Model Types by Representation

• Lumped conceptual models represent water-related systems through global storage entities (e.g., surface water, aquifer storage) and follow principles like continuity, but lack a complete description of driving forces (e.g., rainfall-runoff models).
• Physically-based, distributed models provide a detailed description of the physical phenomena, applying principles like mass conservation and momentum, and are used for flow in porous media (e.g., Darcy's and Richards' equations).
• Data-driven models focus on correlating input and output data without analyzing underlying phenomena, requiring significant prior knowledge and data observations (e.g., linear regression, unit hydrograph).