Lateral terrestrial water flow schemes for the Noah-MP land surface model on both natural and urban land surfaces

Abstract

Soil moisture plays an important role in numerical weather forecasting and climate projection studies. Surface runoff is significant not only in soil moisture monitoring but also in flood forecasting. However, the current Noah land surface model with multi-parameterization options (Noah-MP) is nearly vertical and one-dimensional, and it does not consider surface water ponding and overland flow. To address this, lateral terrestrial water flow schemes has been developed for Noah-MP on both natural and urban land surfaces to improve the simulation of soil moisture. These schemes have enabled the conversion of Noah-MP to a three-dimensional land surface model (Noah-MP-3D). Water balance schemes for natural and urban surfaces have also been developed and coupled with Noah-MP-3D to improve water inundation simulation. The performance of Noah-MP and Noah-MP-3D has been compared and validated at two soil moisture observation sites. The results indicate that after using the terrestrial lateral flow schemes has significantly improved the simulations for 10 cm and 40 cm volumetric soil moisture.