MAgPIE 4 – A modular open source framework for modeling global land-systems

Abstract

Abstract. The open source modeling framework MAgPIE combines economic and biophysical approaches to simulate spatially-explicit global scenarios of landuse within the 21st century and the respective interactions with the environment. Besides various other projects, it was used to simulate marker scenarios of the Shared Socio-economic Pathways (SSPs) and contributed substantially to multiple IPCC assessments. However, with growing scope and detail, the non-linear model has become increasingly complex, computational intensive, and intransparent, requiring structured approaches to improve the development and evaluation of the model. Here we provide an overview on version 4 of MAgPIE, and how it addresses these issues of increasing complexity using new technical features: modular structure, flexible detail in process dynamics, flexible spatial resolution, in-code documentation, automatized code-checking, model/output evaluation, and open accessibility. Application examples provide insights into model evaluation and region-specific analysis approaches. While this paper is focused on the general framework as such, the publication is accompanied by a detailed model documentation describing contents and equations, and by model evaluation documents giving insights into model performance for a broad range of variables. With the open source release of the MAgPIE 4 framework we hope to contribute to more transparent, reproducible and collaborative research in the field. Due to its modularity and spatial flexibility it should provide a basis for a broad range of land-related research with economic or biophysical, global or regional focus.

MAgPIE 4 – a modular open-source framework for modeling global land systems

“…The release (version 4) used in this paper can be found via Zenodo (https://doi.org/10.5281/zenodo.1445533, Dietrich et al, 2018e). The technical model documentation is available under https://rse.pik-potsdam.de/doc/magpie/version4/ (last access: 15 March 2019) and also archived via Zenodo (https://doi.org/10.5281/zenodo.1471526, Dietrich et al, 2018d). Test runs shown in this paper are archived at https://doi.org/10.5281/zenodo.2572620 (Dietrich, 2019a) and corresponding evaluation documents can be found at https://doi.org/10.5281/zenodo.2572581 (Dietrich, 2019b).…”

“…The MAgPIE 4 framework consists of 38 modules which are listed and briefly described below (by name and order as they appear in the code). A detailed description of each module and their realizations is part of the model documentation (Dietrich et al, 2018d). While some modules come with several realizations that are regularly exchanged for simulation runs, others remained mostly unchanged over time.…”

“…Therefore, the figure only shows the most important linkages and modules or module groups in terms of relevance to the framework or representation of the underlying concept. An exact representation of all interfaces and modules can be found in the technical model documentation (Dietrich et al, 2018d). If modules are not directly linked, it does not mean that they do not interact with each other.…”

“…By merging code and documentation text into one document, the likelihood of outof-sync code and documentation is reduced. The final MAg-PIE 4 model documentation can be found online (Dietrich et al, 2018d).…”

“…MAgPIE 4 framework with simplified modular structure and module interactions. See the model documentation(Dietrich et al, 2018d) for a more detailed presentation of module interactions and their implementations.…”