The Analysis of Sediment Transport of Miyazaki Coast by the Sand Tracer Experiment

Abstract

The purpose of this study is to analyze the sediment transport of Miyazaki Coast, especially the dominant longshore direction of sand transport, from the results of recent 3 years sand tracer experiment and of the analysis of currents observed by camera systems during the experiment. The dominant direction obtained by accumulation of longshore sediment transport rate estimated by equation of Kraus et al.(1982), which is based on the breaking wave height and nearshore currents, agrees with the direction of motion of the tracer. In addition, it becomes clear that there is a high correlation between the distance of tracer movement and the longshore sediment transport rate. It is also obvious that sediment transport to south is predominant in the experiment period.

Evaluation of Beach Nourishment on Miyazaki Coast

“…Sato et al 8) and Sugiyama et al 9) investigated the characteristics of long term sediment transport in Miyazaki Coast. Higashi et al 10) also investigated sediment transport around the Hitotsuse River mouth based on Luminescence measurements.…”

Evaluation of beach nourishment works on Miyazaki coast in Japan

“…Sato et al [6] and Sugiyama et al [7] investigated the characteristics of long-term sediment transport in Miyazaki Coast. Higashi et al [8] also studied sediment transport around the Hitotsuse River mouth based on Luminescence measurements.…”

Observation of Sediment Dynamics in the Nearshore Region using Fluorescent Sand Tracers

“…1. はじめに 砂浜海岸の沿岸域の地形形状は、砕波、波、流 れ等による底質の浮遊や岸沖方向・沿岸方向への 漂砂により時々刻々変化している．特に、砕波帯 では活発な底質移動が生じることから、砕波によ る底質浮遊(例えば、 [1,2]) 、波・流れによる影 響(例えば、 [3,4])などの検討が数多くなされて いる。また、主に砕波帯沖側に形成されるアウタ ーバー(沿岸砂州)に関しても、その形成(例え ば、 [5])や移動(例えば、 [6,7])に関する検討 がなされている。また、遡上帯に関しても底質移 動量が海岸侵食、堆積に直結することから、漂砂 量の算出(例えば、 [8]) 、高波浪時と静穏時の汀 線移動動態把握(例えば、 [9,10]) 、また、堆積性 地形であるバームの侵食堆積 [11]やその漂砂量分 布特性の検討 [12] [13]) 、構造物周りの底質移 動動態 [14]、沿岸漂砂 [15]、また底質の鉛直混合 の検討(例えば、 [16,17])などがなされている． 国内においても、底質移動方向と移動速度、鉛直 混合過程 [18]、沿岸域での底質移動調査 [19] Fig. 2 Observed time series data, (a) 2014 observations and (b) 2015 observations; (i) significant wave height, (ii) significant wave period, (iii) wave direction and (iv) wind speed.…”