Khangembam, SharmilaSingh, Kshetrimayum Krishnakanta2024-01-212024-08-142024-01-212024-08-142021-07-071866751110.1007/s12517-021-07649-4http://10.2.3.109/handle/32116/4121A multi-parameter approach comprising the Stiff diagram, Durov diagram, water table contour map, hydrochemistry, and stable isotope has been used to elucidate characteristics of hydrochemical facies along the groundwater flow across different geomorphic terrains in the Barak Valley of NE India. Three types of hydrochemical facies, (a) Na-HCO3-weak acid type, (b) Na-Mg-HCO3-carbonate-rich type, and (c) Na-Cl-Mg-Ca-HCO3-mixed type, characterize the groundwater. The facies evolve from the acidic type in the recharge zone to mixed type in the alluvial and flood plains. The Base Exchange Index (r-1) values indicate characterization of Na+-HCO3? type (r1 > 1). The Meteoric Genesis Index (r-2) reveals deep meteoric percolation type (r2 <1). The Chloro-alkaline Index-I and II indicate reverse cation anion exchange reaction as the main reaction. The lateral and vertical flows indicate that groundwater flows from the piedmont zone to the alluvial and flood plains. The HCA dendrogram shows three clusters belonging to the piedmont, alluvial, and flood plains, indicating spatial evolution of hydro-facies along the flow path. The isotopic constituents in the groundwater vary along with the flow path. The recharge area exhibits depletion of heavier isotopes (mean ?4.5�), which gradually becomes enriched (mean ?4.1�) along the flow path, towards the plains as the hydro-facies evolves from the Na-HCO3 type to mixed type. � 2021, Saudi Society for Geosciences.en-USBarak Valley, Northeast IndiaFlow pathGroundwaterHydrochemical faciesArticlehttps://link.springer.com/10.1007/s12517-021-07649-4