Hyperresolution global land surface modeling: Meeting a grand challenge for monitoring Earth's terrestrial water

Abstract

[1] Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (∼10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 10 9 unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a "grand challenge" to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

Groundwater and Surface Water Interaction at the Regional-scale – A Review with Focus on Regional Integrated Models

“…As the links between groundwater and surface water are of the utmost importance with respect to the integrated management of water resources (e.g. Winter et al 1998;Wood et al 2011), the question of how GW-SW at the regional scale can be studied/analysed/understood must be recognised as essential. Despite this, it seems that there is very little guidance available in scientific publications about how to approach GW-SW at the regional scale.…”

“…& Should models be as simple or as complex as possible (see, e.g. Beven and Cloke 2012;Wood et al 2011;Wood et al 2012)? & How should we deal with heterogeneity, how do we scale up processes, properties and model parameters (see, e.g.…”

Modelling Freshwater Resources at the Global Scale: Challenges and Prospects

“…Current efforts include the establishment of testbeds, overcoming of computational challenges and the compilation of input data sets. For further information on motivation, challenges and prospects of hyperresolution global hydrological modelling, please refer to Wood et al (2011) (including a comment of Beven and Cloke 2012 and the reply of Wood et al 2012) and Bierkens et al (2015). Beven et al (2015) provide valuable critical comments on hyperresolution modelling of water on the land areas of the globe, pointing out that unknown heterogeneities in the subsurface and ignorance about subsurface processes result in a lower gain of accuracy by increased resolution than is the case in atmosphere and ocean modelling.…”

POLARIS: A 30-meter probabilistic soil series map of the contiguous United States

“…However, there are challenges that limit SSURGO's use for other purposes including: variable quality and spatial detail between soil surveys, artificial discontinuities at political boundaries, and incomplete spatial coverage (Zhu et al, 2001;Gatzke et al, 2011;Thompson et al, 2012;Subburayalu and Slater, 2013;Du et al, 2014;. These challenges must be addressed to fully use SSURGO in contemporary applications such as climate and hydrologic models that require high quality and spatially complete soil information over continental extents (Wood et al, 2011;Bierkens et al, 2014;Chaney et al, 2014;Hengl et al, 2014). One promising path forward is through digital soil mapping (DSM).…”