HydroBlocks v0.2: enabling a field-scale two-way coupling between the land surface and river networks in Earth system models

Abstract. Over the past decade, there has been appreciable progress towards modeling water, energy, and carbon cycles at field scales (10–100 m) over continental to global extents in Earth system models (ESMs). One such approach, named HydroBlocks, accomplishes this task while maintaining computational efficiency via Hydrologic Response Units (HRUs), more commonly known as “tiles” ESMs. In these HRUs are learned a hierarchical clustering approach from available high-resolution environmental data. However, until now yet be river routing that is able leverage HydroBlocks' field-scale heterogeneity; bridging gap will make it possible formally include riparian zone dynamics, irrigation surface interactive floodplains model. This paper introduces novel dynamic scheme HydroBlocks intertwined with modeled land heterogeneity. Each macroscale polygon (a generalization of concept grid cell) assigned its own fine-scale network derived very high resolution (∼ 30 digital elevation (DEMs); inlet–outlet reaches domain's polygons then linked assemble full network. The dynamics solved reach-level kinematic wave assumption Saint-Venant equations. Finally, two-way coupling between each HRU corresponding established. To implement test 1.0∘ bounding box surrounding Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site northern Oklahoma (United States) used. results show (1) implementation leads differences simulated spatial heterogeneity energy balance, (2) limited number 300 per 0.25∘ required approximate fully distributed simulation adequately, (3) balance partitioning sensitive model parameters. resulting provides an effective efficient path forward enable networks state-of-the-art tiling schemes