Hydrology Simulations

A collection of interactive 3D visualizations and simulations to help you master concepts in hydrology.

Introduction to Hydrology - Theory & Concepts

Understanding the Hydrologic Cycle, Water Balance, and Meteorological Data.

Water Balance Simulator

Precipitation (P)100 mm

Evapotranspiration (ET)40 mm

Groundwater Flow (G)20 mm

Resulting Runoff (R)

40 mm

Assuming $\Delta S = 0$

Equation:R = P - ET - G

Calculation:40 = 100 - 40 - 20

Precipitation - Theory & Concepts

Forms, measurement, and analysis of precipitation data.

Areal Precipitation Methods

Compare different methods for estimating average precipitation over a catchment area. Drag the rain gauges (dots) to change their locations, and adjust their rainfall values below.

Calculated Average:0.00 mm

Gauge Stations

Station 150 mm

Station 230 mm

Station 380 mm

Station 445 mm

Thiessen Polygon: Assigns an area of influence to each gauge based on perpendicular bisectors. The average is area-weighted.

Hydrologic Losses - Theory & Concepts

Understanding Evaporation, Transpiration, and Infiltration.

Evaporation Rate Simulator

Adjust the environmental variables to see how they impact the daily evaporation rate.

Mean Daily Temp (°C): 25

Relative Humidity (%): 50

Wind Speed (km/h): 10

Peak Solar Radiation (W/m²): 500

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Streamflow Measurement - Theory & Concepts

Techniques for measuring stage and discharge in rivers and streams.

Velocity-Area Method Simulation

Number of Segments: 5

Total Discharge (Q)12.50 m³/s

Stream Cross-Section View

Q: 0.30 m³/s

Q: 1.00 m³/s

Q: 2.10 m³/s

Q: 3.60 m³/s

Q: 5.50 m³/s

0m10.0m

Segment	Width (m)	Depth (m)	Velocity (m/s)	Q (m³/s)
1				0.30
2				1.00
3				2.10
4				3.60
5				5.50
Total Discharge (Q) =				12.50

Runoff - Theory & Concepts

Catchment characteristics, runoff components, and the Rational Method.

Hydrograph Components Simulator

Adjust the multipliers to see how Overland Flow, Interflow, and Baseflow contribute to the total stream discharge over time. Notice the different response times and durations for each component.

Overland Flow (Surface Runoff)

Interflow (Subsurface Stormflow)

Baseflow (Groundwater Runoff)

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Hydrographs - Theory & Concepts

Analysis of streamflow over time, Unit Hydrographs, and Baseflow Separation.

Baseflow Separation Methods

Select a separation method to isolate the Direct Runoff Hydrograph (DRH) from the Baseflow.

Straight Line MethodFixed Base MethodVariable Slope Method

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Straight Line Method:Connects the start of the rising limb directly to the point on the recession limb where direct runoff is assumed to end. It's the simplest method but least physically accurate.

Flood Routing - Theory & Concepts

Muskingum Method and Reservoir Routing.

Muskingum Channel Routing Simulation

Adjust the Storage Time Constant (K) and Weighting Factor (x) to see how the flood wave is attenuated and delayed.

K (Storage Constant): 12 hours

x (Weighting Factor): 0.2

Δt (Time Step): 6 hours

C0: 0.0476

C1: 0.4286

C2: 0.5238

ΣC: 1

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Groundwater Hydrology - Theory & Concepts

Aquifers, Darcy's Law, and Well Hydraulics.

Darcy's Law Groundwater Flow Simulator

Adjust aquifer parameters to see the hydraulic head profile and calculate the steady-state discharge $Q$ .

Conductivity K (m/d): 10

Upstream Head h₁ (m): 50

Downstream h₂ (m): 45

Length L (m): 100

Area A (m²): 100

Hydraulic Gradient (i)

0.0500

Discharge (Q)

50.00 m³/day

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Statistical Hydrology - Theory & Concepts

Return Period, Probability, and Frequency Analysis.

Risk and Reliability Calculator

Explore the relationship between Return Period ( $T$ ), Annual Exceedance Probability ( $P$ ), and the total Risk over a project's design life ( $n$ ).

Return Period (

T

) in years: 100 yr

P = 1/100 = 1.00% chance of occurring in any single year.

Project Design Life (

n

) in years: 50 yr

Total lifetime risk of the event occurring at least once: 39.50%.

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Urban Hydrology - Theory & Concepts

Effects of Urbanization and Stormwater Management.

Impact of Urbanization Simulator

Adjust the level of imperviousness (urban development) to see how it alters the hydrograph compared to the pre-development (rural) state.

Impervious Cover (Concrete, Asphalt, Roofs)0%

Rural (0%)Suburban (~30%)Dense Urban (100%)

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Peak DischargeIncreases as water runs off instantly instead of infiltrating.

Time to Peak (Lag Time)Decreases due to hydraulic efficiency (sewers, gutters).

Snow Hydrology - Theory & Concepts

Understanding snow accumulation, Snow Water Equivalent (SWE), and snowmelt modeling.

Degree-Day Snowmelt Simulation

Daily Air Temperature (

T_a

): 5°C

Melt Coefficient (

C_M

): 3 cm/°C·day

Initial Snow Depth (

d_s

): 100 cm

Snow Density (

\rho_s

): 300 kg/m³

SWE = d_s \times \frac{\rho_s}{\rho_w}

M = 15.0 \text{ cm/day}