A review of hydro-geomorphic studies in the Ganga Plains: the emergence of a new interdisciplinary area of research

Ganga alluvial plains have attracted a diverse field of geoscientific research in the last few decades. Earlier studies were mostly focused on subsurface structure mapping using geophysical techniques followed by sedimentological and stratigraphic analyses of alluvial sediments of the Ganga Plains. Recent decades have witnessed the incorporation of hydrological data in geomorphic studies, which led to a new set of process-based studies and the application of physical models to understand the evolution and dynamics of fluvial systems in the alluvial plains. Novel methodologies, observed data of water and sediment fluxes, availability of high-resolution remote sensing datasets especially Digital Elevation Models (DEM) data for watershed modeling, and incorporation of hydrological and geomorphic models have resulted in new insights into this highly dynamic sediment dispersal system. Such quantitative understandings are essential to design scientific strategies for sustainable management of river systems, and flood hazards and to understanding river’s past and future through modeling approaches. Various hydro-geomorphic approaches, concepts, and applications have been initiated in the last two decades. We provide a systematic review of these advances and highlight the emergence of a new research area for geomorphic inquiry at a modern time scale with a major emphasis on the quantitative understanding of cause-effect relationships. Finally, a new set of research questions has been suggested with the prospect to define some of the necessary required research directions in the future studies of the Ganga Plains.