کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4532671 1325139 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Response of salinity distribution around the Yellow River mouth to abrupt changes in river discharge
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Response of salinity distribution around the Yellow River mouth to abrupt changes in river discharge
چکیده انگلیسی

To investigate how salinity changes with abrupt increases and decreases in river discharge, three surveys were conducted along six sections around the Yellow River mouth before, during and after a water regulation event during which the river discharge was increased from ∼200 to >3000 m3 s−1 for the first 3 days, was maintained at >3000 m3 s−1 for the next 9 days and was decreased to <1000 m3 s−1 for the final 4 days. The mean salinity in the Yellow River estuary area during the event varied ∼1.21, which is much larger than its seasonal variation (∼0.50) and interannual variation (∼0.05). Before the event, a small plume was observed near the river mouth. During the event, the plume extended over 24 km offshore in the surface layer in the direction of river water outflow. After the event, the plume diminished in size but remained larger than before the event. The downstream propagation of the plume (as in a Kelvin wave sense) was apparent in the bottom layer during the second survey and in both the surface and bottom layers during the third survey. The plume sizes predicted by the formulas from theoretical studies are larger than those we observed, indicating that factors neglected by theoretical studies such as the temporal variation in river discharge and vertical mixing in the sea could be very important for plume evolution. In addition to the horizontal variation of the plume, we also observed the penetration of freshwater from the surface layer into the bottom layer. A comparison of two vertical processes, wind mixing and tidal mixing, suggests that the impact of wind mixing may be comparable with that of tidal mixing in the area close to the river mouth and may be dominant over offshore areas. The change in Kelvin number indicates an alteration of plume dynamics due to the abrupt change in river discharge during the water regulation event.

Research highlights
► We observed salinity distribution before, during and after a water regulation event.
► The diluted water showed asymmetric evolution patterns in surface and bottom layers.
► Effects of wind mixing and tidal mixing on salinity distribution were examined.
► The abrupt change in river discharge led to a dynamical alteration of plumes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Continental Shelf Research - Volume 31, Issue 6, 15 April 2011, Pages 685–694
نویسندگان
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