Orchard Row Shade Simulator

Q: "Is slope aspect alone enough?"

"Aspect alone does not tell you slope steepness, so the settings use a reference slope angle."

Q: "Can I use it in the Southern Hemisphere?"

"Yes. The latitude sign switches hemispheres, and the same true-north azimuth convention is used."

Q: "Do I need true north?"

"Yes. Row direction and slope aspect are true-north based. Convert magnetic bearings first if needed."

Q: "What if I do not know row spacing?"

"Auto mode uses 1.5× canopy width as the default and estimates cross-row overlap."

Q: "Can I use it outside orchards?"

"Yes. The same logic works for vineyards and other row-based perennial systems."

Visualize which side of a row orchard gets more shade from latitude, slope aspect, row direction, tree height, and canopy width.

It runs entirely in the browser and lets you switch between annual bias and representative sun conditions.

True north In-browser calculation Hemisphere-aware Share URL

What This Tool Shows

See which side the shade tends to drift toward when you change the row direction.

See how slope aspect and slope steepness affect uphill/downhill bias in the same view.

Check how far the shadow reaches relative to row spacing with one clear ratio.

How to Use

Enter latitude, slope aspect, and row direction.
Enter tree height and canopy width.
Open settings only if you want to refine slope angle and row spacing.
Review the result card and heatmap to inspect shade bias.

Examples

Typical Orchard in the Northern Hemisphere

Input

Latitude 35.7°, slope aspect 180°, row direction 0°, tree height 3.2m, canopy width 2.8m, mode Annual

Output

Annual bias leans slightly downhill, and low sun increases cross-row overlap.

Row Orchard in the Southern Hemisphere

Input

Latitude -34.6°, slope aspect 20°, row direction 90°, tree height 4.0m, canopy width 3.4m, mode Low Sun

Output

The same true-north convention works in the Southern Hemisphere. Low sun increases downhill bias.

Glossary

True north

The north reference used for maps and azimuths. It is not always the same as magnetic north.

Azimuth

Angle measured clockwise from north. It lets the simulator treat row direction and slope aspect consistently.

Aspect

The downhill-facing direction of a slope. It affects uphill/downhill shade bias.

Shade Bias Index

A percentage-style index for uphill/downhill shade bias. Values near zero mean a more balanced result.

Cross-Row Reach

The ratio of shadow reach to row spacing. Values above 1 suggest row overlap.

Formulas

Solar altitude: sin α = sin φ sin δ + cos φ cos δ cos H
Azimuth: A = normalize(atan2(sin H, cos H sin φ - tan δ cos φ))
Terrain normal: n = normalize([sinβ sinAs, sinβ cosAs, cosβ])
Shadow tip: S = P + t(-u), t = -n·P / n·(-u)
Shade bias index: 100 × (downhill - uphill) / total shade
Cross-row reach: shadow width perpendicular to the row / row spacing

Frequently Asked Questions

Is slope aspect alone enough?

Aspect alone does not tell you slope steepness, so the settings use a reference slope angle.

Can I use it in the Southern Hemisphere?

Yes. The latitude sign switches hemispheres, and the same true-north azimuth convention is used.

Do I need true north?

Yes. Row direction and slope aspect are true-north based. Convert magnetic bearings first if needed.

What if I do not know row spacing?

Auto mode uses 1.5× canopy width as the default and estimates cross-row overlap.

Can I use it outside orchards?

Yes. The same logic works for vineyards and other row-based perennial systems.

Notes

This tool visualizes geometric bias. It does not guarantee microclimate or yield outcomes.
Actual shade changes a lot with row spacing, canopy shape, pruning, and surrounding terrain.
Enter row direction and slope aspect using true north. Convert magnetic bearings first if needed.
When slope angle is not entered, the tool uses a default reference value. Replace it with a measured value in settings if available.