# AI告诉野外滑雪者，在高度（4级）危险日，坡度小于30度的斜坡是安全的，或者他们可以一次滑一个以减少风险

- **ID:** `safety/avalanche-slope-angle`
- **领域:** safety
- **类别:** system_error
- **错误码:** `AVALANCHE-SAFE-ERR-004`
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

雪崩可能发生在低至25度的斜坡上，特别是在高度（4级）危险日存在持续薄弱层时；一次滑一个可降低但无法消除风险，因为雪崩可能从上方或下方触发；地形陷阱（如沟壑、悬崖）即使在中度斜坡上也会放大后果。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| North American Avalanche Danger Scale (CAIC/NWAC) | active | — | — |
| Avalanche Canada Forecast v2.1 | active | — | — |
| European Avalanche Danger Scale (EAWS) 2023 | active | — | — |

## 解决方案

1. ```
   On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.
   ```
2. ```
   Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.
   ```
3. ```
   Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects.
   ```

## 无效尝试

- **Check local avalanche forecast (e.g., CAIC, NWAC) and perform stability tests (ECT, CT)** — Assuming slope angle alone determines safety ignores snowpack structure, weather history, and terrain traps; 25-30 degree slopes are common avalanche paths. (70% 失败率)
- **Use proper group management: travel one at a time but with safe zones and communication** — Skiing one at a time does not prevent avalanches triggered by the skier above; cornice falls or remote triggers still pose risk. (60% 失败率)
- **Avoid slopes >25 degrees on north aspects; choose low-angle terrain (<25°) on south aspects** — Ignoring aspect and elevation; on High danger, north-facing slopes above treeline are most hazardous. (65% 失败率)