A Study of the Sensitivity of Land Surface parameterizations to the Inclusion of Different Fractional Covers and Soil Textures

Abstract

The inclusion of processes relating to soil type and vegetation is very important in an attempt to improve a land surface parameterization for use in different scale atmospheric models. There is already sample micro-meteorological information about the sensitivity of surface energy fluxes and hydrology to plant communities, fractional plant covers, and some soil parameters, but not to soil texture. This study is concerned with the question of how much the land surface parameterization is sensitive to the inclusion of different fractional plant covers and soil-texture classes. The plant community used at the atmosphere-land interface in the sensitivity tests was a maize canopy planted at the experimental site De Sinderhoeve, the Netherlands, in the growing season of 1988. Four days at different stages of maize growth have been selected. For the time integrations in the sensitivity tests, a one-dimensional biophysical scheme was used. Nine soil textures have been chosen for simulations in the sensitivity tests. First, the model accuracy was established with observations using the soil texture, which approximately corresponded to the texture of the soil type where the experimental site was located. Then the authors investigated the sensitivity of the other soil textures for the fixed vegetation data and atmospheric conditions. Using the surface fluxes as the output, the sensitivity of the land surface parameterization scheme to the prescribed soil textures and fractional vegetation covers was established.