# 📐 L2 Spec — Shallow Water Equations — coastal/tidal/inundation Mismatch-Only Spec
**ID:** `L2-181-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-181`](/artifact/l1/L1-181)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41553970
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 64 – 4096 |
| W | px | 64 – 4096 |
| Snr db | dB | 0 – 40 |
| N times | — | 100 – 1000000 |
| Friction error | — | 0.0 – 0.3 |
| Bathymetry error | — | 0.0 – 0.1 |
| Wind forcing error | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
17.0 + 0.3*SNR_dB - 30.0*bathymetry_error - 8.0*friction_error - 10.0*wind_forcing_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`214449fb28dac03ddf6263994a6b50279e0b0f84b2f6ed84695bc7c836a460f9`
## 5. On-chain Registration
- **Chain hash:** `0xe67d8467df6a3b6d017e6cf76cb49a23a9c7c6218e72fbac973c99a3bcec0a65`
- **Chain tx hash:** `0xacca13de5c9f3a5910b5c7a51cc5789e0d2d0874b07391cbe37abafb89eb9362`
- **Chain block:** `41553970`
---
## File Mapping
This bundle consists of: `L2-181-001.md`, `L2-181-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-181-001.md` | Source of truth — edit this | Human or LLM |
| `L2-181-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-181-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._