海洋科学
海洋科學
해양과학
MARINE SCIENCES
2014年
11期
91-100
,共10页
磨刀门水道%三维数学模型%流速%盐度%实测资料
磨刀門水道%三維數學模型%流速%鹽度%實測資料
마도문수도%삼유수학모형%류속%염도%실측자료
Modaomen waterway%three dimensional model%velocity%salinity%field data
为探讨磨刀门水道潮流和盐度的三维分布特性，本文建立了磨刀门水道的三维潮流和盐度数值模型，采用2009年枯季磨刀门水道实测潮流和盐度资料对模型参数进行率定和验证。结果显示，枯季由于上游径流量小，磨刀门水道总体涨、落潮流速都不大，表层总体涨潮平均流速都在0.5 m/s 以内，总体落潮平均流速在0.8 m/s以内；底层总体涨落潮平均流速都在0.5 m/s以内；从盐度的平面分布来看，磨刀门水道近口门河段总体呈现涨潮时水道东侧盐度高于西侧，落潮时东侧盐度小于西侧的趋势。大潮和中潮期间，落潮时盐水向上游的入侵距离反而较涨潮时更远，主要原因是，落潮时的底层盐水向上游的补偿流动以及地形阻拦形成更为强烈的紊动扩散。潮汐动力弱(小潮)时，整个水道内水流流速很小，流态平缓，紊动较弱，总体仍呈现涨潮时入侵距离大于落潮，显示枯季磨刀门水道盐水入侵的主要影响因素取决于地形和潮动力。
為探討磨刀門水道潮流和鹽度的三維分佈特性，本文建立瞭磨刀門水道的三維潮流和鹽度數值模型，採用2009年枯季磨刀門水道實測潮流和鹽度資料對模型參數進行率定和驗證。結果顯示，枯季由于上遊徑流量小，磨刀門水道總體漲、落潮流速都不大，錶層總體漲潮平均流速都在0.5 m/s 以內，總體落潮平均流速在0.8 m/s以內；底層總體漲落潮平均流速都在0.5 m/s以內；從鹽度的平麵分佈來看，磨刀門水道近口門河段總體呈現漲潮時水道東側鹽度高于西側，落潮時東側鹽度小于西側的趨勢。大潮和中潮期間，落潮時鹽水嚮上遊的入侵距離反而較漲潮時更遠，主要原因是，落潮時的底層鹽水嚮上遊的補償流動以及地形阻攔形成更為彊烈的紊動擴散。潮汐動力弱(小潮)時，整箇水道內水流流速很小，流態平緩，紊動較弱，總體仍呈現漲潮時入侵距離大于落潮，顯示枯季磨刀門水道鹽水入侵的主要影響因素取決于地形和潮動力。
위탐토마도문수도조류화염도적삼유분포특성，본문건립료마도문수도적삼유조류화염도수치모형，채용2009년고계마도문수도실측조류화염도자료대모형삼수진행솔정화험증。결과현시，고계유우상유경류량소，마도문수도총체창、락조류속도불대，표층총체창조평균류속도재0.5 m/s 이내，총체락조평균류속재0.8 m/s이내；저층총체창락조평균류속도재0.5 m/s이내；종염도적평면분포래간，마도문수도근구문하단총체정현창조시수도동측염도고우서측，락조시동측염도소우서측적추세。대조화중조기간，락조시염수향상유적입침거리반이교창조시경원，주요원인시，락조시적저층염수향상유적보상류동이급지형조란형성경위강렬적문동확산。조석동력약(소조)시，정개수도내수류류속흔소，류태평완，문동교약，총체잉정현창조시입침거리대우락조，현시고계마도문수도염수입침적주요영향인소취결우지형화조동력。
To investigate the characteristics of tidal flowing and salinity in Modaomen waterway, three dimensional hydrodynamic and salinity mathematical models were established and verified by using field data during dry season in 2009. It is shown that the total flowing velocities in Modaomen waterway were rather small during dry season. The average velocities at water surface varied within less than 0.5 m/s during flood and 0.8 m/s during ebb with velocities at bottom within 0.5 m/s. According to plane distribution of salinity in the reach close to the estuary, salinities close to east bank were less than those close to west during flood, while vice versa during ebb. Saline water intruded farther upstream during ebb than during flood under stronger tidal power (in spring and middle) because of emergence of more intensive compensation flow upstream at bottom, while saline water was diffused upstream severely during ebb for stronger turbulence and reflection by topography. However, intrusion distances of saline water during ebb were still less than that during flood in neap for weaker tidal power and turbulence with smaller velocities and gentler tidal flowing in the waterway. So the characteristics of saline water intrusion in dry season depend on tidal power and topography in Modaomen waterway.
