长江河口北支新村沙围垦工程对盐水入侵的影响
|
摘要
长江河口北支新村沙围垦和南水道封堵工程于2012年实施,人为改变了北支河势.本文采用长期应用、改进和验证的长江河口三维盐水入侵数值模式,考虑1月和2月平均径流量和风况,计算和分析北支新村沙围垦工程对北支盐水倒灌以及南支青草沙水库、陈行水库和东风西沙水库取水的影响.在北支新村沙下游,围垦工程导致盐水入侵加强,盐度上升0.05~0.10;在新村沙上游,盐水入侵减弱,盐度下降0.05~1.0.工程导致在大潮后中潮、小潮、小潮后中潮、大潮期间北支上段断面平均倒灌盐通量分别下降百分比分别为7.52%、16.48%、10.17%、6.94%.北支倒灌的减弱,导致南支盐度低于0.45的淡水面积增大.大潮后中潮、小潮、小潮后中潮、大潮期间表层平均盐度在东风西沙水库取水口分别下降了4.52%、10.23%、9.15%、5.81%,连续不宜取水时间由10.1 d减少到9.3 d;陈行水库取水口分别下降了10.59%、13.11%、32.89%、13.95%,连续不宣取水时间由5 d减少到4.4 d;青草沙水库取水口分别下降了10.50%、8.19%、9.17%、11.99%,连续不宜取水时间由6.2 d减少到5.1 d.北支新村沙围垦工程缩窄了过水断面,减弱了北支倒灌,有利于南支水源地淡水资源的利用.
The reclamation project of enclose Xincunsha and block its southern channel in the North Branch of the Changjiang Estuary was conducted in 2012,resulting in the river regime changed artificially.Considering the monthly mean river discharge and wind in January and February,the 3-D saltwater intrusion numerical model in the Changjiang estuary,which has been applied,improved and validated for long-term,was used to investigate the influences of the saltwater-spill-over(SSO) from the north branch into the South Branch and the water intakes of Qingcaosha,Chenhang and Dongfengxish reservoirs due to the project.The saltwater intrusion is enhanced and salinity increases 0.05~0.10 downstream Xincunsha,whereas is weakened and salinity decreases 0.05 ~1.0 upstream Xincunsha due to the project.The tidally averaged salt fluxes of SSO cross the section at upper reaches of the North Branch reduced 7.52%,16.48%,10.17%,6.49%during moderate tide following spring tide,neap tide,moderate tide following neap tide,spring tide after the project,respectively.The reduce of the SSO induces an increase of freshwater area in the South Branch.The tidally averaged surface salinity at the water intakes of reservoir during moderate tide following spring tide,neap tide,moderate tide following neap tide,spring tide is reduced by 4.52%,10.23%,9.15%,5.81%at Dongfengxisha,by10.59%,13.11%,32.89%,13.95%at Chenhang,and by 10.50%,8.19%,9.17%,11.99%at Qingchaosha,respectively.Correspondingly,the longest continuous unsuitable days for water intake decrease from 10.1 to 9.3 days at Dongfengxisha,from 5 to 4.4 days at Chenhang,and from 6.2 to 5.ldays at Qingchaosha.The reclamation project of Xincunsha narrowed water flow cross section,and weakened the SSO,which is favor of the utilization of freshwater in the South Branch.
The reclamation project of enclose Xincunsha and block its southern channel in the North Branch of the Changjiang Estuary was conducted in 2012,resulting in the river regime changed artificially.Considering the monthly mean river discharge and wind in January and February,the 3-D saltwater intrusion numerical model in the Changjiang estuary,which has been applied,improved and validated for long-term,was used to investigate the influences of the saltwater-spill-over(SSO) from the north branch into the South Branch and the water intakes of Qingcaosha,Chenhang and Dongfengxish reservoirs due to the project.The saltwater intrusion is enhanced and salinity increases 0.05~0.10 downstream Xincunsha,whereas is weakened and salinity decreases 0.05 ~1.0 upstream Xincunsha due to the project.The tidally averaged salt fluxes of SSO cross the section at upper reaches of the North Branch reduced 7.52%,16.48%,10.17%,6.49%during moderate tide following spring tide,neap tide,moderate tide following neap tide,spring tide after the project,respectively.The reduce of the SSO induces an increase of freshwater area in the South Branch.The tidally averaged surface salinity at the water intakes of reservoir during moderate tide following spring tide,neap tide,moderate tide following neap tide,spring tide is reduced by 4.52%,10.23%,9.15%,5.81%at Dongfengxisha,by10.59%,13.11%,32.89%,13.95%at Chenhang,and by 10.50%,8.19%,9.17%,11.99%at Qingchaosha,respectively.Correspondingly,the longest continuous unsuitable days for water intake decrease from 10.1 to 9.3 days at Dongfengxisha,from 5 to 4.4 days at Chenhang,and from 6.2 to 5.ldays at Qingchaosha.The reclamation project of Xincunsha narrowed water flow cross section,and weakened the SSO,which is favor of the utilization of freshwater in the South Branch.
引文
[1]沈焕庭,茅志昌,朱建荣.长江河口盐水入侵[M].北京:海洋出版社,2003:16.
[2]LI L,ZHU J R,WU H.Impacts of wind stress on saltwater intrusion in the Yangtze Estuary[J].Sci China Earth Sci,2012,55(7):1178-1192.
[3]LI L,ZHU J R,WU H,et al.Lateral saltwater intrusion in the north channel of the Changjiang Estuary[J].Estuaries and Coasts,2013,DOI 10.1007/sl2237-013-9669-1
[4]项印玉,朱建荣,吴辉.冬季陆架环流对长江河口盐水入侵的影响[J].自然科学进展,2009,19(2):192—202.
[5]茅志昌,沈焕庭,肖成献.长江口北支盐水倒灌南支对青草沙水源地的影响[J].海洋与湖沼,2001,32(1):58—66.
[6]顾玉亮,吴守培,乐勤.北支盐水入侵对长江口水源地影响研究[J].人民长江,2003.34(4):1—4.
[7]WU H,ZHU J R,CHEN B R,et al.Quantitative relationship of runoff and tide to saltwater spilling over from the North Branch in the Changjiang Estuary:A numerical study[J].Estuarine,Coastal and Shelf Science,2006,69,125-132.
[8]朱建荣.海洋数值计算方法和数值模式[M].北京:海洋出版社,2003:72—126.
[9]朱建荣,朱首贤.ECOM模式的改进及在长江河口、杭州湾及邻近海区的应用[J].海洋与湖沼,2003,34(4):364—374.
[10]WU H,ZHU J R.Advection scheme with 3rd high order spatial interpolation at the middle temporal level and its application to salt water intrusion in the Changjiang Estuary[J].Ocean Modelling,2010,33:31-51
[11]CHEN B R,ZHU J R,FU L H.Formation mechanism of the freshwater zone around the Meimao Sandbank in the Changjiang Estuary[J].Chinese Journal of Oceanology and Limnology,2010,28(16):1329-1339.
[12]LI L,ZHU J R,WU H,et al.A numerical study on the water diversion ratio of the Changjiang Estuary during the dry season[J].Chinese Journal of Oceanology and Limnology,2010,28(3):700-712.
[13]WU H,ZHU J R,CHOI B H.Links between saltwater intrusion and subtidal circulation in the Changjiang Estuary:A model guided study[J].Continental Shelf Research,2010,30:1891-1905.
[14]朱建荣,吴辉,李路,等.极端干旱水文年(2006)中长江河口的盐水入侵[J].华东师范大学学报:自然科学版,2010(4):1—6,25.
[2]LI L,ZHU J R,WU H.Impacts of wind stress on saltwater intrusion in the Yangtze Estuary[J].Sci China Earth Sci,2012,55(7):1178-1192.
[3]LI L,ZHU J R,WU H,et al.Lateral saltwater intrusion in the north channel of the Changjiang Estuary[J].Estuaries and Coasts,2013,DOI 10.1007/sl2237-013-9669-1
[4]项印玉,朱建荣,吴辉.冬季陆架环流对长江河口盐水入侵的影响[J].自然科学进展,2009,19(2):192—202.
[5]茅志昌,沈焕庭,肖成献.长江口北支盐水倒灌南支对青草沙水源地的影响[J].海洋与湖沼,2001,32(1):58—66.
[6]顾玉亮,吴守培,乐勤.北支盐水入侵对长江口水源地影响研究[J].人民长江,2003.34(4):1—4.
[7]WU H,ZHU J R,CHEN B R,et al.Quantitative relationship of runoff and tide to saltwater spilling over from the North Branch in the Changjiang Estuary:A numerical study[J].Estuarine,Coastal and Shelf Science,2006,69,125-132.
[8]朱建荣.海洋数值计算方法和数值模式[M].北京:海洋出版社,2003:72—126.
[9]朱建荣,朱首贤.ECOM模式的改进及在长江河口、杭州湾及邻近海区的应用[J].海洋与湖沼,2003,34(4):364—374.
[10]WU H,ZHU J R.Advection scheme with 3rd high order spatial interpolation at the middle temporal level and its application to salt water intrusion in the Changjiang Estuary[J].Ocean Modelling,2010,33:31-51
[11]CHEN B R,ZHU J R,FU L H.Formation mechanism of the freshwater zone around the Meimao Sandbank in the Changjiang Estuary[J].Chinese Journal of Oceanology and Limnology,2010,28(16):1329-1339.
[12]LI L,ZHU J R,WU H,et al.A numerical study on the water diversion ratio of the Changjiang Estuary during the dry season[J].Chinese Journal of Oceanology and Limnology,2010,28(3):700-712.
[13]WU H,ZHU J R,CHOI B H.Links between saltwater intrusion and subtidal circulation in the Changjiang Estuary:A model guided study[J].Continental Shelf Research,2010,30:1891-1905.
[14]朱建荣,吴辉,李路,等.极端干旱水文年(2006)中长江河口的盐水入侵[J].华东师范大学学报:自然科学版,2010(4):1—6,25.
目录