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This study focuses on a hydro-meteorological variable, streamflow, and its vulnerability to global warming. In this study, we analyze monthly streamflow in 40 catchments across four major South Indian River basins: Cauvery, Godavari, Krishna, and Mahanadi, within the Indian Peninsular region. The chosen catchments have available streamflow series records ranging from 41 to 49 years, spanning from 1970 to 2018. To uncover trends in the streamflow datasets, an innovative technique called Innovative Polygon Trend Analysis (IPTA) is used. IPTA detects trend transitions between successive time series parts and identifies possible trend pieces within a year, crucial for agricultural and irrigation practices. Results reveal diverse polygon patterns across different catchments, reflecting non-systematic streamflow variation. Non-systematic changes occur primarily in the Cauvery basin, followed by the Godavari, Krishna, and Mahanadi basins. Varied trends—increasing and decreasing—are dispersed across different catchments. Increasing trends were generally observed in the standard deviation of streamflow, while decreasing trends were more widespread in the mean of streamflow. Notably, the Godavari basin displays more prevalent decreasing trends in the majority of catchments for different months, followed by Cauvery and Krishna. Mahanadi basin has more catchments showing an increasing trend than other basins. The results of this study provide deeper insight into the streamflow dynamics within these four basins. [ABSTRACT FROM AUTHOR]

The expression C = π D, which gives the relationship between the circumference C and the diameter D of a circle, is one of the few formulas known to almost all children and adults, regardless of how long they have been out of school. School-going children are introduced to this relation in their 7th grade. How this is done in India is illustrated by a snapshot from a textbook (NCERT, Mathematics, Grade 7, Chapter 11, [1].) There is no reference as to who proved it first, leave aside any proof of this fact. More so at no stage in the school curriculum, there is a reference to a proof of this for self-study. The aim of this article is to provide arguments that are rigorous and accessible to upper middle-grade students to illustrate the fact that C/D is constant for every circle. [ABSTRACT FROM AUTHOR]

The present study is taken up to record variations in the extent of area of two polygons—(i) a ground measured area of a university campus, (ii) enclosing the Ganga basin—and to examine the changes in both shape and area of another (iii) polygon covering India under different map projections with various parameters. The exercise brought forth interesting results. Depending on final ranks worked out based on minimum differences in extent of areas and shape distortion in the case of India, it is suggested to adopt either (i) Lambert Conformal Conical (LCC) projection with Everest India-Nepal datum, First Standard Parallel (FSP) 24.50, Second Standard Parallel (SSP) 28.50, Latitude of Origin (LO) 16.253259, Central Meridian (CM) 80.8749 or (ii) LCC projection with WGS 84 datum, FSP 24.50, SSP 28.50, LO 16.253259, CM 80.8749 or (iii) Polyconic with Everest India-Nepal datum, CM 84.50, LO 13.00, for mapping both smaller areas on larger scales and larger areas on smaller scales. [ABSTRACT FROM AUTHOR]

Numerous isolated teeth recovered from the Upper Triassic Tiki Formation of India have high, cylindrical, triangular to conical crowns with serrated mesial and distal carinae, and oval/subcircular and elliptical crown bases. Within this overall morphology, the teeth are subdivided into six morphotypes based on crown proportions, nature of carinae and serration and crown-base ratios. These ziphodont teeth are compared with those of other dominant Late Triassic carnivores of India to show similarity with that of the phytosaurs based on their shape, recurved nature, crown proportions, the presence of carina(e), nature of serrations and serration density. The different morphotypes reflect positional heterodonty, and three upper jaw dental sets are identified. This finding is corroborated by PCA, where the morphotypes form distinctly separate clusters, though partial overlapping of these convex hull polygons suggests that these teeth belonged to a single phytosaur taxon. As tripartite dentition is a derived condition; it may be concluded that these isolated teeth belonged to a more derived phytosaur, yet to be recovered from the Tiki Formation. The study highlights the importance of examining isolated teeth in order to identify the fossil forms which are yet to be discovered. [ABSTRACT FROM AUTHOR]

A new rich and varied assemblage of archosauriform teeth is reported from the Upper Triassic Tiki Formation of India. Twelve morphotypes are identified based on their distinctive morphology, crown proportions, nature of serrations/denticles and serration density. Morphotypes I and II show similarity with that of Galtonia and Protecovasaurus, respectively, whereas morphotypes III–VI have low, subtriangular or leaf-shaped, asymmetrical, labiolingually compressed crowns with lenticular-subcircular bases and are diagnosed as belonging to different indeterminate archosauriforms. Morphotype VII shows similarity with aetosaur teeth, whereas morphotypes VIII–XII are ziphodont teeth having high, cylindrical, recurved crown with labiolingual compression, serrated carinae and subrectangular serrations, and are theropod-like. Variation in dental histology is noted between these morphotypes based on extent of pulp cavity, dentinal tubules and von Ebner lines of incremental growth. In multivariate analyses, there is considerable overlapping of convex hull polygons with morphospaces of other known archosauriforms such as Protecovasaurus, Crosbysaurus and Tecovasaurus known from the lower Tecovas Formation of the Chinle Group, USA. Such similarity correlates the two horizons despite wide geographic separation, suggesting that the age of the Tiki Formation may be younger than that previously suggested. Based on the known fossil flora and fauna, a mid-late Carnian age is proposed for the Tiki Formation. [ABSTRACT FROM AUTHOR]

We investigate the columnar joints of the Rajmahal Trap (India) in detail to understand the maturity with respect to its eruptive centre. The fabrics in the massive columnar basalt of the study area are investigated using Anisotropy of Magnetic Susceptibility (AMS) studies prior to the maturity analysis. Fabric analysis reveals that rocks are devoid of any tectonic deformation and the columnar structures that are observed in them are necessarily primary. The maturity analysis has been implemented using a number of maturity indices, such as Voronoi polygons, hexagonality index, uniformity in mean side length, mean area and mean internal angle of the polygons, and also by the distribution of the number of polygon sides. The Voronoi polygon analysis for Rajmahal Trap suggests that the diameter ratio ranges from 1.38 to 1.52, thus indicating the same maturity as Voronoi polygon sets. The hexagonality index depicts that the maturity increases away from the fissure point towards the periphery, where six sided columns with smaller area and side length are observed. It is found that as the maturity increases, column mean side length as well as column mean top area decreases, while average number of column sides increases. We envisaged that the difference between ambient and the magma temperature played an important role in controlling column maturity. Based on the overall maturity studies, we conclude that maturity of the columnar joint increases away from the eruptive centre, towards the peripheral part of the Rajmahal Trap. [Display omitted] • Columnar joints of Rajmahal Trap are investigated to comment on thermal maturity. • Several maturity indices are used to understand thermal maturity. • Maturity of columnar joints are determined with respect to the eruptive centre. [ABSTRACT FROM AUTHOR]