Observation of Morphology and Flow Motion at the River Mouth of Tenryu River with X-band Radar

Abstract

An X-band nautical radar system was employed and averaged radar images were analyzed to observe morphology and flow motion around the river mouth of Tenryu-river, Sizuoka, Japan, from June to December of 2007. Sand bar at the river mouth breached due to flooding during the attack of Typhoon MAN-YI in July, 2007. The width of the main channel increased approximately from 50 m to 250 m. The breeched part was buried gradually and sand bar showed a recovery with supply of sediments from the seaside. River flow front-like patterns in the vicinity of seaside of the river mouth were observed frequently in the averaged images. The patterns in the averaged images were compared with sea surface colors of a satellite image, confirming river flow front penetration into the coastal water was captured with the radar. 1.•@•• OE¾ "V-³ •ì ‰Í OEû ‚Ì ‚ ‚é‰" •B "å ‚Ì Še ŠC ŠÝ ‚Í'S "Ê "I ‚É•N •H OEX OEü ‚É ‚ ‚è,‰Í •ì ‚© ‚ç‚Ì"y •» ‹Ÿ ‹‹ ‚ð '£ •i ‚µ,‚± ‚ê ‚ð‰ˆŠÝ‚ð‰ˆŠÝ ‚É "g ‹y ‚³ ‚¹ ‚邽 ‚ß ‚Ì OEŸ "¢ ‚ª ‚È ‚³‚ê ‚Ä ‚¢ ‚é.‚» ‚̈ê‚Ìˆê ‚Â ‚AE ‚µ‚Ä ƒ_ ƒ€•Ä •Ò Ž-‹AE(•l •¼ ‰Í •ì •' "¹ Ž-± •Š,ŽQ •AE2008-05-07)‚ª '… Žè ‚³ ‚ê,•¡ OEã,-¬ ˆae ‚© ‚çŠCˆae‚çŠCˆae ‚Ö ‚Ì"y •» ‹Ÿ ‹‹ ‚ª '• ‚· ‚AEŠú 'Ò ‚³ ‚ê ‚é.‰Í •ì ‚© ‚ç‹Ÿ ‹‹ ‚³‚ê ‚½"y •» ‚Í ‰Í OEû ‚ðOEo ‚ÄŠCˆae‚ÄŠCˆae ‚É ˆÚ "® ‚· ‚é‚Ì ‚Å,‰Í OEûˆae ‚É‚¨‚¯‚É‚¨‚¯ ‚é-¬ "®,"y •» ˆÚ "® ‚È ‚Ç ‚É‚Â ‚¢ ‚Ä'm ‚é ‚± ‚AE‚ª ‰ˆŠÝˆae‰ˆŠÝ‰ˆŠÝˆae ‚Ö ‚Ì OEø-¦ "I ‚È "y •» ‹Ÿ ‹‹ ‚É ‚ ‚È ‚ª ‚é. ‚± ‚Ì OE¤ ‹ † ‚Å ‚Í,Xƒo ƒ" ƒhƒOE•[ ƒ_ ‚ð-p ‚¢,2007"N6OEŽ ‚© ‚ç 12OEŽ ‚Ì ŠÔ ‚Ì "V-³ •ì ‰Í OEûˆaeOEûˆae ‚Ì 'n OE`OE`•Ï ‰» ‚AE-¬ "® ‚ð'² ‚× ‚½ OE‹ ‰Ê ‚ð•ñ •• ‚· ‚é.'ä •-‚Ì-ˆ •P ‚É"º ‚¤•o •… ‚É ‚ae ‚èOEˆ‰ó‚èOEˆ‰ó ‚µ‚½ ‰Í OEû •» •B ‚Ì ‰ñ •oe ‰ß 'ö ‚ð•à-¾ ‚µ,‚Ü ‚½,‰Í OEû‚© ‚ç‰" ‚Ñ ‚é‰Í •ì •… ƒt ƒ• ƒ" ƒg‚Ì ‹" "® ‚ðOEŸ "¢ ‚µ‚½. 2.•@ŠÏ 'ª ‚Ì ŠT-v "V-³ •ì ‰Í OEû ‰E ŠÝ ‚É ‚ ‚鉺 •… •ˆ-• Ž{ •Ý ‚Ì ‰® •ã ‚ÉXƒo ƒ" ƒh ƒOE •[ ƒ_ ‚ð •Ý 'u ‚µ2007"N6OEŽ ‚ae ‚èŠÏ 'ª ‚ð •s ‚Á ‚½.ƒOE •[ ƒ_‰ae 'oe ‚É ‚Í"g ‚Ì•i •s •ó ‹µ,•… •Û ˆÊ 'u ‚È ‚Ç‚ª ‰f ‚é.•}-1‚É ŠÏ 'ª ƒT ƒC ƒg,•À •W OEn,ƒOE •[ ƒ_‰ae 'oe ‚ð •½ ‹Ï ‰» ‚µ‚½•½ ‹Ï ‰ae 'oe(•¼-{ •E•• Žá,2005)‚È ‚Ç ‚ðŽ¦ ‚·.•À •W OEn ‚Í•½-Ê '¼ Šp •À •W OEn (VIIIOEn)‚ð ŽQ •l ‚É,"OE •¼ •û OEü ‚ÉxŽ²,"ì-k •û OEü ‚ÉyŽ² ‚ð •Ý 'è ‚µ‚½.•½ ‹Ï ‰ae 'oe ‚͉ð •Í ‚É-p ‚¢ ‚é•" •ª ‚ðŽae ‚è•o ‚µ‚Ä•\ Ž¦ ‚µ‚Ä ‚ ‚é.‹P "x 'l ‚Ì'å ‚«‚¢•" •ª ‚ª-¤ ˆae ‚É 'Î ‰ž ‚µ‚Ä ‚¨‚肨‚è, ‰Í "¹ "à ‚Ì•» •B,‰Í OEû,‰Í OEû •» •B ‚Ì•… •Û ˆÊ 'u,‰Í •ì •… ƒt ƒ• ƒ" ƒg‚Ì "-• ¶ ‚È ‚Ç ‚Ì•ó ‹µ ‚ð "» "Ç ‚Å ‚« ‚é. •½ ‹Ï ‰ae 'oe ‚ae ‚è•… •ÛˆÊ 'u ‚ð "Ç ‚Ý Žae ‚è,•‚ •ª ‰ð "\ ‰q •¯ ‰ae 'oe (a) (b) •}-1•@ (a)ŠÏ 'ª-Ì ˆae(b)•À •W OEn ‚AE•½ ‹Ï ‰ae 'oe(ŠÏ 'ª "ú:2007"N 6OEŽ8"ú21Žž) (a)•@-¬-Ê,•~ ‰J-Ê,ƒOE •[ƒ_ŠÏ'ª "ú,‰Í•ì •…ƒtƒ•ƒ" ƒg ‰ð •Í "ú (b)•@-L‹`"g•‚ •}-2•@ ŠÏ'ª ŠúŠÔ ' † ‚Ì-¬-Ê ‚AE"g•‚ 1•@ •³ ‰ïˆõ‰ïˆõ •H"Ž '}"g'åŠw •y‹³ Žö 'åŠw‰@ ƒVƒXƒeƒ€•î•ñ •H ŠwOE¤‹ †‰È 2•@ Šw • ¶ ˆõ '}"g'åŠw'å Šw‰@ ƒVƒXƒeƒ€•î•ñ•HŠwOE¤‹ †‰È 3•@ •³ ‰ïˆõ‰ïˆõ "Ž(•H)"OE ‹ž'åŠw•y‹³Žö 'åŠw‰@•HŠwOEnOE¤‹ †‰È 3•@ ƒtƒFƒ••[ •H"Ž "OE‹ž'åŠw‹³Žö 'åŠw‰@•HŠwOEnOE¤‹ †‰È