Experimental Study of Sediment Transport caused by Tsunami

Abstract

The sediment transport caused by tsunami was measured by a simple experiment. We measured the velocities and suspended concentrations caused by one solitary wave which is assumed as tsunami passing on the plane sand bed without breaking and splitting. It was found that there are phase lag between peaks of suspended concentration and velocity, and the time variations of vertical distribution of suspended concentration are in good agreement with approximated curve with exponential function. We found that the Brown's formula is inconsistent with the time variations of sediment flux measured in the experiment because it can't explain the phase lag between velocities and total sediment flux. The bed load formula by Ashida-Michiue shows a close agreement with amount of bed load. 1.•@‚Í ‚ ¶ ‚ß ‚É ‰ˆŠÝˆae‰ˆŠÝ‰ˆŠÝˆae ‚É-ˆ •P ‚µ‚½'à "g ‚Í,‚» ‚Ì"g-Í ‚É ‚ae ‚é•\ '¢ •¨ ‚Ö ‚Ì ‰e ‹¿ ‚à‚³ ‚é ‚± ‚AE ‚È‚ª ‚ç,‰ˆŠÝˆae‰ˆŠÝ‰ˆŠÝˆae ‚É'å ‹K-Í ‚È •» ˆÚ "® ‚ð "-• ¶ ‚³‚¹ ‚é ‚± ‚AE‚ª Žw "E ‚³ ‚ê ‚Ä ‚¢ ‚é.‰ˆŠÝˆae‰ˆŠÝ‰ˆŠÝˆae ‚É-§ 'n ‚· ‚é"-"d •Š ‚É ‚¨‚¢‚¨‚¢ ‚Ä ‚Í,'à "g-ˆ •P Žž ‚Ì •» ˆÚ "® ‚É ‚ae ‚è,Žae •… OEû•" ‚ª-"-v ‚· ‚é ‚± ‚AE‚ª OEoe "O ‚³ ‚ê ‚Ä ‚¢ ‚é.‚» ‚Ì ‚½ ‚ß,'à "g-ˆ •P Žž ‚É •` ˜p "à ŠO ‚Å ‚Ì•» ˆÚ "® ‚ð'è-Ê "I ‚É-\'ª ‚· ‚éŽè-@ ‚ª•K-v ‚AE‚È ‚Á ‚Ä ‚¢ ‚é(•å ŽR ‚ç(2007),-Ø OE´•OE´•E•¼ ŽR(2007)). ‚±‚ê ‚Ü ‚Å ŽÀ OE± "I OEŸ "¢ ‚É ‚ae ‚è,•]-ˆ ‚Ì-¬ •»-Ê Ž® ‚Ì 'à "g ‚É 'Î ‚· ‚é"K ‰ž •« ‚É ‚ ‚¢ ‚Ä ‚ÍOEŸ "¢ ‚ª ‚È ‚³ ‚ê ‚Ä ‚¢ ‚é(-á ‚¦ ‚Î, "¡ ˆä ‚ç(1998)).‚µ ‚© ‚µ,‚± ‚ê ‚Ü‚Å ‚Ì 'à "g ‚É ‚ae ‚é•» ˆÚ "® ŽÀ OE± ‚É ‚ÍŠô ‚Á ‚© ‚Ì-â 'è "_ ‚ª ‚ ‚é.'ae1‚É,ŠÇ˜H ŠÇ˜H ‚ð-p ‚¢ ‚Ä 'à "g ‚Ì-¬ '¬ ‚ð-Í ‹[ ‚µ‚½ ŽÀ OE± ‚â,•» ‚Ì 'ã ‚í ‚è‚É"ä •d ‚Ì OEy ‚¢-± Žq ‚ð-p ‚¢ ‚éŽÀ OE± ‚Å ‚Í,ŽÀ •Û ‚Ì 'à "g ‚É ‚ae ‚é•» ˆÚ "® OE» •Û ‚ð •Ä OE» ‚Å ‚« ‚Ä ‚¢ ‚È ‚¢ ‰Â "\ •« ‚ª ‚ ‚é.'ae2‚É,‚± ‚ê ‚ç‚Ì OE¤ ‹ † ‚É ‚¨‚¢‚¨‚¢ ‚Ä,Žž •X•• •X ‚Ì "Z "x •ª •z "™ ‚ª OEv 'ª ‚³ ‚ê ‚Ä ‚¢ ‚È ‚¢ ‚½ ‚ß,•» ‚Ì•Ú •× ‚ÈˆÚ "® OE`OE`'Ô ‚ª •s-¾ ‚Å ‚ ‚é.ŽÀ-± •ã-p ‚¢ ‚ç‚ê ‚é•½-Ê2ŽŸ OE³ OEv ŽZ ‚Å ‚Í,•‚-V •» "Z "x ‚É ‚Ç ‚Ì ‚ae ‚¤‚È ‰" '¼•ª •z OE`OE`•ó ‚ð‰¼ 'è ‚· ‚é‚© ‚É ‚ae ‚è,OEv ŽZ OE‹ ‰Ê ‚ª'å ‚« ‚-•Ï ‚í ‚é ‚± ‚AE‚ð •¼ "¨ ‚ç(2005)‚ª •ñ •• ‚µ‚Ä ‚¢ ‚é.OEv ŽZ •¸ "x ‚ð OEü •ã ‚³ ‚¹ ‚邽 ‚ß ‚É ‚à,•» ˆÚ "® ‚ÌOE`‚ÌOE`'Ô ‚É ‚ ‚¢‚Ä •Ú •× ‚É OEŸ "¢ ‚· ‚é•K-v ‚ª ‚ ‚é. ‚» ‚± ‚Å,-{ OE¤ ‹ † ‚Å ‚Í,'¢ "g '• 'u ‚ð-p ‚¢ ‚Ä "ñ •Ó "g,"ñ •ª-ô ‚Ì'à "g ‚É ‚ae ‚é•‚ ƒV•[ ƒ‹ ƒY ‰º ‚Å ‚Ì•» ˆÚ "® ‚Ì Šî 'b "IŽÀ OE± ‚ð •s ‚¢,'à "g ‚É ‚ae ‚é•» ˆÚ "® ‚ð •Ú •× ‚ÉOEv 'ª ‚· ‚é ‚± ‚AE ‚Å,‚» ‚Ì ˆÚ "® "Á •« ‚ð ‰ð-¾ ‚· ‚é ‚± ‚AE‚ð-Ú"I ‚AE‚· ‚é. 2.•@ ŽÀ OE± Žè-@ (1)•@ ŽÀ OE± '• 'u ‚¨‚ae‚¨‚ae ‚Ñ-Í OE^ ŽÀ OE± ‚É ‚Í •}-1‚É Ž¦ ‚·,'· ‚³78.0m,••0.9m‚Ì2ŽŸ OE³ '¢ "g •… ˜H ‚ð-p ‚¢ ‚½.ŽÀ OE± •… ˜H ' † ‚É ‚Í•… ˜H •• ‚ª0.3m‚AE ‚È ‚é ‹· •ó •" ‚ð•Ý ‚¯ ‚Ä ‚¨‚肨‚è,‚± ‚Ì‹· •ó •" ‚É ‚ae ‚è"g ‚Ì •… ˆÊ ‚ð•ã •¸ ‚³ ‚¹ ‚é ‚± ‚AE ‚É ‚ae ‚è,•‚ ƒV•[ ƒ‹ ƒY •" ‚Ì •ó ‹µ ‚ð "-• ¶ ‚³‚¹ ‚½. 'n OE`OE`‚Í•» 'w •" ‚ð •oe ‚« ƒ‚ ƒ‹ ƒ^ƒ‹•» ‚Ì OEÅ 'è •° ‚Å ‚ ‚é.•… ˜H ‰oe •" ‚͘p ‹È ‚µ‚½OE`‚µ‚½OE`•ó ‚AE ‚µ,•… ˜H ‚Ì-'¤ ‚Å"g ‚ð OE¸•OE¸•Š ‚³‚¹ ‚é ‚± ‚AE‚Å •… ˜H ‰oe •" ‚© ‚ç‚Ì "½ ŽË "g ‚ð-h ‚¢‚¾.