The main features of the hydrological module in the Land Air Parameterization Scheme (LAPS)

Abstract

This paper describes the hydrological module of the biophysical scheme named LAPS (Land-Air Parameterization Scheme) which is designed as a software package which can be included as part of an atmospheric model or as a stand-alone model. It includes: hydrological processes, bare soil transfer processes and canopy transfer processes. In the hydrological module the direct loss of liquid water across the scheme domain boundaries is considered as separate processes which can be summarised as follows: overland flow (when a precipitation excess is over infiltration capacity or when the surface becomes saturated), subsurface runoff (horizontal drainage from unsaturated flow) and vertical drainage through the lower scheme boundary. Moving from the top to the bottom of the soil, the water column has the three layers where the vertical water flow is considered according to Darcy's law. The performance of this module through long term integration, using HAPEX-MOBILHY data set are examined. © 1997 Elsevier Science Ltd.