The conceptual framework of reactive nitrogen calculation module integration in conceptual hydrological model METQ

Effective nitrogen management is critical for addressing global challenges such as climate change, water pollution, and sustainable ecosystem management. The METQ conceptual hydrological model, widely used for water resource analysis, has been extended to include reactive nitrogen transformation calculations. This study focuses on integrating nitrogen dynamics into METQ, leveraging its modular framework to simulate nitrogen fluxes across surface, subsurface, and groundwater systems, with an emphasis on the local Latvian environment. The reactive nitrogen module utilizes hydrological outputs from METQ as boundary conditions for nitrogen simulations. Nitrogen transport through surface runoff was calculated using flow rates and nitrogen concentrations in the upper soil layers. Subsurface nitrogen movement was modelled within shallow and deep drainage pathways, incorporating lateral and vertical flow dynamics. Additionally, leached nitrogen was routed to the groundwater compartment, where delayed outflow to surface water bodies was accounted for, ensuring a comprehensive representation of nitrogen fluxes across hydrological systems. Key datasets, including farm management, meteorological, and soil data, were integrated into the model. Algorithmic blocks simulate nitrogen inputs, transformations, and transport, dynamically coupling with METQ’s hydrological outputs. The integration of nitrogen transformation calculations was found to significantly enhance METQ’s capability to assess nitrogen pollution and its associated environmental impacts. Modular reprogramming of METQ was shown to enable seamless addition of functionalities, improving computational efficiency and fostering interdisciplinary research. The extended METQ model facilitates comprehensive analysis of interactions among soil, water, and atmosphere, positioning it as a valuable tool for ecosystem and sustainability studies. The advancements in METQ position it as a cutting-edge tool for environmental impact analysis, including nitrogen emissions, nutrient cycling, and sediment transport. By adopting a modular, open-framework design, METQ fosters innovation and collaboration within the scientific community. These enhancements support global environmental goals, such as climate change mitigation and sustainable water resource management.