||Comparisons of Regional Wave Climate along the Sea of Japan Coast
Nguyen, Trinh Chung ,
Yuhi, MasatoshiUeno, Takuya
28 , 2016-03-22 , 金沢大学環日本海域環境研究センター = Institute of Nature and Environmental Technology Kanazawa University
This study examines the long-term wave data observed along the coastline of the Sea of Japan. The focus was mainly placed on the wave climate at Wajima Port, which is located on the outer coast of the Noto Peninsula in Ishikawa Prefecture. The wave characteristics at Wajima were first compared with those at Kanazawa, which is located relatively close (90 km) to Wajima. The wave climate at Wajima and Kanazawa indicated similar features in terms of wave height and period. The influence of Noto Peninsula was substantial only in terms of the incoming wave direction. While neither a statistically significant trend nor jump was found for the long-term variation of annual wave height at these sites, an increasing trend and an abrupt jump around 1990 have been detected in the long-term variation of wave periods at Kanazawa. The wave periods in July have significantly increased at both Wajima and Kanazawa. The wave properties were then compared with those at Rumoi and Hamada Port, which are respectively located 830 km and 510 km away from Wajima. Over a long stretch of the Sea of Japan coast covering Rumoi, Wajima, Kanazawa, and Hamada, wave climate indicated similar and significant seasonal changes. The difference in the properties of significant waves around these four sites was about 10 %. Significant wave height and period correlated very well with second order polynomials at each site. In contrast, wave directions along the coastline indicated significant differences. At Rumoi and Hamada, neither significant trends nor jumps in long-term annual wave periods were detected. The statistical test revealed that the long-term increasing trends and abrupt jumps of wave period in summer were intrinsic to the waves at Wajima and Kanazawa, located in the central coastal areas adjacent to the Sea of Japan.