From local scale to regional, continental, and global scales: coupling of eco-hydrology and biogeochemical cycle model in biosphere

Tadanobu Nakayama, Shamil Maksyutov

Wednesday 1 july 2015

10:00 - 10:15h at Central America (level 0)

Themes: (T) Water resources and hydro informatics (WRHI), (ST) Surface and subsurface flow interactions

Parallel session: 8H. Water resources - Catchment

Recent research shows inland water may play some role in continental carbon cycling though its contribution has remained uncertain due to a paucity of data (Battin et al., 2009). About scale similarity and discontinuity of eco-hydrological process, it is important to identify spatial coupling of ecosystems including energy, materials, and organisms across their boundaries. So, it is powerful to re-evaluate the ecosystems as extension of the metabolic theory of ecology (Brown et al., 2004) by considering multi-scaled aspects in the same way as the river continuum concept (Vannote et al., 1980). The author has developed process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama, 2008a-b, 2010, 2011a-b, 2012a-c, 2013; Nakayama and Fujita, 2010; Nakayama and Hashimoto, 2011; Nakayama and Shankman, 2013a-b; Nakayama and Watanabe, 2004, 2006, 2008a-b; Nakayama et al., 2006, 2007, 2010, 2012), which incorporates surface-groundwater interactions, includes up- and down-scaling processes between local-regional-global scales, and can simulate iteratively feedback between hydrologic-geomorphic-ecological processes. In this study, NICE was expanded from various catchments/basins (Changjiang, Yellow, and Mekong Rivers, West Siberia, Tokyo metropolitan area, and Japanese wetland) to global scale to evaluate eco-hydraulic and eco-hydrological processes and their impact on biogeochemical cycles in inland water. The model shows there is a great difference in hydrologic cycles including surface-groundwater interaction between them. NICE was further developed to incorporate biogeochemical cycle including reaction between inorganic and organic carbons in terrestrial and aquatic ecosystems accompanied by hydrologic cycle there. This advanced eco-hydrologic and biogeochemical coupling model would play important role on solution of water-related disasters and identification of full greenhouse gas balance of the biosphere (Cole et al., 2007; Battin et al., 2009).