Cold regions and drylands make up more than 50% of the Earth’s surface. High-rate land-cover changes triggered by global warming motivate urgent quantification and understanding of the earth-surface processes sculpting these landscapes. This session aims to reconcile results from field, laboratory, and numerical investigations of fluvio-deltaic processes in cold, sub(arctic) and arid regions. These areas are characterized by ephemeral flows, permafrost, and ice; elements not typically considered in studies focusing on temperate-humid or tropical settings. We seek contributions on hydrologic, morphological, and sedimentological characteristics of fluvio-deltaic systems, including (but not limited to) supraglacial streams, ice-covered and permafrost rivers, and ephemeral desert rivers and floodplains that support heterogeneous ecosystems and diverse habitats. Of particular interest is to showcase emerging interdisciplinary needs within the fluvial, dryland, and sub(arctic) research communities that call for better integration across a broad range of traditional disciplines such as geomorphology, ecology, hydrology, biogeochemistry, and sedimentology.