Spatially distributed sensitivity of simulated global groundwater heads and flows to hydraulic conductivity, groundwater recharge, and surface water body parameterization

摘要: Abstract. In global hydrological models, groundwater storages and flows are generally simulated by linear reservoir models. Recently, the first gradient-based models were developed in order to improve representation of groundwater–surface-water interactions, capillary rise, lateral flows, human water use impacts. However, reliability model outputs is limited a lack data uncertain assumptions that necessary due coarse spatial resolution. The impact quality presented this study showing sensitivity changes only available hydraulic conductivity dataset. To better understand output spatially distributed parameters, we present application method for global-scale using nearly 2000 steady-state runs model G 3 M. By applying Morris novel domain decomposition approach identifies response units, parameter sensitivities determined computationally expensive model. Results indicate globally heads equally sensitive conductivity, recharge, surface body elevation, though vary regionally. For large areas globe, rivers be either losing or gaining, depending on combination, indicating high uncertainty simulating direction flow between two compartments. Mountainous dry regions show variance head numerical instabilities model, limiting computed these regions. This likely caused elevation. We conclude maps can help complex behavior incorporate with varying uncertainties. The findings support selection possible calibration parameters anticipate challenges transient coupling