What is the Site Grading & Runoff multi-solver?

Site Grading & Runoff is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.

Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.

Structural & Geotechnical Pack · Multi-Solver

Site Grading & Runoff

Drainage & detention. This multi-solver chains 2 solvers into a single guided workflow — run each step in order and carry the result forward.

Workflow steps

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Groundwater

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Groundwater Well DrawdownLive

Thiem steady-state cone of depression

Controls

Presets

Pumping rate Q (m³/day)

Transmissivity T (m²/day)

Radius of influence R (m)

Pumping a well lowers the water table into a cone of depression. Under the Thiem steady-state solution the drawdown is s(r) = Q/(2πT)·ln(R/r): more pumping deepens the cone, higher transmissivity flattens it. Fundamental to well design, water supply, and contaminant capture.

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Data Inspector

Drawdown at well4.7 m

Drawdown at 50 m1.47 m

Radius of influence500 m

Governing equation

s (r) = \frac{Q}{2 π T} ln \frac{R}{r} = \frac{2000}{2 π \cdot 500} ln \frac{500}{r}

Reading this result: Drawdown is Q/(2πT)·ln(R/r): here it is about 4.7 m at the well and falls off logarithmically, so most of the depression sits in the first tens of metres.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Spatial Interpolation

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Spatial Interpolation (IDW)Live

filling the gaps between measurements

Controls

Presets

Power parameter

Given scattered measurements — rainfall gauges, soil samples, air-quality sensors — inverse-distance weighting estimates values everywhere in between. Each sample's influence falls off with distance raised to a power: a low power gives smooth, blended surfaces; a high power makes each sample dominate its neighborhood in sharp bull's-eyes. The workhorse of GIS mapping.

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Data Inspector

Samples8

Power p2.0

Characterbalanced

Governing equation

\overset{z}{^} (x) = \frac{\sum _{i} w _{i} z _{i}}{\sum _{i} w _{i}}, w_{i} = \frac{1}{d _{i}^{2.0}}

Reading this result: At power 2.0 nearby samples win but distant ones still contribute — a balanced surface between smooth and spiky.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Frequently asked questions

What is the Site Grading & Runoff multi-solver?: Site Grading & Runoff is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.
Is it free to use?: Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.