Title Rawan River

  • Hokkaido
Topic(s):
$SETTINGS_DB.genreMap.get($item) Public Works & Institutions (Museums, etc.) National Parks/Quasi-National Parks
Medium/Media of Use:
Interpretive Sign App, QR code, etc.
Text Length:
≤250 Words
FY Prepared:
2018
Associated Tourism Board:
Akan-Mashu National Park

螺湾川


概要


螺湾川はオンネトーの唯一の流出河川であり、オンネトーから輝くような青色の水を国立公園外に運んでいます。足寄市街地で足寄川へと接続したあと最終的には十勝川に合流し、太平洋へと流れ込みます。上流部の周辺は原生的な森林帯で川底にはハゼなどの魚も観察できます。この川の最大の特徴は、なんといっても流域で自生するラワンブキです。螺湾川の綺麗な水に育まれたラワンブキは高さ2~3mにも達し、北海道遺産に指定されています。このラワンブキは、6月から7月にかけて、国立公園外の鑑賞ほ場で見ることができます。


ラワンブキについて


ラワンブキはアキタブキの1種と考えられていますが、何故これほど巨大に育つかについては分かっていません。以前より食用として採集されており、流域にある自生地は減少しましたが、現在は農家がほ場で栽培したものが出荷され、足寄町の特産品となっています。

Rawan River


Overview


The Rawan River is the only river flowing out of Lake Onneto. It carries the blue waters of the lake out of the national park toward the town of Ashoro, connecting with the Ashoro River before finally joining the Tokachi River and continuing on to the Pacific Ocean. The upper section of the Rawan River is surrounded by a primeval forest zone, where fish such as gobies can be seen on the riverbed. The river is known for its Rawan-buki (Petasites japonicus), a giant variety of Japanese butterbur that flourishes in the river basin. In the clear waters of the Rawan River, they can reach astonishing heights of two to three meters and have been designated a “Hokkaido Heritage.” The best time to see Rawan-buki is between June and July, in the farmland surrounding Akan-Mashu National Park.


The Rawan-buki


The reason Rawan-buki grow so high here remains unknown. An edible plant, they were heavily harvested in the past. The number of wild Rawan-buki colonies found within the river basin has decreased significantly, so they are also cultivated on farms and exported as a specialty of Ashoro Town.

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