New perspective for eco-hydrology model to constrain missing role of inland waters on boundless biogeochemical cycle in terrestrial–aquatic continuum

Recent research shows that inland water may play some role in carbon cycling though its contribution has remained uncertain due to a limited reliable data. From the viewpoint of scale similarity and discontinuity of eco-hydrological processes, it is important to identify spatial coupling of ecosystems including energy, materials, and organisms flows across their boundaries. One of the fundamentals of eco-hydrology model is to incorporate a complex relation between soil, water, temperature, plant, and carbon. In this paper, the author reviewed previous progress in eco-hydrology model focusing on surface–groundwater connectivity and hydrologic–geomorphic–ecological processes interaction. He also reviewed the recent progress in modeling, the role of inland water on biogeochemical cycle by compiling various datasets of hydrological and biogeochemical cycle. Then, he showed a new advanced model coupling eco-hydrology and biogeochemical cycle (NICE-BGC). The model results of both CO2 evasion and carbon transport to the ocean were reasonably in good agreement with previous data. In order to decrease uncertainty about carbon cycle, it became clear the previous empirical estimation should be extended to this process-oriented model and higher resolution data to further clarify mechanistic interplay between inorganic and organic carbon and its relationship to nitrogen and phosphorus in terrestrial–aquatic linkages. NICE-BGC would play important role in re-evaluation of greenhouse gas budget of the biosphere, quantification of hot spots, and bridging gap between top-down and bottom-up approaches in global carbon budget. This will also help to integrate knowledge and provide understanding needed for reaching sustainability by 2030 in UN Sustainable Development Goals.