous Forests (MDF) during phase 1, while opposite trend of advancing EOS was observed in deciduous forests (MDF and DDF: Dry Deciduous Forests), but delayed EOS was observed in evergreen forests (SEF: Semi Evergreen Forests and WEF: Wet Evergreen Forests) during phase 2. These variations in forest phenology are linked with an increase in annual mean temperature (0.01 °C year−1) along with a decrease in annual mean precipitation (3.97 mm year−1) during 1950–2018 as observed using IMD-based meteorological datasets. The results highlighted reduction in the total LOS with a delayed SOS and advanced EOS in NBR, which were prevalent during phase 1 conversely to phase 2 due to the varied intensity of changes in climatic conditions. However, disaggregating decade-long intervals into 5-year segments enables a finer resolution analysis of phenological trends. The study contributes to the development of long-term strategies for forest ecosystem restoration under the influence of global climate change by providing an insightful understanding of the non-systematic shifts in forest phenology attributed by rising warming impacts and erratic precipitation patterns. © 2024 Elsevier B.V.