Tracing the land use specific impacts on groundwater quality: a chemometric, information entropy WQI and health risk assessment study.

Understanding the nexus of land use and water quality can potentially underline the influences within the groundwater management. The study envisages land use-specific qualitative assessment of the groundwater resources in Ghaziabad district, in western Uttar Pradesh, India. For encountering the relative impacts of land use on the groundwater quality, chemometric analysis has been employed to apportion the pollution sources. The integration of quality parameters, in the information entropy index modeling, has segregated the quality classes and visualized the seasonal suitability trends as per potability standards along with non-carcinogenic health hazard risk assessment (HHRA). The qualitative assessment of the groundwater resources, along with spatial distribution, has deciphered a polluting impact, specifically in western and south western parts of district, and observed the linkages with direct and indirect discharges/seepages from densely populated residential and industrial land use types localized in urbanized areas. Statistically significant annual and seasonal variations have been found exclusively for EC, Mg2+, F-, Cd, Cr(total), Ni, and Pb which inferred variable concentrations, whereas land use types showed a non-significant variation within groundwater quality. Chemometric-based source apportioning and hierarchical cluster analysis (HCA) have derived salinization and enrichment of dissolved salts, arising from mixed sources and contributes to metal pollution, i.e., mainly from anthropogenic sources. Information EWQI derived poor to extremely poor category represented degraded potability specifically for fewer sites located within western and southern parts on the Yamuna-Hindon flood plains for limited sites of residential, industrial, and agricultural in an urbanized region. However, majority of the samples fall under excellent to good groundwater quality, recommendable in the north and north-eastern (peri-urban) regions. Non-carcinogenic HHRA has shown that majority of the samples categorized under unsafe value for hazard index (HI > 1), for females and children and thus, presumed probable health hazard risk from metal groundwater pollution in south-western part, eastern, and northern regions.

Evaluation of water hyacinth utility through geospatial mapping and in situ biomass estimation approach: a case study of Deepor beel (wetland), Assam, India.

As an invasive species, water hyacinths (Eichhornia crassipes) are known to progressively proliferate and cause the ecological invasions of the aquatic environment. The incursions of the water hyacinths not only cause the disappearance of native species but gradually degrade the natural habitats of freshwater regimes. The control and management of these species are laborious task; however, transforming weed into wealth can substantially serve a sustainable approach to reduce the efforts. Therefore, the present study intends to utilize the application of geospatial techniques for mapping the water hyacinths growth in the Deepor beel (wetland) of Assam, India. Sentinel based image analysis has shown that pre-monsoon seasons has encountered massive productivity and area coverage of water hyacinth, whereas in post-monsoon seasons, productivity of water hyacinths reduces to half. Furthermore, in situ biomass estimation of the water hyacinth samples, same around the productive season has been collected and was analyzed as 6 kg (green biomass) and 1 kg (dry biomass after sun-dried). Finally, this hybrid approach evaluated the production and revenue generation from Moorhen yoga mat (handicraft item) made from the dried water hyacinths. After assuming the actual availability of 50% of total mass yield of water hyacinths, around ~ 0.8 million (8.8 lakhs) yoga mats can be commercially produced within the most productive seasons. The revenue generation from the yoga mat in the domestic and international markets evaluated around US $12.79 million (Rs. 105.85 crore) and US $15.99 million (Rs. 132.31 crore), respectively, from a single productive season. Thus, applicative intent of this study can boost potential market in Assam, renovate the weed waste of water hyacinth into wealth generation, and sustainably support the livelihoods of the local communities.

Land use dynamics and its influences on groundwater depth levels in South region of National Capital Territory (NCT) of Delhi, India.

The present study envisions the influences of land use dynamics on the spatial trend of groundwater depth levels over a period of two decades in the south region of NCT Delhi, India. The findings have inferred that among five major LULC categories, built-up has shown a sprawling trend (+2.17 km2/year) from the north, northeastern, and central portions to the confined patches observed in the south and southwest fringes of South Delhi from 2001 to 2021. Likewise, vegetation class has also witnessed significant increment (+1.91 km2/year) to the peripheral boundary, i.e., southern, southwest/eastern fringes, and central portions under recent initiatives of city forests, plantation drives, and urban green spaces programs. On the contrary, a negative rate of change has been observed in fallow land (-2.78 km2/year), agriculture (-1.22 km2/year), and water bodies (-0.07 km2/year). LULC transition matrix has also showed prominent conversion of fallow land into vegetation and built-up class, and change of vegetation into built-up, and fallow land category. Subsequently, corresponding LULC maps have been superimposed with long-term trends of groundwater depth levels (as spatial contours). For entire South Delhi region, depth to water levels ranged from 2.02 to 66.45 meters below ground level (mbgl) where shallower depths followed a negative trend and remain persistent throughout the time period in north and northeastern fringes. Higher fluctuations in groundwater depletion with positive trends directly get influenced with allied land use transitions such as a steady increase in built-up area and steeper depth levels (> 40 mbgl) as observed in central, southwestern, and southern parts. Moreover, buffer peripheries in the proximity of groundwater monitoring stations viz., Hauz Khas, Pushp Vihar, Jamali, Gadaipur, and Bhatti Kalan have observed deeper groundwater levels allied to built-up expansion. Thus, groundwater depletion trends can be ascribed to the incessant conversion of recharging areas into impervious zones along with uneven distribution of groundwater usage and supply. Conversely, expanding vegetative land has also shown improved groundwater depth levels. Therefore, land use influences must be managed in the long run for ensuring sustainable management of groundwater resources.

Interplay of moss cover and seasonal variation regulate soil physicochemical properties and net nitrogen mineralization rates in Central Himalayas, India.

Mosses (Class- Bryopsida) are vital to ecosystem dynamics in numerous biomes, although their effects on soil processes are poorly understood. The interplay of moss cover and seasonal variations in soil processes is still unclear in the Indian Central Himalayas. Therefore, we examined the seasonal variations in net nitrogen (N) mineralization rates and several soil properties under two ground covers (with and without moss cover). We used the ex-situ incubation technique to determine N mineralization rates (Rmin) and standard methodology for soil physical and chemical analysis. During the rainy season, the physical properties of the soil and its nutrients, apart from phosphorus, were higher under moss cover. The winter season, however, showed a different pattern, with soil properties exhibiting higher values in soils without moss cover. Ammonium concentrations were higher under moss cover, while nitrate concentrations were higher in soil without moss cover during rainy and winter seasons. The Rmin rates were higher in soil under moss cover, indicating that moss cover promotes N transformation. In contrast, Rmin rates were negative in soil without moss cover, indicating that N immobilization was dominant in N transformation under this ground cover during the rainy season. Our research shows that mosses positively impact the nutrient status and N mineralization rates in various temperate forest types. The seasonal patterns of soil properties are strongly influenced by soil temperature, moisture, and organic carbon. Therefore, we advocate the conservation of mosses and their integration into forest management plans for better ecosystem processes and services in the ecologically fragile Himalayas.

The plight of Najafgarh drain in NCT of Delhi, India: assessment of the sources, statistical water quality evaluation, and fate of water pollutants.

The Najafgarh drain is the first major drain that joins the Yamuna River at Wazirabad in Delhi, India, and is known to contribute to the maximum pollution load to this river. The drain is originally an extension of the Sahibi River and was intentionally constructed as a canal to carry stormwater, but presently, it is carrying more of sewage, agricultural, and industrial effluents received through various small and large secondary drains. The present study has analyzed the water quality status of this interconnected system, i.e., the Najafgarh drain, its associated secondary drains, and the Yamuna River for physicochemical parameters (n = 16), microbiological parameter (n = 1), and heavy metal concentrations (n = 8). The analysis of the surface water samples collected during pre- and post-monsoon seasons showed that secondary drain discharges significantly impacted the water quality of the Najafgarh drain, which in turn affected the Yamuna River. Out of the eight selected secondary drains for this study, the Goyla dairy outlet came out as the most polluted site in terms of organic pollutants while the Basaidarapur drain was loaded with heavy metal contaminants. Statistical tools comprising hierarchical cluster analysis (HCA), Pearson's correlation, and principal component analysis (PCA) were further implemented on the water quality dataset for a better understanding of the possible sources of contamination for organic and inorganic pollutants in the selected sampling sites. The present study, thus, might help in providing key highlights to the policymakers for effective regulation and management of the point source discharges in Najafgarh drain, which will ultimately restrict its pollution loadings in Yamuna River, Delhi, and also help in the restoration of this important water body.

Assessing the effectiveness of community managed forests for plant diversity conservation in Meghalaya, Northeast India.

In the state Meghalaya, northeast India, >80% of the forest lands are owned by local communities and managed by traditional institutions. These forests are under severe threats due to a number of human disturbances. The present study was conducted to assess the plant diversity and identify the community forests for priority conservation in Khasi Hills of Meghalaya. Floristic explorations carried out in the 87 forests reveals the presence of 1300 plant species of which 400 are either rare, endemic or threatened. Of the different forest categories, reserve forests had the highest number of species (1190), followed by sacred forests (987 species) and village forests (786 species). Majority of the forests (56) had high-species richness, irreplaceability level (42 forests) and vulnerability level (54). In terms of area, 13.8% (1666.8 ha) fall under low risk while 1855 ha under high risk zone. High risk zone was mostly represented by village forests. An area of 7661.56 ha of community forests falls under high priority category and hence calls for immediate conservation actions. The conservation priority map generated in the present study will help to concentrate the protection strategy to the demarcated and adjoining areas and help conservationists and planners to evolve effective strategies for conservation of the community forests.

Spatio-temporal assessment on land use and land cover (LULC) and forest fragmentation in shifting agroecosystem landscape in Ukhrul district of Manipur, Northeast India.

The information on land use and land cover (LULC) plays a critical role in understanding the interactions between human activities and the natural environment. The changes in LULC have a significant impact on the ecological integrity of forests, biodiversity, and natural resources, which in turn trigger global environmental change. Forest fragmentation is an important conservation challenge that includes interdependent forest loss components and spatial shift patterns. Over the years, Northeast India has experienced major changes in LULC and forest fragmentation. There are limited information and data regarding the change in LULC patterns and causes of forest fragmentation. The present study was carried out with an attempt to analyze the change in LULC and forest fragmentation using satellite data of three different time series: 1991, 2005, and 2020 for Ukhrul district, Manipur, Northeast India. Different LULC classes were classified using the supervised method, viz., maximum likelihood algorithm in ERDAS Imagine 2014 and generated thematic maps in ArcGIS 10.4 software. Considering the classified forest class, fragmentation in the forest area was grouped into different categories of fragmentation using the Landscape Fragmentation Tool (LFT v 2.0). The distribution of the perforated category has tremendously increased in 2020 from 1991. The outcome of the present study will help to understand the inherent forest vulnerability and to adopt sustainable management strategies for forest and agriculture ecosystems in the hill landscape.

Taxonomy, population status and ecology of Indian desert monitor lizard Varanus griseus koniecznyi Mertens 1954 in the Thar desert of Rajasthan.

Among monitor lizards of the family Varanidae, Indian desert monitor lizard Varanus griseus koniecznyi Mertens 1954 is one of the lesser-known species globally and due to lack of data on this species it is so far not evaluated by IUCN and excluded from the latest assessment of monitor lizards of Southeast Asia and Indo-Australian Archipelago. The present study was undertaken from January 2013 to June 2017 to fill this gap during which taxonomic evaluation along with an assessment of population and ecology of this species was carried out in the Thar desert of Rajasthan (TDR). The study brought into knowledge many morphological variations along with intraspecific variations of scale microstructure of this lizard. The population density was found to be highest in the Jaisalmer (0.102/ha) district of western Rajasthan, followed by Bikaner (0.08/ha) and Sikar (0.077/ha) districts. The overall population was quite low (0.068/ha) in the area. The study further revealed the species is habitat specialist and lives in a narrow range of habitats and microhabitats, and hence, the species may not adapt to the rapidly changing environment in the TDR. Their activity was found to be highest between 9ndash;12 hrs followed by 12-15 hrs and foraging was found to be their predominant activity followed by resting and feeding. In the absence of any detailed study on this species, the study points towards immediate conservation efforts for the species in its current distribution. Baseline data generated through this study will no doubt help to safeguard the species in the TDR and further research on this species in the future.

Microplastic pollution in aquatic environments with special emphasis on riverine systems: Current understanding and way forward.

Microplastics (MPs) are emerging as a severe threat in our environment. Their diverse existence in marine environments is being researched globally and thus a widely known fact; however, their presence in the freshwater counterpart has gained attention lately only. Riverine systems, the most critical freshwater resources serve as an essential link between terrestrial and marine environments and their contamination with MPs is going to create severe environmental issues. Because of their small size and unique morphology, these polymers can exhibit variable toxicity to the interacting biota and alter their habitat properties; thus, causing serious impacts on the environment and health of living beings, including humans. These microplastics can also interact with pollutants like heavy metals and organic pollutants, which further augment their harming potential. Inefficient and poor plastic waste disposal practices play an important role in the generation of microplastic pollutants. In the present COVID 19 pandemics, the excessive use of plastic to contain the spread of infection has further added the plastic load in the environment which will eventually lead to the generation of microplastic particles. Also, a significant amount of microplastic pollutants in riverine systems are delivered through wastewater treatment plant effluents. These trade-offs create a distress situation in the environment. The present study connects these key issues for a better understanding of the diverse existence of microplastic pollutants, their sources, and fate, with a special emphasis on riverine systems. A critical appraisal of the knowledge gaps and proposal of suitable solutions through this review might open up avenues for further research and effective management of the microplastics in aquatic environments.

Impact of heavy metals on water quality and indigenous Bacillus spp. prevalent in rat-hole coal mines.

The present study reports pollution evaluation indices employed to assess the intensity of metal pollution in water systems affected by acid mine drainage from rat-hole coal mines prevalent in North-east India. The concentration of seven eco-toxic metals was evaluated from coal mine waters which showed concentration order of Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Chromium (Cr) > Lead (Pb) > Copper (Cu) > Cadmium (Cd). The water samples were acidic with mean pH 2.67 and burdened with dissolved solids (924.8 mg/L). The heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) displayed high and medium range of pollution level in majority of the water samples. Statistical correlation suggested strong positive correlation between metals such as Cr with Mn (r = 0.780), Mn with Fe (r = 0.576), Cr with Fe (r = 0.680), Pb with Mn (r = 0.579) and Cr with Pb (r = 0.606), indicating Mn, Pb, Fe and Cr to be major metal contaminants; an unequivocal affirmation of degradation in water quality. The sampled waters had lower heavy metal concentration during monsoon and post-monsoon seasons. The commonly occurring bacterial species Bacillus pseudomycoides and Bacillus siamensis were chosen to understand their behavioral responses toward metal contamination. Findings demonstrated that Bacillus spp. from control environment had low tolerance to metals stress as evident from their MTC, MIC and growth curve studies. The survival of the native isolates across varying pH, salinity and temperature in the coal mine areas suggest these isolates as promising candidates for reclamation of rat-hole coal mining sites.