During the last decades, humans have changed the land surface more rapidly and extensively than they have done in any period before. Both anthropogenic impact and climate variations have led to changes in vegetation and land cover. These changes also alter biogeophysical properties of the land surface such as albedo, Leaf Area Index (LAI) and surface roughness and can thus significantly influence climate at regional and local scales. The interactions between land surface and climate are thus of high relevance for understanding the coupled Social-Ecological-System (SES). In order to consider and understand the influence that land surface properties exert on regional climate, land surface characteristics need to be considered adequately in climate modeling approaches.
The aim of this Work Package is to contribute to a profound understanding of the impact of land surface and land surface changes on the exogenous controlling factor climate. In this context, the regulating ecosystem service potential of current and historic land cover as well as associated land surface characteristics on climate will be assessed and quantified. For this purpose, the historical profile of land surface properties, i.e. the current and historic spatiotemporal patterns of selected Terrestrial Essential Climate Variables (ECV’S) will be derived by remote sensing. These variables will include e.g. LAI, green vegetation cover, albedo, water surface extent and land cover.
Based on the historical profile of these variables, the impact of land cover changes on the components of the regional climate and its feedback can be analyzed using the dynamic component of the regional climate modeling system established in WP 1.1 Statistical techniques for upscaling land surface information will be developed and incorporated into the regional climate modeling system to replace the standard schemes used for the assimilation of the land surface information. The land surface information of different land use intensities in the watersheds will be incorporated into the atmospheric model. Finally, simulation in a climate mode over a recent period will be performed to study the impact of land surface changes on climate variables such as precipitation or evaporation.
Understanding this feedback system forms a basic component of all research activities in WASCAL: it enables an improved modeling of current and past climate (i.e. the historical profile of climate) and it is the only way to consider the feedback effect of land use and land cover scenarios in climate simulations. Without these analyses, the effects on adapted land use management may lead to undesirable results in the future. Finally, the modeling activities will be presented in workshops and training courses will be given to transfer the techniques developed in this WP to practice and to establish these novel techniques at the Competence Center.