Central Ganga Plain Research Articles

Climatic Oscillations and Dynastic Trends: A Multiproxy analysis of the past two millennia in the Indian Subcontinent

The study examines centennial-scale climatic oscillations over the past two millennia in the monsoon-dominated Indian subcontinent by multiproxy analysis of pollen along with stable carbon isotope, total organic carbon, magnetic susceptibility, and grain size from a 274 cm deep sediment profile in Sarsapukhra Lake, Varanasi, in the Central Ganga Plain (CGP) to portray vegetation changes and their impact on rise and fall of dominant dynasties. Between ∼1800 to 1600 cal yr BP, the coarser silty sand with few Poaceae and Asteraceae pollen with other proxy data, indicate that the region experienced a strong Indian Summer Monsoon (ISM). Subsequently, from ∼1600 to 1350 cal yr BP, presence of mixed moist deciduous taxa such as Shorea robusta, Madhuca indica, Rubiaceae, Morus alba, Syzygium, and Moraceae indicate a moderate ISM while between 1350 to 1200 cal yr BP, the dominance of dry deciduous taxa viz. Acacia sp., Bombax ceiba, Holoptelea, Rutaceae, Madhuca indica, Mangifera indica etc. suggested weak ISM conditions. A pulsative ameliorating trend from ∼1200 to 1030 cal yr BP showed the dominance of deciduous taxa such as Holoptelea, Rutaceae, Ziziphus, Rubiaceae, Maytenus and Acanthaceae etc. indicating warm and moist climatic conditions, followed by a weak ISM until ∼900 cal yr BP and improved ISM until 620 cal yr BP. Subsequently, an improving trend in the ISM from ∼620 to 450 cal yr BP was observed, with increased dominance of wetland taxa, followed by acute dry climate beyond ∼450 cal yr BP indicating poor ISM conditions.Additionally, the alternating warm and cold episodes had a direct impact on vegetation, forcing human civilizations to migrate from their original locations and contributing to the downfall of prominent dynasties. Furthermore, this study lays the foundation for future research into issues related to vegetation change, the amount of ISM shift, and human culture−climate relationship.

Coupled role of climate and tectonics in the deposition of the late Quaternary sedimentary sequence in the southern margin of the central Ganga Plain, India

ABSTRACT The Ganga Plain’s sedimentation is primarily controlled by Himalayan tectonics, variations in monsoon intensity, and glacier size. However, the significance of intrabasinal tectonics, which is an interplay of the Himalaya tectonics and basement tectonic configuration of the Ganga Plain, in comprehending the late Quaternary Ganga Plain sedimentation remains unclear. In this study, the sediment provenance and extent of weathering experienced by the sediments are studied using the mineralogical and geochemical (major, trace, and rare earth elements) composition of a sedimentary cliff sequence exposed at the Ramnagar locality near the cratonic peripheral bulge in the southern Ganga Plain. In the Ramnagar cliff sediment section, two sediment packages, designated SP-A and SP-B, are identified based on mineralogy, texture, and geochemistry. These packages of sediments show mild chemical weathering and distinct geochemical compositions. The lower part (SP-A) of the Ramnagar cliff section is characterized by higher contributions from mafic sources (pyroxene, feldspar, and mica as dominant minerals), while the upper part (SP-B) is predominately derived from felsic sources (mica and feldspar as dominant minerals), which are supplied via the peninsular and the Himalayan rivers, respectively. The southern part of the central Ganga Plain shows evidence of a shift in the sediment provenance from mafic to felsic source rock at 40 ka. This study demonstrates how weathering and sedimentation are controlled by both regional tectonics and climate in the southern margin of the central Ganga Plain.

Millennial to centennial-scale climate oscillations since 15000 cal yrs BP from Kanwar wetland in the Central Ganga Plain, India

Millennial-scale climate cycles have been meagerly discussed in the terrestrial records from the Indian subcontinent, particularly the wetlands of the Ganga Plain. The mineral magnetic and textural analyses, along with chronology, distinctly record variation in the monsoon intensity since 15000 cal yrs BP in the sediment core collected from the Kanwar Lake in the Central Ganga Plain (CGP) of India. This unique high-resolution data allowed us to analyse monsoon fluctuation in the CGP with respect to changes in the North Atlantic process (internal) and external (solar cycles) forcing. During this period, several palaeoclimatic events, such as the Bølling-Allerød (B/A), Older and Younger Dryas, and the high-frequency fluctuations in the Holocene viz., Greenlandian, Northgrippian, and Meghalayan stages, were observed. The B/A event is correlated with the Indian Summer Monsoon (ISM) intensification period of the CGP. Eleven dry events are recorded at 13600–13200, 13000–11700, 11000, 10600, 9800–9000, 8200, 6100–5300, 4300–4200, 3800, 1800–900 and 300 cal yrs BP. During the Holocene, the sustained episodes of weaker monsoon centered around 10600, 9600, 8200, 6000, 4200, 2800, 1400 and 600 cal yrs BP, where the variability of the proxy data is mostly synchronous with the reduced upwelling intensity in the western Arabian Sea as well as roughly align with ∼1500 years cyclic signals in the drifted ice proxy recorded Bond Events indicating weakened ISM circulation during colder North Atlantic. Two distinct short cycles, spanning 172–344 and 172–688 years, are evident around 12,000 and 14,000 cal yrs BP with an additional occurrence from 86 to 344 years during 2000 and 6000 cal yrs BP, affirming the significance of external forcing, particularly solar activity. For the 1492 years cycle in ISM fluctuation, we postulate it may represent a combined forcing of external (solar) and internal (Atlantic Meridional Overturning Circulation (AMOC)) factors during the Holocene. This is the first high-resolution record available in the CGP, which brings out crucial monsoon reconstruction during the last 15000 years.

Facies architecture and textural attributes of the Late Quaternary cliff embankment sections of the Sai River, Central Ganga Plain, India

Facies architecture and textural attributes of the Late Quaternary cliff embankment sections of the Sai River, Central Ganga Plain, India

Monitoring hydroecology and climatic variability since ~4.6 ka from palynological, sedimentological and environmental perspectives in an Ox-bow lake, Central Ganga Plain, India

The Ganga-Sai River Interfluve contains several ox-bow lakes in the fertile Central Ganga plains (CGP). A ~2.20-meter deep sedimentary profile obtained near the Chandra Shekhar Azad bird sanctuary (Nawabganj lake-NL) of the CGP was studied to understand the evolution of the ecosystem and climate using pollen/spores, diatoms, testate amoebae, environmental magnetic data,and carbon and nitrogen isotopes. This sedimentary profile is chronologically well-constrained by five radiocarbon (14C) dates. Between 4.6 and 4.4 ka, the sandy sediment and pollen evidence for riparian forest, the absence of aquatic pollen and sponge spicules suggest scant water in the vicinity through the river channel. A semi-closed fluvial ecosystem between 4.4 and 4.2 ka is indicated by testate amoebae, sponge spicules and arboreal pollen. At least two intermittent warm conditions prevailed between 4.6 and 4.2 ka. Between 4.2 and 2.8 ka, high aquatic pollen, diatoms and testate amoebae indicate a lake ecosystem. By ~2.8–0.9 ka the gammoscleres from sponges formed during dry seasons indicate recharging during monsoon as the river shifted. Thereafter, agricultural pollen ( Brassica and Apiaceae) indicates a further shift in the lake boundary exposing land. The highly sandy texture, fluctuating δ13C, δ15N and magnetic mineral values indicate an unstable fluvio-lacustrine deposition inducing hydroecological changes influenced by intermittent about 5–6 humid and dry climatic conditions since ~4.6 ka to present. The calcrete layer in the bottom sediments shows high aridity in CGP between ~5 and 4.6 ka reaching the climax cold-dry event of ~4.2 ka recorded worldwide. The spectral analysis of palynological data from NL and the contemporary Barela Lake, reveals de Vries and Gleissberg cycles of low and high solar irradiance at centennial to multi-centennial scale during the Holocene. The impact on vegetation, sediment depositional dynamics, and shift in river channel was more rapid showing the dominance of ~200 years. periodicity post ~5 ka as compared to ~300 years of dominance prior to this. This centennial timescale is of great speculation for future climate predictions in CGP coupled with the anthropogenic forcings.

Drainage Network Analysis and Tectonics Interference of the Reth River, Central Ganga Plain (India) Using Geospatial Technology

Drainage Network Analysis and Tectonics Interference of the Reth River, Central Ganga Plain (India) Using Geospatial Technology

Modern biotic and abiotic analogues from the surface soil of Ganga-Ghaghara-Gandak interfluves of the Central Ganga Plain (CGP), India: Implications for the palaeoecological reconstructions

Modern surface analogue dataset combining biotic and abiotic proxies (i.e., pollen, phytolith, diatom, stable carbon and nitrogen isotopes of organic matter, soil geochemical and textural parameters together with magnetic susceptibility) were generated from the Ghaghara-Gandak and Ganga-Ghaghara interfluves of the Central Ganga Plain (CGP) to determine the extent to which comprehensive multiproxy data can distinguish different types of depositional sub-environments (lacustrine and fluvial deposits; cropland and forestland). This modern analogue aims to provide basis to reconstruct reliable palaeoecological changes of the CGP, India during the Late Quaternary. The pollen assemblages reflect the mixed deciduous forest under a warm and humid climate in response to rainfall variations in the region. The anthropogenic activities could be well observed in the CGP through marker pollen taxa like cereal, Solanaceae and Brassicaceae. The overall pollen, phytolith, and diatom data indicate a comparatively denser vegetation cover and ecological variability in the Ghaghara-Gandak interfluve than in the Ganga-Ghaghara region. The δ13C and TOC/TN values in the sediments indicate a mixed C3-C4 source of vegetation in the lakes and rivers of both the interfluves. However, the sediments from the forest floor indicate relatively lower δ13C values (-27.6 to 29.1‰), indicating the typical C3 source of vegetation. The low kurtosis values suggest fine-grained sediments combined with low-energy-level reworking in the two interfluves. The Principal Component Analysis (PCA) and Box-plot of the different proxy data was used to test if the soil from different depositional settings can be distinguished or not. Thus, the generated multiproxy data are consistent with the extant ecology and depositional setting, although some site-by-site variations were observed and are indicative of taphonomic bias, climatic alterations, geological, and anthropogenic factors. The present multiproxy analogue should be taken into account while reconstructing the past environment and ecology of the CGP and adjoining region.

Impact of Aquifer Sediments - Minerals - Groundwater Interaction on Hydrochemistry, Aligarh District, Central Ganga Plain, India

Abstract The sedimentological/mineralogical characteristics of the aquifer material have been determined and their impact on groundwater chemistry is evaluated in the Aligarh district. It is found that 35 % of the aquifer is characterized by sand fraction containing (17-8) % of plagioclase and rock fragment (4-5%). Dominant aquifer material (silt and clay) fraction is dominated by plagioclase, K-feldspar, calcite, chlorite, kaolinite/mica, and halite. Spatial variation in relative positions and thickness of aquifer of silt, clay, and sandy layers resulting to particular hydro-chemical types. Major ions in groundwater shows a high degree of spatial variation along with multisource for the ions. Water quality index suggests that 22% of the water samples fall under the unsuitable category in the area characterized by aquifer material dominant with clay layers. Groundwater types in the area are dominated by Na+–Cl– and Ca2+ – HCO3–, Ca+2 Mg+ – HCO3– Ca+2 Mg+2 – Cl– (mixed type). Silicate weathering, Carbonates, salt dissolution, and base ion exchange are the major mechanisms that control the major ionic composition of the groundwater. It is saturated with calcite, dolomite, chalcedony, and Mg-silicate (Sepiolite). The unstable Speiolite under climate conditions prevails in the region rapidly change to smectite clay, which constitutes a major clay mineral of Indo-Gangetic alluvium. ANN (Artificial Neural Networking) analysis indicated that irrigation quality parameters Permeability Index (PI) and Na% are showing strong relation with selected parameters EC, and Na+ concentration. SAR values mostly depend on Na+, Mg+2 conc. and EC, while residual sodium carbonate (RSC) of groundwater can be predicted using Mg2+, HCO3–, and Ca2+ concentration in groundwater.

Surface pollen quantification and floristic survey at Shaheed Chandra Shekhar Azad (SCSA) Bird Sanctuary, Central Ganga Plain, India: a pilot study for the palaeoecological implications

Accuracy of vegetation reconstruction portraying land cover of the past is based on a careful analysis of pollen production, dispersal and their quantitative deposition. The present attempt to integrate sampling of pollen–vegetation spectrum through Crackles Protocols for vegetation surveys, at three spatial zones with intervals of 0–10 m (A), 10–100 m (B) and 100–1000 m (C) at Shaheed Chandra Shekhar Azaad Bird Sanctuary in Uttar Pradesh with tropical dry deciduous forest, is a maiden approach. In these studies, the standard vegetation survey around the pollen surface sampling sites is prerequisite for quantifying pollen–vegetation relationship in modern analogues of the past. The underlying theory of this approach is based on the fact that the relative pollen productivity (RPP) is constant in space and time within a region or biome. The floristic survey of the sanctuary is integral to this pilot study, Crackles Bequest protocol, and is intrinsic to run the Extended R–Value (ERV) model for obtaining estimates of relative pollen productivities (RPPs) for quantitative palaeoecological interpretations from tropical to subtropical forest covers in northern India. The modern pollen assemblage from surface sediment samples established the dominance of Poaceae pollen, along with those of Acacia, Albizia and Mimosa species. The multivariate principal component analysis (PCA), applied to quantify the data on the survey of different vegetation communities revealed that out of the four identified vegetation communities, community D consisted of herbaceous patches including Ageratum, Parthenium, Rumex, Tephrosia, Eclipta alba, Oxalis, Cannabis and Launea, community B mainly comprised of tree taxa like Terminalia, Barringtonia and Pongamia, whereas the communities A and C represented mixed vegetation comprising of trees, shrubs and herbs. The present maiden analysis through the Crackles Bequest protocol method served as a preliminary step to establish the quantitative ‘pollen–based’ vegetation reconstruction in the Gangetic Plains of Central India and is expected to serve as a model for similar studies in other regions. सारांश अतीत के भू-आवरण को चित्रित करने वाले वनस्पति पुनर्निर्माण की सटीकता पराग उत्पादन, फैलाव और उनके मात्रात्मक जमाव के सावधानीपूर्वक विश्लेषण पर आधारित है। शहीद चंद्र शेखर आज़ाद (एससीएसए) पक्षी अभयारण्य, मध्य गंगा मैदान से 0-10 मीटर (ए), 10-100 मीटर (बी) और 100-1000 मीटर (सी) के अंतराल में तीन स्थानिक क्षेत्रों में, वनस्पति सर्वेक्षण के लिए क्रैकल्स प्रोटोकॉल के माध्यम से पराग-वनस्पति स्पेक्ट्रम के नमूने को एकीकृत किया गया। यह भारत के उष्णकटिबंधीय शुष्क पर्णपाती वन से किया गया प्रथम प्रयास था। पुरावनस्पति एवं पुरापारिस्थितिकी को समझने के लिए पराग-वनस्पति संबंधों को निर्धारित करने की आवश्यकता है। आधुनिक सादृश्य को स्थापित करने के लिए पराग सतह नमूना स्थलों के आसपास मानक वनस्पति सर्वेक्षण अनिवार्य है। इस दृष्टिकोण का अंतर्निहित सिद्धांत इस तथ्य पर आधारित है कि सापेक्ष पराग उत्पादकता (आरपीपी) एक क्षेत्र या बायोम में स्थानिक व लौकिक रूप से स्थिर है। अभयारण्य का वनस्पति सर्वेक्षण इस मूल अध्ययन, क्रैकल्स बेक्वेस्ट प्रोटोकॉल का अभिन्न अंग है, और उत्तरी भारत के उष्णकटिबंधीय से उपोष्णकटिबंधीय वनों में मात्रात्मक पुरापारिस्थितिक व्याख्याओं के लिए सापेक्ष पराग उत्पादकता (आरपीपी) के अनुमान प्राप्त करने के लिए विस्तारित आर-वैल्यू (ईआरवी) मॉडल को चलाने के लिए वास्तविक है। सतह तलछट के नमूनों से आधुनिक पराग जमाव ने अकेसिया, अल्बिजिया और माइमोसा प्रजातियों के साथ-साथ पोएसी (घास) पराग के प्रभुत्व को स्थापित किया है। विभिन्न वनस्पति समुदायों के सर्वेक्षण पर डेटा की मात्रा निर्धारित करने के लिए लागू बहुभिन्नरूपी प्रमुख घटक विश्लेषण (पीसीए) से पता चला है कि चार पहचाने गए वनस्पति समुदायों में से, समुदाय ‘डी’ में एजेरटम, पार्थेनियम, रुमेक्स, टेफ्रोसिया, एक्लिप्टा अल्बा, ऑक्सलिस, कैनाबिस और लाउनिया सहित गैर-वृक्षीय प्रजातियों के समूह शामिल हैं। समुदाय ‘बी’ में मुख्य रूप से टर्मिनलिया, बैरिंगटोनिया और पोंगामिया जैसी वृक्षीय प्रजातियाँ शामिल हैं, जबकि समुदायों ‘ए’ और ‘सी’ ने पेड़ों, झाड़ियों और जड़ी-बूटियों से युक्त मिश्रित वनस्पति का प्रतिनिधित्व किया। क्रैकल्स बेक्वेस्ट प्रोटोकॉल पद्धति के माध्यम से वर्तमान प्रथम विश्लेषण, मध्य भारत के गंगा के मैदानों में मात्रात्मक 'पराग-आधारित' वनस्पति पुनर्निर्माण स्थापित करने के लिए एक प्रारंभिक कदम है, और अन्य क्षेत्रों में इसी तरह के अध्ययन के लिए यह एक प्रतिमान के रूप में कार्य करेगा।

Assessment of groundwater quality using Entropy-Weighted Quality Index (EWQI) and multivariate statistical techniques in Central Ganga plain, India

Assessment of groundwater quality using Entropy-Weighted Quality Index (EWQI) and multivariate statistical techniques in Central Ganga plain, India

Geomorphic Analysis of Baghain River, Yamuna Basin, and its Implication for Drainage Characteristic and Tectonics using Remote Sensing and GIS Techniques

Abstract The present study aims to access the geomorphic analysis of the Baghain river basin and its implication on landscape evolution. Baghain river originates from the Panna hill, and flows through marginal and central Ganga plain. It empties itself in to Yamuna river near Chilla village, Banda district, Uttar Pradesh. The river basin comprises of three major geological units associated with this basin: Bundelkhand gneissic complex, Vindhyan Supergroup (hard rock terrain known as Panna hill) and Alluvial deposit (marginal Ganga plain and central Ganga plain). The current work focuses on study of morphometric parameters and geomorphic indices of Baghain river basin using digital elevation model (DEM) and topographic maps (1:50,000 scale). This basin exhibits four types of drainage patterns: dendritic, parallel, trellis and rectangular. Bifurcations ratio (4.82) of river basin suggest that the most part of the basin is not influenced by any geological structures. The elongation ratio (0.50) suggests that the basin is moderately elongated. The drainage density (0.62) and stream frequency (0.22) also suggest that the basin has moderate to high permeable and easily erodible alluvium terrain. The escarpment height is low in the proximal part (Panna Hill) and high in the middle and distal parts of the basin (marginal Ganga plain and central Ganga plain, respectively. Asymmetric factor (52) shows a leftward tilt of the basin. The region lies under marginal Ganga plain, and Bundelkhand plateau. The sharp bend present is probably due to the lithological variation. It reflects moderate gradient in the upper part (Panna hill), steep gradient in the lower part (Panna hill), and low gradient in the marginal to central Ganga plain.

Spatiotemporal assessment of groundwater quality in the Central Ganga Plain, India, using multivariate statistical tools.

In the present study, the water quality status of the Sadar block in Pratapgarh district of Uttar Pradesh, India, was calculated by Water Pollution Index (WPI) using 15 groundwater quality parameters (pH, turbidity, EC (electric conductivity), TDS (total dissolved solids), salinity, total hardness, Ca2+, K+, Mg2+, Na+, Cl-, F-, SO42-, HCO3-, and NO3-) at 40 different study locations. It is found that 10%, 25%, and 65%, of samples, fall under the good, moderately polluted, and highly polluted category, respectively. Irrigation suitability of groundwater has also been evaluated by using irrigation suitability parameters, i.e., Sodium Absorption Ratio (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly Ratio (KR), Percentage Sodium (% Na), and Magnesium Hazards (MH). Based on the analysis, it was determined that most of the samples were suitable for irrigation in the area. Irrigation practices are found to be unsuitable for Kelly's ratio of 37.5%, MH 60%, and RSC 55% samples. WPI and Pearson's correlation matrix (PCA) have suggested a significant linear relationship among the water quality parameters based on the test results. The Gibbs plot indicates that the majority of samples fall under the "evaporation dominance" category while the rest fall under the "rock weathering dominance" suggesting that the complex geochemical mechanisms are active in the study area. This study would be very helpful to government authorities and it would aid them to suggest alternate drinking water resources in affected areas.

Flood Hazard and Risk Assessment of Deoha River Basin, Central Ganga Plain, India: An GIS approach

Flood is a natural disaster worldwide and it occurs primarily in any plain area due to geological and environmental phenomena like geomorphological process, monsoonal effect, lithology etc. Such plains are also severely affected often by catastrophic flooding and are currently recommended to be the worst flood-affected region in the world. This research aims to classify the flood-prone areas of the Deoha River basin based on the weighted overlay assessment method using Arc-GIS-10 and ERDAS-14. by multi-criteria assessment, in which weights are assigned for each class based on multi parameters with restricted variables to prepare a map of the flood-prone areas. The average annual rainfall (80-200 cm), stream frequency (0.0001 to 0.3563 stream number/km2), slope (0-50-350), drainage density (0-545.94 magnitude/m2), channel gradient (0.27-22.52 m/km), landuse/landcover (cropland>water bodies>built-up>scrubland >forest.) and soil type (loam>sand>clay) prefer the susceptibility of flood-prone in the basin area. The weighting maps are generated by providing ranks and weights to these thematic maps. As a result, the flood hazard risk zonation map would show the total area vulnerable to hazards as very medium, low, moderate, high and very high-risk regions. By creating a risk zonation map, we will recommend measures to reduce the danger of these hazards in Deoha basin.

Insights from the palaeo-geomorphic features of the Central Ganga Plain, India: past to present

Insights from the palaeo-geomorphic features of the Central Ganga Plain, India: past to present

Ameliorating Effect of Organic Materials on Saline-Sodic Soil in Central Ganga Plain in Uttar Pradesh, India

ABSTRACT Field experiments were conducted for two years to evaluate the ameliorating effect of locally available diverse organic materials on saline sodic soil. The treatments comprised no-amendment (control), 100% GR (16.2 t ha−1), vermicompost, spent mushroom compost of Pleurotus ostreatus, farm yard manure, sheep dung and green manure (Prosopis julifera) each applied @ 10 t ha−1. Compared to 100% GR, the pooled EC reduced for two treatments spent mushroom compost and sheep dung (by 45 and 19%, respectively) while it was comparable (slight increased by 1.5%) for vermicompost. In 2019, soil pH for vermicompost and sheep dung was significantly on par with 100% GR, although this trend was insignificant in 2020. It can be concluded that vermicompost and sheep dung can be used in amelioration of sodic and saline sodic soil, respectively, and mushroom compost followed by natural leaching can be used in amelioration of saline soils.

The effects of Heavy Metals on Microbial Biomass of Forest Soil from Tropical Deciduous Forest of Central Ganga Plain

This investigation was aimed toward assessing the impact of heavy metals on soil microbial cycles. The impacts of lead (Pb) and cadmium (Cd) at various concentrations were researched over a time of about two months. Chloride salts of Pb and Cd were added independently and in blend to soil samples at room temperature (27ºC) in various polythene packs. Samples were taken from the sacks at about fourteen days span and estimations were taken of the microbial biomass carbon (MBC). The outcomes showed that there was a significant reduction in the microbial biomass carbon for all treated soils from the second week to the 6th week. However, on 8th week, increase in microbial biomass carbon was observed. At the 6th week, 2000mgkg-1Pb and 40mgkg-1Cd gave the main reduction (P < 0.05) in microbial biomass carbon of 98%. A critical decrease in biomass carbon in metal contaminated soil demonstrated that this parameter is a decent marker of toxicity of metals on soil microflora.

Impact of nutrient enrichment on habitat heterogeneity and species richness of aquatic macrophytes: evidence from freshwater tropical lakes of Central Ganga Plain, India

Impact of nutrient enrichment on habitat heterogeneity and species richness of aquatic macrophytes: evidence from freshwater tropical lakes of Central Ganga Plain, India

New evidence of mid- to late- Holocene vegetation and climate change from a Neolithic settlement in western fringe of Central Ganga Plain: Implications for Neolithic to Historic phases

Here we present a continuous palaeoclimatic record of 5980 years (7230 cal BP–1250 cal BP) from Hetapatti, a Neolithic site situated on the western fringe of the Central Ganga Plain. The region was a center of reurbanisation following the decline of the Harappan civilisation and is considered a hub of economic, political and religious evolution since the sixth millennium BC. Hetapatti contains an uninterrupted sequence from Neolithic to Historic (Gupta) period. The study integrates two different approaches (phytoliths and carbon isotope analysis) to infer vegetational and climatic changes and to understand their relationship to the cultural sequence. Our results show a gradual transformation from a warm and humid climate into a warm and dry climate from the Neolithic to Historic (Gupta) period. We find an abrupt weakening of the ISM at ~2080 cal BP driving a warm and dry climate. The comparison of our data with other high resolution regional and global records led us to hypothesise a synchronicity in this warm and dry trend, coeval with the Roman warm period (RWP). The observed variation in vegetation and climate might have driven by the fluctuations in the Indian Summer Monsoon (ISM). Additionally, the phytolith analysis provides evidence of cereal crops including rice, wheat, barley, millets, etc. suggesting a crop affinity with the earlier Indus crop package. It is interesting to note that the site displays an uninterrupted cultural sequence from Neolithic to Historic times, with artefacts of each phase exhibiting technological and stylistic developments from the preceding culture. From this we infer that the well adapted socio-ecological strategies and availability of perennial rivers may have helped the ancient civilisation to absorb the stress relating to a varying climate.

Water Quality Index Assessment of Groundwater in the Central Ganga Plain with Reference to Raebareli District, Uttar Pradesh, India

Water Quality Index Assessment of Groundwater in the Central Ganga Plain with Reference to Raebareli District, Uttar Pradesh, India

A Multi Criteria Approach for Morpho-tectonic Evaluation of Sai River Basin in Uttar Pradesh

Abstract The study integrates the morphometric analysis, lineament evaluation and fluvial geomorphology to investigate the morphotectonic setup of Sai basin. The Sai river basin forms an integral part of the central Ganga plain where the gentle slope is significantly controlled by intra-basinal tectonic activity. The fluvial setup of the Sai basin which comprises of vast old flood plains now is displayed as an entrenched river with straight channel symmetry with multiple sinuous bends. The structural control and geomorphic asymmetry can be well established by using multi criteria approach of morphometric parameters and lineament analysis. The morphometric analysis of the basin shows that the Sai river comprises of 5th order stream basin with high elongation ratio and high bifurcation ratio suggesting structural and tectonic controls. The form factor, drainage density, and length of overland flow shows low permeability with low infiltration rate indicating sheet erosion as a major denudational process. The lineament analysis from the stream pattern analysis indicates structural control for drainages while geomorphology corresponds to the landscape of the basin. The lineaments analysis shows a major NW-SE trend in concordance to present foreland basin. Thus, the study confirms that the Sai basin has conclusive evidences of morpho-tectonic control in the central Ganga plain indicating the role of the tectonics in basin evoluation.