Ganga River Basin Research Articles

Matrilineal phylogeny and habitat suitability of the endangered spotted pond turtle (Geoclemys hamiltonii; Testudines: Geoemydidae): a two-dimensional approach to forecasting future conservation consequences.

The spotted pond turtle (Geoclemys hamiltonii) is a threatened and less explored species endemic to Bangladesh, India, Nepal, and Pakistan. To infer structural variation and matrilineal phylogenetic interpretation, the present research decoded the mitogenome of G. hamiltonii (16,509 bp) using next-generation sequencing technology. The mitogenome comprises 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one AT-rich control region (CR) with similar strand symmetry in vertebrates. The ATG was identified as a start codon in most of the PCGs except Cytochrome oxidase subunit 1 (cox1), which started with the GTG codon. The non-coding CR of G. hamiltonii was determined to have a unique structure and variation in different domains and stem-loop secondary structure as compared with other Batagurinae species. The PCGs-based Bayesian phylogeny inferred strong monophyletic support for all Batagurinae species and confirmed the sister relationship of G. hamiltonii with Pangshura and Batagur taxa. We recommend generating more mitogenomic data for other Batagurinae species to confirm their population structure and evolutionary relationships. In addition, the present study aims to infer the habitat suitability and habitat quality of G. hamiltonii in its global distribution, both in the present and future climatic scenarios. We identify that only 58,542 km2 (7.16%) of the total range extent (817,341 km2) is suitable for this species, along with the fragmented habitats in both the eastern and western ranges. Comparative habitat quality assessment suggests the level of patch shape in the western range is higher (71.3%) compared to the eastern range. Our results suggest a massive decline of approximately 65.73% to 70.31% and 70.53% to 75.30% under ssp245 and ssp585 future scenarios, respectively, for the years between 2021-2040 and 2061-2080 compared with the current distribution. The present study indicates that proper conservation management requires greater attention to the causes and solutions to the fragmented distribution and safeguarding of this endangered species in the Indus, Ganges, and Brahmaputra (IGB) river basins.

MONITORING GROUNDWATER STORAGE BASINS AND HYDROLOGICAL CHANGES USING THE GRACE SATELLITE AND SENTINEL-1 FOR THE GANGA RIVER BASIN

Abstract. Groundwater depletion-related subsidence is a significant issue in many parts of the world. It can permanently reduce the amount of groundwater stored in an aquifer and even cause structural damage to the Earth’s surface. The Ganga Basin in the northwestern region of India is no exception, with around a meter of subsidence occurring between 2018 and 2023. However, understanding the connection between variations in groundwater quantities and ground deformation has been challenging. We used surface displacement measurements from InSAR and gravimetric terrestrial water storage estimates from the GRACE satellite pair to characterize the hydrological dynamics within the Ganga Basin. Sentinel-1 was used to map the entire Ganga River basin in the inundated zone. The InSAR time series shows coherent short-term changes that coincide with hydrological features when the long-term aquifer compaction is removed. For instance, an uplift is seen at the confluence of multiple rivers and streams that drain into the southeastern margin of the basin in the winters of 2018–2019 and 2021–2022. Imaging the monthly spatial variations in water volumes is based on these data and calculations of mass changes from the orbiting of Sentinel-1 and GRACE satellites. We even employ machine learning techniques as evaluative methods to make it simple to combine InSAR quickly and convincingly with gravimetric datasets, which will help advance global efforts to understand better and manage groundwater resources.

Groundwater levels estimation from GRACE/GRACE-FO and hydro-meteorological data using deep learning in Ganga River basin, India

Groundwater levels estimation from GRACE/GRACE-FO and hydro-meteorological data using deep learning in Ganga River basin, India

Record of zipper loach Paracanthocobitis mackenziei (Chaudhuri, 1910), an indigenous ornamental fish from West Bengal, India

Paracanthocobitis mackenziei (Chaudhuri, 1910) is an ornamental fish belonging to the family Nemachilidae, mainly reported from several localities in the Ganges River basin of Uttar Pradesh and Bihar in Northern India. During a study on indigenous ornamental fish diversity in Paschim Medinipur district, P. mackenziei has been recorded for the first-time from Kangsabati River basin. The specimens have been identified based on morphometric and meristematic craracteristics. This report is the extension of the distribution of the species up to the South-Western part of West Bengal.

Projected climate extremes over agro-climatic zones of Ganga River Basin under 1.5, 2, and 3° global warming levels.

Recurring floods, droughts, heatwaves, and other hydro-meteorological extreme events are likely to be increased under the climate change scenarios. The increased risk of these extreme events might have more exposure to the population; thus, it is important to discuss such extreme events and their projected behavior under a changing climate scenario. In the present study, we have computed the extreme precipitation and temperature indices over the 10 agro-climatic zones falling under the Ganga River Basin (GRB)utilizing a high-resolution daily gridded temperature and precipitation multi-model ensembled CMIP6 dataset (0.25° × 0.25°) under global warming levels of 1.5°C, 2°C, and 3°C. We found that the annual daily minimum temperature (TNN) showed a higher rise of about 67% than the maximum temperature (TXX) of 48% in GRB. The basin also experiences a greater increase in the frequency of warm nights (TN90P) of about 67.71% compared to warm days (TX90P) of 29.1% for the 3°C global warming level. Along with extreme indices, the population exposed due to the impact of the extreme maximum temperature has also been analyzed for progressive warming levels. Population exposure to extreme temperature event (TXX) has been analyzed with 20-year return period using GEV distribution method. The study concludes that the exposed population to extreme temperature event experienced an increase from 46.99 to 52.16% for the whole Ganga Basin. Consecutive dry days (CDD) and consecutive wet days (CWD) both show a significant increasing trend, but CWD has a significant increase in the majority of the zones, while CDD shows a significant decreasing trend for some of the zones for three warming levels periods. Extreme climate indices help to understand the frequency and intensity of extreme weather events such as heavy rainfall, droughts, and heatwaves to develop early warning systems and adaptation strategies to mitigate such events.

Ramifications of groundwater model in WRF/Noah‐MP coupled system: Effects on soil‐moisture and regional climate simulation

AbstractSoil moisture is a key variable that contributes for flux partitioning into sensible and latent heat components. There is a pressing need to study the impacts of shallow groundwater table dynamics on antecedent soil moisture and corresponding feedbacks to atmosphere. In this study, we evaluate WRF‐NoahMP simulated soil moisture using two experimental configurations: one with the default, free drainage approach (CTL) and with Miguez‐Macho groundwater scheme (GW). Results are presented for the study conducted over Ganga River basin, India between the years 2008 and 2014 for all the three seasons (pre‐monsoon, monsoon, post‐monsoon). It was observed that the GW model runs, improve soil moisture in topmost and bottom‐most layers. We discovered that the simulations improved temporal negative bias of seasonal accumulation during monsoon by around 91 mm. In addition, the average negative bias in latent heat flux improved by around 28 W/m2. Compared to CTL, GW was found to contribute additional atmospheric moisture content ranging between 3% and 5%. Comparison with in‐situ ground water showed that model overestimates the ground water table depth. This can be attributed to the ability of the model to only simulate natural occurring variabilities and lack of inclusion of anthropogenic factors such as ground water pumping in the model. The groundwater trend in Ganga is declining at alarming rate. In addition, if over exploitation of groundwater is not monitored properly, water and food scarcity is an imminent threat to the country's economy. To the best of authors knowledge, this is the first study of its kind to be implemented over Ganga basin, which evaluates the role of shallow ground water table on regional climate using coupled atmosphere‐land surface‐groundwater model. In summary, we highlight that the groundwater component along with WRF‐NoahMP coupled model improves soil moisture and precipitation representation over the Ganga basin.

Wastewater Reuse - A Prospective towards Efficient Reuse of Treated Wastewater from Sugar Industries of River Ganga Basin for Irrigation

Wastewater Reuse - A Prospective towards Efficient Reuse of Treated Wastewater from Sugar Industries of River Ganga Basin for Irrigation

Securing Zero Black Liquor Discharge in Pulp and Paper Industries of River Ganga Basin through Participatory Approach

Securing Zero Black Liquor Discharge in Pulp and Paper Industries of River Ganga Basin through Participatory Approach

Comprehensive Evaluation of High-Resolution Satellite Precipitation Products over the Qinghai–Tibetan Plateau Using the New Ground Observation Network

Satellite precipitation products (SPPs) have been widely evaluated at regional scales. However, there have been few quantitative comprehensive evaluations of SPPs using multiple indices. Ten high-resolution SPPs were quantitatively and comprehensively evaluated from precipitation occurrence and series indices using an improved rank score (RS) method in the data-scarce Qinghai–Tibetan Plateau (QTP). The new observation network, along with a number of national basic stations, was applied for SPP evaluation to obtain more reliable results. The results showed that the GPM and MSWEP showed the strongest overall performance, with an RS value of 0.75. CHIRPS and GPM had the strongest performance at measuring precipitation occurrence (RS = 0.92) and series (RS = 0.75), respectively. The optimal SPPs varied in evaluation indices, but also concentrated in the MSWEP, GPM, and CHIRPS. The bias of SPPs was markedly in the QTP, with relative error generally between −80% and 80%. In general, most SPPs showed the ability to detect precipitation occurrence. However, the SPPs showed relatively weak performance at measuring precipitation series. The mean Kling–Gupta efficiency of all stations was <0.50 for each SPP. The SPPs showed better performance in monsoon-affected regions, which mainly include the Yangtze, Yellow, Nu–Salween, Lancang–Mekong, Yarlung Zangbo–Bramaputra, and Ganges river basins. Performance was relatively poor in the westerly circulation areas, which mainly include the Tarim, Indus, and QTP inland river basins. The performance of SPPs showed a seasonal pattern during the year for most occurrence indices. The performance of SPPs in different periods was opposite in different indices. Therefore, multiple indices representing different characteristics are recommended for the evaluation of SPPs to obtain a comprehensive evaluation result. Overall, SPP measurement over the QTP needs further improvement, especially with regard to measuring precipitation series. The proposed improved RS method can also potentially be applied for comprehensive evaluation of other products and models.

Modelling the relative risk of plastic pollution to wildlife when data are scarce: an applied approach in the Mekong and Ganges river basins

Plastic pollution of aquatic ecosystems is a growing environmental problem. Most plastic pollution originates from land-based sources and is transported via rivers, where plastic densities can exceed those at sea. Rivers in southeast Asia are regularly identified among those transporting the greatest plastic loads globally, yet are among the least studied major river systems. This is particularly concerning since they provide habitat for commercially, culturally and ecologically important species. We present a four-step risk framework to assess the relative risk to wildlife at different sections of a river, particularly where data may be sparse. We apply this method to a case study in the Ganges and Mekong rivers. The first step is to estimate litter density and abandoned fishing gear (ALDFG) to determine the relative level of pressure from ingestion or entanglement. Step two uses a risk assessment to determine the likelihood of a species interacting with a given item, and the further likelihood of a negative outcome of that encounter. Step three determines the overlap of the habitat of the species with the litter present in the environment, and the final step integrates all of these factors to present an overall relative risk to migratory species within each watershed. In the Ganges and Mekong rivers, entanglement represents the highest risk to species. The methods presented here estimate the relative risk to vertebrate fauna from litter interactions in rivers where empirical data are not available, aiming to determine (i) where in each river do we expect to find the most plastic and ALDFG and (ii) whether species suspected to be threatened by plastic pollution overlap with these predicted high-risk regions. This approach will aid decision-makers to make informed precautionary assessments bridging data gaps about relative plastic loads and associated risks in aquatic systems, until empirical data becomes available.

Assessing the fluoride toxicity, and the source contributors to the major ionic constituents in the groundwater aquifer of Middle Ganga River Basin, Rohtas, India

Assessing the fluoride toxicity, and the source contributors to the major ionic constituents in the groundwater aquifer of Middle Ganga River Basin, Rohtas, India

Basin-Scale Geochemical Assessment of Water Quality in the Ganges River during the Dry Season

Identification of sources and transport pathways of heavy metals and major ions is crucial for effective water quality monitoring, particularly in large river systems. The Ganges river basin, the largest and the most populous river basin in India, remains poorly studied in this regard. We conducted a basin-level analysis of major ions, heavy metals, and stable isotopes of nitrate in the Ganges during the pre-monsoon season to constrain the sources and quantify the inorganic chemical composition of the river during its lean flow. Bedrock weathering, anthropogenic interferences, water contribution through tributaries, and surface water-groundwater interaction were identified as the major driver of metal and ion variability in the river. Heavy metals showed the highest concentrations in the upper section of the river, whereas ionic loads were the most variable in the middle. We find a significant impact of tributaries on the metal and ion concentrations of the Ganges in its lower reaches. Isotopic analysis of dissolved nitrate suggested synthetic fertilizers and industrial wastes as the main sources. We find that the otherwise clean waters of the Ganges can show high ionic/metallic concentrations at isolated stretches (As: up to 36 µg/L), suggesting frequent monitoring in the source region to maintain water quality. Except for water collected from the Yamuna and Kannauj in the middle stretch and the Alaknanda and Rishikesh in the upper stretch, the WQI showed acceptable water quality for the sampled stations. These findings provide an insight into the modifications of dissolved inorganic chemical loads and their sources in different sections of the basin, needed for mitigating site-specific pollution in the river, and a roadmap for evaluating chemical loads in other rivers of the world.

Nepal’s Water Diplomacy: Relationship with her Neighbours

Water is the most important natural resource of Nepal. Its importance and demand have been increasing over time, not only in Nepal but also in all of the South Asia region. The Ganges River Basin is the most populous region in the world. People living in and around the Basin rely mainly on the Ganges River to meet their growing water requirements. However, the Ganges River is mostly fed by the rivers that originate in Nepal and Tibet Autonomous Region of China. This paper explores the possibility of Nepal using water as a driver for the development of the region as part of its regional diplomacy.

A multivariate statistical approach to evaluate the hydro-geochemistry of groundwater quality in the middle Ganga river basin, Patna, India

A multivariate statistical approach to evaluate the hydro-geochemistry of groundwater quality in the middle Ganga river basin, Patna, India

Glacier changes and their impacts on the melt runoff in high and moderate elevation ranges of Himalayan Upper Ganges Basin

AbstractThe rise in temperatures over the Himalayan regions due to climate change have shown profound effects on the seasonality and long‐term availability of snow melt runoff and glacier melt runoff. As per the sixth assessment report by the Intergovernmental Panel on Climate Change, the Himalayan glaciers are retreating and the fraction of precipitation falling as snow is altering. This study analyses the effect of snow‐glacier changes on the melt runoff (1986–2020) over the Upper Ganga river basin (up to Rishikesh) using a fully distributed model namely, Spatial Process in Hydrology (SPHY), which governs by Temperature Index Model approach with varying degree‐day factors. This study performs the two‐step calibration approach for model parameterization and to evaluate the snow and glacier melt runoff utilizing the observed discharge and real time satellite datasets. The SPHY derived snow cover was compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) derived snow covers. Results show that the SPHY modelled fractional snow covers found comparable to MODIS derived snow covers (~70%–90% correlation). The R2 based comparison of SPHY modelled runoff (Q) and observed Q at two gauges namely, Maneri (~0.85) and Rishikesh (~0.80) found reasonable. For the assessment of glacier changes and corresponding melt runoff, temporal glacier maps (i.e., for years 1990, 2000, 2010, 2020) were prepared utilizing the Landsat imageries. Results showed a noticeable reduction in the glacier areas (~5% mass reduction in 30 years) and an increase in glacier melt runoff at different stations (e.g., at Bhojwasa ~3%–4% and at Rishikesh ~1%–2%). Similarly, a decrease in snow melt runoff (~3%–4%) and an increase in rainfall runoff (~3%) were computed. A month wise percent of change analysis has shown significant fluctuations in the magnitude and seasonality of all runoff components (i.e., snow Q, glacier Q, base Q and rainfall induced Q) in the Himalayan Upper Ganga basin.

Environmental Threats to South Asia’s Basins (Indus and Ganga); Treaties Analysis

The article aims to provide insights into the effectiveness of international water treaties in addressing environmental challenges in river basins. The Ganga and Indus River basins, encompassing a vast expanse of 2.20 million square kilometers, serve as the lifeblood for roughly one billion inhabitants of the South Asian region. However, the escalating challenges of water scarcity, climate change, over-extraction, pollution, and reduced flow that stem from burgeoning population growth, urbanization, industrialization, and agricultural activities, have critically endangered the water quality and quantity of these basins. The Ganga and Indus Water Treaties were created to promote collaboration and address water-related environmental issues. However, their limitations in addressing these threats make it necessary to review their effectiveness and examine their gaps and inadequacies. The study examines treaties related to the Indus and Ganga River basins regarding environmental threats, identifying gaps that need attention. A comparative analysis with the UN Watercourse Convention will be conducted to assess their effectiveness and adherence to global standards. Key Words: Environmental threats, IWT, Ganga treaty, UNWC

Identification of Sources and Mobilization of Trace Elements in Shallow Groundwater of the Upper Ganges River Basin

The concentration of trace metals in groundwater is still not within the usual standards established by the national and international monitoring authorities. This study aims to evaluate the sources and distribution of trace metals in the shallow aquifer water of the Ganges River basin in the Bangladesh area. A total of 40 groundwater samples were collected and investigated for 11 trace elements and some selected water parameters followed by sophisticated methods. The results presented that three metals, viz. Fe, Mn, and Pb crossed the limit of WHO standard in most of the samples (70-100%), representing severe human health hazards. Besides, the samples are slightly acidic to basic and highly mineralized by divalent cations and bicarbonate because total hardness was found very high. To assess factors affecting the trace metal loads in groundwater samples and determine their possible sources and mobility, multivariate statistical techniques, including Pearson’s correlation coefficient, principal components analysis, and dendrogram cluster analysis are performed. Results revealed that sources of trace elements were identified to be geologic and little from human activities, i.e., application of agrochemicals, excess water mining, and industrial wastewater. It was recognized that the elevated concentration of trace elements in samples was caused by geogenic factors rather than manmade activities. Groundwater in this area poses a large threat due to high levels of trace metals, without any purification, it is essential to avoid this water for drinking. It advised that the groundwater quality should be constantly monitored for sustainable water quality management in the study zone.

A diagnostic study of heavy rainfall events in upper Ganga and Sharda river basins, India

A diagnostic study of heavy rainfall events in upper Ganga and Sharda river basins, India

Modelling Distributions of Asian and African Rice Based on MaxEnt

Rice landraces, including Asian rice (Oryza sativa L.) and African rice (Oryza glaberrima Steud.), provide important genetic resources for rice breeding to address challenges related to food security. Due to climate change and farm destruction, rice landraces require urgent conservation action. Recognition of the geographical distributions of rice landraces will promote further collecting efforts. Here we modelled the potential distributions of eight rice landrace subgroups using 8351 occurrence records combined with environmental predictors with Maximum Entropy (MaxEnt) algorithm. The results showed they were predicted in eight sub-regions, including the Indus, Ganges, Meghna, Mekong, Yangtze, Pearl, Niger, and Senegal river basins. We then further revealed the changes in suitable areas of rice landraces under future climate change. Suitable areas showed an upward trend in most of study areas, while sub-regions of North and Central China and West Coast of West Africa displayed an unsuitable trend indicating rice landraces are more likely to disappear from fields in these areas. The above changes were mainly determined by changing global temperature and precipitation. Those increasingly unsuitable areas should receive high priority in further collections. Overall, these results provide valuable references for further collecting efforts of rice landraces, while shedding light on global biodiversity conservation.

Morphometric delineation of administrative boundaries and classification of threatened categories of small watersheds in transboundary rivers

The ecological conservation of large rivers is impossible unless immediate attention is given to protecting their small tributaries at local levels. The natural boundaries of large river basins are shrinking because their tributaries and streams of different orders are disappearing at an unprecedented rate. Delineation of the fixed administrative boundaries (AB) to protect the natural boundary of small rivers and their classification into appropriate threatened categories, the present study was carried out on the 54.08 km long Banki River in the Ganga River basin. The > 70% irreversible loss in the number of streams (Nu), length of streams (Lu), and drainage density (Dd) resulted in the conversion of the 6th order Banki into the 4th order river. The extreme morphometric changes result in the Banki watershed being under the “Critically Endangered” category. The drainage density ratio (DdR) and mean stream width (Msw) were used to determine the width of AB (WAB). The “River Red List Categories and Criteria” are being proposed to strengthen global initiatives at the local levels to protect and conserve inland water bodies and transboundary rivers.