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    Differential responses of hydrochemical factors and LULC changes on the spatial and temporal hydrogeochemistry of the eco-sensitive Baraila wetland, Bihar, India
    (Springer Science and Business Media Deutschland GmbH, 2023) Aslam, Alvia; Ahmad, Tauseef; Ranjan, Rajesh Kumar
    Freshwater scarcity, deterioration and associated water management remain to be one of the most challenging aspects of high-population density economies especially in subtropical/tropical regions. The present research deals with hydrogeochemical analysis of the eco-sensitive Baraila wetland and possible sources of anthropogenic pollution. The hydrochemical characterization was performed in GIS environment, considering meteorologically induced parameters and spatial variability. Temporal variations were assessed through different seasons, namely pre-monsoon, monsoon and post-monsoon with the help of multivariate statistics. The changes in water depth across the seasons showed significant hydrochemical variations in the vertical profile of the wetland apart from thermal demarcation. Seasonal variations in the hydrogeochemistry were induced by multiple physicochemical parameters, geochemical processes, geomorphology of the surrounding area and land use and land cover (LULC) changes. The pre-post flooding changes revealed that aquatic vegetation was increased by 15.36% whereas a major decrease in water bodies (− 73.2%) occurred. Dissolved oxygen (DO), pH, temperature and carbonates are fundamental towards establishing wetland’s water chemistry. The water type is primarily of Ca-HCO3 type, mostly derived from rock-water interactions and cation exchange processes. Irrigational quality of water was assessed through multiple indices (sodium adsorption ratio (SAR), %Na, residual sodium carbonate (RSC), magnesium hazard (MH) and total hardness (TH)) and plots. The heavy aquatic vegetation abundance and eutrophication because of agricultural run-off is currently the major issue with the Baraila wetland and may be playing a simultaneous role in regulating the water chemistry to a large extent apart from other geochemical processes. The hydrogeochemical interactions between sediment and overlying water have created distinct effects on biota and land use/land cover changes. Their role in the landscape is prominent in this respect and may be utilized for environmental management, eco-tourism and employment boost. Serious lack of hydrogeochemical studies in this important floodplain wetland and its rapid deterioration deems it necessary to focus on the comprehensive research and wetland management options for its conservation and sustainable usage in future.
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    Land Use and Land Cover Changes in Kabul, Afghanistan Focusing on the Drivers Impacting Urban Dynamics during Five Decades 1973-2020
    (Mdpi, 2023) Hekmat, Hayatullah; Ahmad, Tauseef; Singh, Suraj Kumar; Kanga, Shruti; Meraj, Gowhar; Kumar, Pankaj
    This study delves into the patterns of urban expansion in Kabul, using Landsat and Sentinel satellite imagery as primary tools for analysis. We classified land use and land cover (LULC) into five distinct categories: water bodies, vegetation, barren land, barren rocky terrain, and buildings. The necessary data processing and analysis was conducted using ERDAS Imagine v.2015 and ArcGIS 10.8 software. Our main objective was to scrutinize changes in LULC across five discrete decades. Additionally, we traced the long-term evolution of built-up areas in Kabul from 1973 to 2020. The classified satellite images revealed significant changes across all categories. For instance, the area of built-up land reduced from 29.91% in 2013 to 23.84% in 2020, while barren land saw a decrease from 33.3% to 28.4% over the same period. Conversely, the proportion of barren rocky terrain exhibited an increase from 22.89% in 2013 to 29.97% in 2020. Minor yet notable shifts were observed in the categories of water bodies and vegetated land use. The percentage of water bodies shrank from 2.51% in 2003 to 1.30% in 2013, and the extent of vegetated land use showed a decline from 13.61% in 2003 to 12.6% in 2013. Our study unveiled evolving land use patterns over time, with specific periods recording an increase in barren land and a slight rise in vegetated areas. These findings underscored the dynamic transformation of Kabul's urban landscape over the years, with significant implications for urban planning and sustainability.
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    Unveiling Nature's Resilience: Exploring Vegetation Dynamics during the COVID-19 Era in Jharkhand, India, with the Google Earth Engine
    (Mdpi, 2023) Ahmad, Tauseef; Gupta, Saurabh Kumar; Singh, Suraj Kumar; Meraj, Gowhar; Kumar, Pankaj; Kanga, Shruti
    The Severe Acute Respiratory Syndrome Coronavirus Disease 2019 (COVID-19) pandemic has presented unprecedented challenges to global health and economic stability. Intriguingly, the necessary lockdown measures, while disruptive to human society, inadvertently led to environmental rejuvenation, particularly noticeable in decreased air pollution and improved vegetation health. This study investigates the lockdown's impact on vegetation health in Jharkhand, India, employing the Google Earth Engine for cloud-based data analysis. MODIS-NDVI data were analyzed using spatio-temporal NDVI analyses and time-series models. These analyses revealed a notable increase in maximum vegetation greenery of 19% from April 2019 to 2020, with subsequent increases of 13% and 3% observed in March and May of the same year, respectively. A longer-term analysis from 2000 to 2020 displayed an overall 16.7% rise in vegetation greenness. While the maximum value remained relatively constant, it demonstrated a slight increment during the dry season. The Landsat data Mann-Kendall trend test reinforced these findings, displaying a significant shift from a negative NDVI trend (1984-2019) to a positive 17.7% trend (1984-2021) in Jharkhand's north-west region. The precipitation (using NASA power and Merra2 data) and NDVI correlation were also studied during the pre- and lockdown periods. Maximum precipitation (350-400 mm) was observed in June, while July typically experienced around 300 mm precipitation, covering nearly 85% of Jharkhand. Interestingly, August 2020 saw up to 550 mm precipitation, primarily in Jharkhand's southern region, compared to 400 mm in the same month in 2019. Peak changes in NDVI value during this period ranged between 0.6-0.76 and 0.76-1, observed throughout the state. Although the decrease in air pollution led to improved vegetation health, these benefits began to diminish post-lockdown. This observation underscores the need for immediate attention and intervention from scientists and researchers. Understanding lockdown-induced environmental changes and their impact on vegetation health can facilitate the development of proactive environmental management strategies, paving the way towards a sustainable and resilient future.