We went to a field survey of rivers and coasts in northern Okinawa.

3/19 2021

We visited several locations in Okinawa Prefecture. These places were the Genka River, Taiho Dam, Fukuji Dam, Taira Beach, Gesashi River, and Sukubama. Our trip was very interesting and rewarding.

First, we arrived at the river mouth of the Genka river and watched from the bridge.

Then we went to the gravel-bed section of the Genka river and went down to the river bed.

We could see riffles and pools where flow configuration changed between the subcritical flow and the super critical flow.

We were able to see the inbrication structure on the river-bed surface

Next place was Taiho Dam. Taiho Dam is located at the upstream of Shiyoa Bay Ogimi Village in the north of mainland Okinawa. The height is 77.5 m., the crest length is 363.3 m., and reservoir capacity is 200,50 thousand ton. Taiho Dam is the second largest dam in Okinawa.

Taiho Dam (Side dam)

Fukuji Dam

The Fukuji Dam was a stone dam. The purpose of the dam was water supply and flood control. We learned that under the direction of the Ryukyu Domestic water Corporation, the US Army Corps Engineers began construction of the dam in 1969. The dam was completed in 1991 by the Japanese government.

Taira Beach

The photo shows Taira Beach, The coast is being protected by artificial reefs. It is under the surface of the sea to take into consideration of the scenery. So it is hard to see.

Gesashi river Mangrove (Hirugi park)

Mangrove in the Gesashi river is the most largest scale in Okinawa. We were able to see "Siomaneki(Japanese name)" crubs that was characterized by having a large hand at only one side.

The last point we visited was Sukubama Beach. The view of the beach was enchanting and breathtaking.

THOUGHTS

In the end, I would like to say that our trip was very interesting and informative.