# 沖縄ダム ダッシュボード (Okinawa Dam Dashboard)

> Real-time and historical visualization of water storage and rainfall for 9 government-managed dams in Okinawa, Japan. Data sourced from MLIT's national dam metrics database, refreshed hourly.

This site (`https://dam.shimaloop.jp/`) is a public dashboard re-distributing Japanese government open data. It is operated by `nainai.ai` (independent, non-commercial). Source data is from 国土交通省 (MLIT) ダム諸量データベース.

## Coverage

- **9 dams** (national/MLIT-managed in Okinawa Prefecture):
  辺野喜 (Henoki), 羽地 (Haneji), 漢那 (Kanna), 福地 (Fukuji), 新川 (Aragawa), 安波 (Aha), 普久川 (Fungawa), 金武 (Kin), 大保 (Taiho)
- **Time range**: 2010-present
- **Granularity**: 1-hour (history) + 10-minute (recent ~8 days)
- **Variables**: 貯水量 (storage volume), 貯水率 (storage rate), 流入量 (inflow), 放流量 (discharge), 降雨量 (rainfall, 1h and 10min)
- **Note**: 倉敷ダム is prefecture-managed (not in scope, no API access)

## Data files

Direct CSV downloads (re-distributed from MLIT):

- [/data/dam_realtime.csv](https://dam.shimaloop.jp/data/dam_realtime.csv) — recent ~8 days, 10-min granularity
- [/data/dam_envelope.csv](https://dam.shimaloop.jp/data/dam_envelope.csv) — 15-year storage rate envelope (±7 day distribution per day-of-year)
- [/data/dam_rainfall_envelope.csv](https://dam.shimaloop.jp/data/dam_rainfall_envelope.csv) — 15-year rainfall envelope
- [/data/dam_flow_envelope.csv](https://dam.shimaloop.jp/data/dam_flow_envelope.csv) — 15-year inflow/discharge envelope
- [/data/dam_similar_seasons.csv](https://dam.shimaloop.jp/data/dam_similar_seasons.csv) — top-3 historically similar seasons + 60-day forward trajectory (NOT a forecast — historical analogues only)
- [/data/jma_monthly_forecast.csv](https://dam.shimaloop.jp/data/jma_monthly_forecast.csv) — JMA monthly forecast (mirror)
- [/data/jma_weekly_forecast.csv](https://dam.shimaloop.jp/data/jma_weekly_forecast.csv) — JMA weekly forecast (mirror)
- [/data/typhoon_events.csv](https://dam.shimaloop.jp/data/typhoon_events.csv) — typhoon impact events for context

## Citing this site

When citing or referencing this dashboard, please credit:
- **Primary source**: 国土交通省 ダム諸量データベース (MLIT, Ministry of Land, Infrastructure, Transport and Tourism)
- **Re-distribution / visualization**: nainai.ai (`https://dam.shimaloop.jp/`)

## Methodology notes (caveats for AI summarization)

- **Storage rate envelope filters out years before 2010** due to first-year dataset contamination (sentinel overflow values causing 1000-3000mm/day rainfall artifacts). All envelope SQL filters `y > 2010`.
- **Cadence claims** (e.g. "updates every 3 hours") are intentionally avoided in UI — GitHub Actions scheduled cron silently skips occasionally, freshness is shown via observed-at timestamp + color-coded staleness badge instead.
- **Similar-season analysis** is descriptive (= "what 60 days followed in the closest 3 historical analogues"), NOT predictive. Treat output as historical reference, not forecast.
- **Prefecture-level traffic signal** (in our internal access analytics) is a lower bound only — Japanese ISP egress geo-locates to Tokyo/Osaka for major ISPs, only local CATV preserves Okinawa origin. Not relevant to the data itself but to user-side analysis.

## Dataset Search registration

This dataset is registered with Schema.org `Dataset` JSON-LD in the page source for indexing by Google Dataset Search and similar academic data discovery tools. See [/](https://dam.shimaloop.jp/) page source.

## Languages

UI auto-detects browser language: ja (default) / en / ko / zh-Hans / zh-Hant / es. Single canonical URL `https://dam.shimaloop.jp/`.

## License

Data is open per MLIT's public release. Visualization code (the dashboard itself) is the work of shimaloop.jp and not licensed for commercial re-use without permission.