OTIS is a mathematical simulation model used to characterize the fate and transport of waterborne solutes in streams and rivers. OTIS is often used with data from field-scale tracer experiments to quantify the hydro-logic parameters affecting solute transport. Additional applications include analyses of non-conservative solutes that are subject to sorption processes and/or first-order decay. The governing equation underlying the model is the advection-dispersion equation with additional terms to account for transient storage, lateral inflow, first-order decay, and sorption. This equation and the associated equations describing transient storage and sorption are solved using a Crank-Nicolson finite-difference solution.
Description: OTIS.pdf Website: https://water.usgs.gov/software/OTIS/
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