Salinity Restoration in the Bohai Bay under the Scene of Increase Runoff to Sea

摘要

Along with reduction of the runoff entering the sea, the salinity of Bohai Bay presents an obvious trend of escalation. The ecosystem in the sea has been harmed obviously by the high salinity of sea area environment. In this article, firstly, the problem of salinity rise faced by Bohai Bay was studied. Then the ecological water requirement of the main river estuary in the Bohai Bay was been analyzed initially based on some related research. At last according to the increase runoff plan from the dual model, the various trend of the salinity in the sea area was simulated under different scenes, and the concept of salinity restoration level was proposed to make an assessment on the effect to the sea area ecological environment salinity by the different scene plan. The results indicated that compared with the historical water condition, the salinity restoration in Bohai Bay was more obvious by the fifth plan which was taken as the medium-term goal and the seventh and eighth plan which was taken as the allocative decision at a specified future date. The above plans achieved 60% historical salinity level approximately, which almost fulfilled the salinity request by the ecosystem in the nearshore water of Bohai Bay. However the first plan which was taken as the present situation was very despondent, the salinity restoration level was less than 10%, which was very difficult to fulfill the request of improved sea area salinity.