FLOWS - FLOw of Water and Solutes in agricultural and environmental systems

FLOWS is a dynamic model designed for the simulation of water flow and solute transport processes (including nutrients, salts, adsorbed, volatile, or reactive contaminants, etc.) in agro-environmental systems. Among other capabilities, the model provides a physically based prediction of deep percolation fluxes—i.e., water and solute movement beyond the root zone—allowing for the estimation of groundwater recharge and the travel time of potential pollutants (such as nitrates, pesticides, or heavy metals) to the aquifer. A distinctive feature of FLOWS is its client–server architecture, which enables users to interact with the model directly through a web browser, eliminating the need for local installation or configuration. The computational workload is entirely handled by the server, which executes the core MATLAB routines, while the client-side interface offers a streamlined and user-friendly environment for configuring and running simulations. The interface is designed to guide users through the setup process with contextual suggestions and warnings, significantly reducing the likelihood of configuration errors. FLOWS can be used in a "point-scale" configuration, enabling the analysis of flow and transport processes at the local scale (e.g., in cases of localized contamination), or in a "distributed" configuration, which supports multi-site simulations. This functionality is particularly valuable for applications such as irrigation planning and management at the sector or district scale, or for assessing the vulnerability of groundwater resources to diffuse pollution (e.g., from agricultural sources). FLOWS is applicable to a wide variety of agro-environmental scenarios, including the following: Assessment of water, nutrient, and contaminant (e.g., agrochemical) return flows to groundwater and surface water networks; Evaluation of groundwater vulnerability to diffuse agricultural pollution and assessment of the protective capacity of soils; Irrigation management, including the use of non-conventional water sources (e.g., saline or reclaimed water), with optimization of irrigation timing and volumes; Estimation of water requirements and environmental impacts under climate change scenarios; Management of artificial drainage systems; Nutrient and organic matter management through the simulation of chemical transformations and transport of organic and inorganic carbon, nitrogen, and phosphorus, as well as their fluxes within the soil and towards groundwater and surface water bodies; Quantification of CO₂ fluxes within the soil and between the soil and atmosphere; Assessment of ecosystem services provided by soils; Estimation of the impacts of soil degradation processes, such as compaction and erosion As a physically based model, FLOWS is naturally suited for integration into user-defined applications that require the aggregation of information on water and solute fluxes within the soil, as provided by the model.