An Unstructured Mesh Generation Tool for Efficient High-Resolution Representation of Spatial Heterogeneity in Land Surface Models

This study develops an unstructured mesh generation tool for land surface modeling using a multi-scale hexagon discrete grid. The tool can automatically determine the required grid resolution for different regions based on multi-objective criteria such as elevation, slope, land cover, and land use. The refined unstructured meshes demonstrate significant enhancement in the representation of spatial heterogeneity. The tool is coupled with the Common Land Model (CoLM) to enable land surface simulations using unstructured grids. Evaluations focused on runoff, river discharge, and inundation indicate improved model performance compared to traditional grid-based CoLM simulations under the same computational cost constraints. This tool provides new capabilities for more efficiently capturing localized land surface processes and extreme events.