A component based modular treatment of the soil-plant-atmosphere continuum: the GEOSPACE framework (v.1.2.9)

Abstract. The soil-plant-atmosphere continuum (SPAC) system is a complex and interconnected network of physical phenomena, encompassing heat transfer, evapotranspiration, precipitation, water absorption, soil water flow, substance transport, and gas exchange. These processes govern the exchange of energy, matter, and water within the SPAC system. To better understand and model SPAC interactions, interdisciplinary approaches are essential due to the inherent complexity of the system. Instead of relying on a single monolithic model, we propose a component-based modeling approach, where each component addresses a specific aspect of the system. Object-oriented programming (OOP) is adopted as the foundational framework for this approach, providing flexibility and adaptability to accommodate the ever-changing nature of the SPAC system.

The Soil Plant Atmosphere Continuum Estimator in GEOframe (GEOSPACE) is presented in this paper, in particular the one-dimensional development, GEOSPACE-1D. The framework is a tool designed to facilitate robust, reliable and transparent simulations of SPAC interactions. It embraces the principles of open-source software and modular design, aiming to promote open, reusable, and reproducible research practices. By implementing the OOP, GEOSPACE-1D breaks down the complexity of SPAC modeling into smaller, self-contained structures, each responsible for a specific scientific or mathematical concept. This modular architecture adheres to the "open to extensions, closed to modifications" philosophy, enabling easy model extension without disrupting existing components. Equations are implemented in an abstract manner, emphasizing the use of common interfaces over concrete classes, a hallmark of contemporary OOP. GEOSPACE-1D adopts a generic programming framework, where distinct classes adhere to a common interface. This compartmentalization serves two critical purposes: validating individual processes against analytical solutions and facilitating the integration of novel processes into the system.

The paper emphasizes the significance of modeling the coupling between infiltration and evapotranspiration for accurate hydrological simulations. It explores the interplay between plant transpiration, soil evaporation, and soil moisture dynamics, highlighting the need to account for these interactions in SPAC models. The paper concludes by underlining the importance of modularity, transparency, and openness in SPAC modeling, principles that underlie the development of GEOSPACE-1D and its components. Overall, GEOSPACE-1D represents a promising approach to SPAC modeling, providing a flexible and extensible framework for studying complex interactions within the Earth's Critical Zone. It is worth recalling that the fundamental premise of GEOSPACE-1D is not to create a single soil-plant-atmosphere model, but to establish a system that allows the creation of a series of soil-plant-atmosphere models, adapted to the specific needs of the user's case study.