Abstract
Long-term evolution of Miyazaki Coast was investigated in terms of four aspects, geology and geography,
 comparison of shoreline in available maps and photographs, sediment retention analysis in watershed scale and sediment size as well as luminescence measurements of foreshore sediments. Geological and geographical analysis revealed steep topography in northern part and fluvial plain on the southern part. The total rate of sediment retention in reservoirs was found to be as much as 1.9 million m3/year. Historical shoreline retreat in the recent 200 years was significant in the northern region whereas severe erosion was developed in the last decades on the southern region close to the rivermouths of the Hitotsuse River and the Ooyodo River. The sand grain size and the thermoluminescence intensity were both found to decrease from north to south, implying the dominant direction of longshore sand transport is from north to south.
Highlights
Long-term evolution of Miyazaki Coast was investigated in terms of four aspects, geology and geography, comparison of shoreline in available maps and photographs, sediment retention analysis in watershed scale and sediment size as well as luminescence measurements of foreshore sediments
Beach sediments are supplied from four major rivers, Mimigawa River, Omaru River, Hitotsuse River and Ooyodo River
In order to understand the long-term morphology of the Miyazaki Coast, analyses were made in this study on the following four aspects; (1) geography and geology, (2) sediment retention in reservoirs, (3) shoreline change revealed from existing maps and aerial photographs, and (4) beach sediment size and luminescence
Summary
Long-term evolution of Miyazaki Coast was investigated in terms of four aspects, geology and geography, comparison of shoreline in available maps and photographs, sediment retention analysis in watershed scale and sediment size as well as luminescence measurements of foreshore sediments. Severe coastal erosion has been observed in recent years especially on the Sumiyoshi Beach located in the southern region near the rivermouth of the Ooyodo River. Looking at the shape of eroded beach, it is considered that the direction of longshore transport is from south to north, since the north end of structure is severely eroded.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
