PHYSICAL PROPERTIES OF AMAZONIAN SOILS - A MODELING STUDY USING THE ANGLO-BRAZILIAN AMAZONIAN CLIMATE OBSERVATION STUDY DATA

摘要

The hydraulic properties of some Amazonian soils differ significantly from the properties of the temperate soils. Most of the soil water release functions implemented in the atmospheric models used in deforestation studies were developed for temperate soils. It is necessary to check the validity of these soil water models with in situ data. In this study, the Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) soil data have been used to modify the parameter values of Clapp and Hornberger's water release model. Different relations between hydraulic parameters and texture are proposed. These relations are included in the ISBA land surface scheme which is used to simulate the long-term evolution of the soil water content and the surface energy balance of three contrasting ABRACOS sites: two pasture sites with distinct soil properties and a forest site. The sensitivity of the simulations to the use of either the original Clapp and Hornberger water release model or the ABRACOS-derived one is shown. [References: 46]