Downscaling land use and land cover from the Global Change Assessment Model for coupling with Earth system models
The Global Change Assessment Model (GCAM) is a global integrated assessment model used to project future societal and environmental scenarios, based on economic modeling and on a detailed representation of food and energy production systems. The terrestrial module in GCAM represents agricultural act...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-09-01
|
| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/9/3055/2016/gmd-9-3055-2016.pdf |
| Summary: | The Global Change Assessment Model (GCAM) is a global integrated assessment
model used to project future societal and environmental scenarios, based on
economic modeling and on a detailed representation of food and energy
production systems. The terrestrial module in GCAM represents agricultural
activities and ecosystems dynamics at the subregional scale, and must be
downscaled to be used for impact assessments in gridded models (e.g., climate
models). In this study, we present the downscaling algorithm of the GCAM
model, which generates gridded time series of global land use and land cover
(LULC) from any GCAM scenario. The downscaling is based on a number of
user-defined rules and drivers, including transition priorities (e.g., crop
expansion preferentially into grasslands rather than forests) and spatial
constraints (e.g., nutrient availability). The default parameterization is
evaluated using historical LULC change data, and a sensitivity experiment
provides insights on the most critical parameters and how their influence
changes regionally and in time. Finally, a reference scenario and a climate
mitigation scenario are downscaled to illustrate the gridded land use
outcomes of different policies on agricultural expansion and forest
management. Several features of the downscaling can be modified by providing
new input data or changing the parameterization, without any edits to the
code. Those features include spatial resolution as well as the number and
type of land classes being downscaled, thereby providing flexibility to
adapt GCAM LULC scenarios to the requirements of a wide range of models and
applications. The downscaling system is version controlled and freely
available. |
|---|---|
| ISSN: | 1991-959X 1991-9603 |