These data are annual spatiotemporal gridded information in the South Asia domain (0.1 x 0.1 degree resolution) that enable hydrological flow modelling to be undertaken. Included are; animal (8 categories) and human populations, atmospheric deposition of reduced and oxidised nitrogen, fertiliser inputs to agricultural soils, catchment flow, drainage direction and urban land use. The data are annual from 1980 to 2035 (with some data on a fixed year; see supporting documentation) and are forecast on three separate scenarios post-2015. All data were collected or generated during the South Asian Nitrogen Hub (SANH - Global Challenge Research Fund, Grant Ref. Number NE/S009019/2).