Shoaling coefficient
shoaling_coefficient
Shoaling coefficient K_s (dimensionless)
Scores if within ±3% of the reference value.
Transforms deep-water wave height to nearshore conditions by computing shoaling coefficient K_s and refraction coefficient K_r, yielding H = H_0 * K_s * K_r. Uses the Fenton and McKee (1990) explicit dispersion relation approximation to avoid iterative wavelength solutions, and applies Snell's law for wave angle refraction per the USACE Coastal Engineering Manual.
both: The model must reason numerically unaided.
One template produces many comparable benchmark tasks while keeping the scoring contract fixed.
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The reusable contract shown on this page.
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An archetype and site context are sampled.
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Inputs may be hidden at harder tiers.
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The model responds with the declared outputs.
Inputs the model receives, and the outputs it is scored on.
4 inputs
Included directly in every task prompt.
Deep water wave height
deep_water_wave_height_m
Deep-water significant wave height H_0
Nearshore depth
nearshore_depth_m
Water depth at the nearshore location d
Sampled from the scenario and inferable from its description.
Wave period
wave_period_s
Wave period T
Derived from the archetype scenario. Hidden at hard difficulty.
Deep water wave angle deg
deep_water_wave_angle_deg
Deep-water wave crest angle to bottom contour theta_0
Derived from the archetype scenario. Hidden at hard difficulty.
3 outputs
shoaling_coefficient
Shoaling coefficient K_s (dimensionless)
Scores if within ±3% of the reference value.
refraction_coefficient
Refraction coefficient K_r (dimensionless)
Scores if within ±3% of the reference value.
nearshore_wave_height_m
Nearshore wave height H (m)
Scores if within ±5% of the reference value.
Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.
All inputs given
Normal incidence with moderate depth — all parameters given, straightforward calculation
All inputs given
Oblique approach or reef shelf — all parameters given, refraction effects significant
Some inputs hidden
Wave period and approach angle hidden — agent must infer from site description
Hidden inputs
Prompt replacement text
The site is {{ archetype.description }} ({{ archetype.site_context }})
The exact instruction and parameter contract used to generate this task, pinned to the published library source.
/workspace
Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.
1You are a senior coastal engineer specializing in wave mechanics and nearshore transformations.2 3## Problem4 5Determine the wave transformation from deep to shallow water at a coastal site. Calculate the shoaling coefficient, refraction coefficient, and the resulting nearshore wave height.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Deep-water wave height (H₀) | {{ deep_water_wave_height_m }} | m |12{% if wave_period_s is defined %}13| Wave period (T) | {{ wave_period_s }} | s |14{% endif %}15| Nearshore depth (d) | {{ nearshore_depth_m }} | m |16{% if deep_water_wave_angle_deg is defined %}17| Deep-water wave angle to contour (θ₀) | {{ deep_water_wave_angle_deg }} | degrees |18{% endif %}19{% if archetype_description is defined %}20 21### Site Conditions22 23{{ archetype_description }}24{% endif %}25 26{% if tool_available %}27## Available Tool28 29A wave shoaling calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:30 31```bash32python3 /workspace/{{ meta.name }}_calc.py --help33```34 35You may use this tool to verify your calculations or compute values directly.36{% endif %}37 38## Required39 40Calculate the following:41 421. Shoaling coefficient K_s (dimensionless)432. Refraction coefficient K_r (dimensionless)443. Nearshore wave height H (m)45 46## Applicable Standards47 48- USACE Coastal Engineering Manual (CEM)49- Fenton & McKee (1990) explicit wavelength approximation50 51## Constraints52 53- No internet access is available. Work from engineering knowledge and the provided tool.54- Use the following procedure:55 1. **Deep-water wavelength**:56 - L₀ = g × T² / (2π)57 - where g = 9.81 m/s²58 2. **Local wavelength** via Fenton & McKee (1990) explicit approximation:59 - σ = 2π / T60 - kd = (σ² × d / g) × [coth((σ² × d / g)^(3/4))]^(2/3)61 - where coth(x) = 1 / tanh(x)62 - k = kd / d, L = 2π / k63 - This avoids iterative solution of the dispersion relation (< 1.5% error).64 3. **Phase and group velocity**:65 - C = L / T (local phase celerity)66 - n = 0.5 × (1 + 2kd / sinh(2kd))67 - C_g = n × C (local group velocity)68 4. **Deep-water group velocity**:69 - C_g0 = g × T / (4π)70 5. **Shoaling coefficient**:71 - K_s = √(C_g0 / C_g)72 6. **Refraction** via Snell's law:73 - C₀ = L₀ / T (deep-water phase celerity)74 - sin(θ) / C = sin(θ₀) / C₀75 - K_r = √(cos(θ₀) / cos(θ))76 7. **Nearshore wave height**:77 - H = H₀ × K_s × K_r78 79## Output Format80 81Show your step-by-step working in Markdown. At the end of your solution, include a JSON block with your final answers in exactly this format:82 83```json84{85 "shoaling_coefficient": <numeric_value>,86 "refraction_coefficient": <numeric_value>,87 "nearshore_wave_height_m": <numeric_value>88}89```90 91Write your complete solution to `/workspace/output.md`.92 Each generated task is drawn from one of these realistic scenario bands.
Site contexts ground each scenario in a real locale the model can use to infer hidden values.
open_coast_normal
Open coast with waves arriving nearly perpendicular to shoreline
oblique_approach
Coast with waves arriving at a significant oblique angle
sheltered_bay
Semi-enclosed bay with reduced wave energy and moderate refraction
reef_shelf
Shallow reef platform with rapid depth transition and strong refraction
gold-coast-open-beach-open-coast-normal-preview — hard difficulty, some inputs hidden.
Open coast with waves arriving nearly perpendicular to shoreline. gold-coast-open-beach. Required outputs: shoaling_coefficient, refraction_coefficient, nearshore_wave_height_m
Scenario context and visible inputs.
Executable tool: wave-shoaling_calc.py
Inputs withheld at this difficulty.
Wave period s
wave_period_s
Deep water wave angle deg
deep_water_wave_angle_deg
Stand-in text in the prompt
The site is {{ archetype.description }} ({{ archetype.site_context }})
The scored JSON answer schema.
{
"shoaling_coefficient": <number>,
"refraction_coefficient": <number>,
"nearshore_wave_height_m": <number>
}