SP 4 - Consequences of land use changes for the water and matter balance

This subproject focuses on the GHG emissions and matter balances under climate and land use change and allows for the evaluation of the contribution of land use change to the GHG emission reduction goals in Germany. The subproject supports the answer of research questions related to the adaptation of land management and the trade-offs between carbon optimised land management and societal needs regarding biomass production from agriculture and forestry.

Potsdam-Institute Climate Impact Research (PIK)

Aims:

The subproject will determine the changes in the land-wide water, carbon and nitrogen household of Germany’s river basins due to land use and climate change. The investigations will be carried out for current and possible alternative land use schemes combined with the current climate and scenarios for the anticipated climate change. The assessment will be based on a modelling system consisting of the statistical climate model STAR, the eco-hydrological model SWIM and the forest model 4C (http://www.pik-potsdam.de/~lasch/4c.htm). The subproject contributes mainly to the Module M “Integrated Modelling” of CCLandStrad.

Research approach and methods:

The subproject delivers regionalised climate data and projections of climate scenarios on the basis of the IPCC-Assessment Report 4 GCM data using the statistical climate model STAR 2.0 and generates climate change scenarios adjusted according to stakeholder requirements and input from the GLUES project.

Modelling of the interaction between atmospheric CO2 concentration, climate and nitrogen deposition is done with a model chain consisting of the ecohydrological model SWIM and the forest dynamics model 4C. The model chain will follow the pool and flow dynamics of idealised soil-plant-atmosphere systems of the major landscapes in a daily mode for a transient climate period from 1960 up to 2060.  The models are validated using monitoring data, satellite scenes, temperature measurements and outlet gauge data of river basins. The simulation results for water, carbon and nitrogen characteristics of agriculture and forestry are aggregated to higher administrative and landscape units, to the time slices 1960-2008, 2011-2030, and 2031-2060. The conceptual coupling of the SWIM-4C simulations with GHG emission modules and the preparation of modelling results for focus regions, GLUES and the integrated assessment are intended.