This simulator follows water between four stores - ocean, atmosphere, surface catchment and groundwater. Change the evaporation, precipitation, infiltration and runoff coefficients and watch each store fill or drain while the total amount of water stays fixed.
• A real-time 3D scene with 4 inspectable parts (Ocean and evaporation, Atmosphere and cloud, Catchment and stream and Subsurface store), with home view, focus-selected-part, auto-rotate, expand, instrument-cover and hide-labels scene tools, plus a model response curve beneath the scene. • Experiment controls: Ocean evaporation coefficient (0.002-0.03 s⁻¹); Atmospheric precipitation coefficient (0.02-0.2 s⁻¹); Land infiltration coefficient (0.005-0.08 s⁻¹); Surface runoff coefficient (0.005-0.08 s⁻¹); show explanatory motion markers; pause/resume, 0.1 s and 1 s single-step buttons, four playback speeds and a restart button. • A Curves & measurements tab with a parameter-comparison chart, a live-measurements chart, the model equations and snapshot readouts (Ocean storage; Atmosphere storage; Surface storage; Groundwater storage; Total modeled water). • An Experiments tab with 2 guided presets (fast rainout and high infiltration) and a Model verification bench that runs independent fresh models, plus a timestamped event log and a copyable trial report. • A Learn & assess tab with guided lessons, a knowledge-check quiz with reset and a written model-scope statement linking to a technical reference.
Evaporation moves water from the ocean to the atmosphere at rate ke times ocean storage; precipitation moves it from the atmosphere to the catchment at kp times atmospheric storage; the catchment loses water to infiltration and runoff at ki and kr times surface storage; and groundwater returns to the ocean as baseflow at 0.015 times groundwater storage.
The four storages always sum to 1,000 units, and the lab shows each store and the total so you can check conservation directly.
Evaporation does not destroy water; it moves water between reservoirs and physical states, so a closed system keeps a constant total. Raising precipitation or infiltration shifts water between stores and changes their time scales.
The model has four well-mixed compartments with first-order rates, so it does not forecast weather or include soil capacity, ice storage or spatial rainfall. Model seconds and storage units are explanatory, and the numerical transfers conserve water and stay nonnegative.
No. It moves water from the ocean to the atmosphere and changes its physical state. In this closed model the total of all four stores is always 1,000 units.
Stay constant. Precipitation, infiltration and runoff transfer water that is already in the system, which the total-water readout confirms.
The first-order coefficients for ocean evaporation, atmospheric precipitation, land infiltration and surface runoff. A higher coefficient moves water out of its source store faster.
No. It is a teaching model with well-mixed stores and no spatial rainfall, soil capacity or ice storage, and it makes no prediction for any real watershed.