Study On Erosion And Deposition In The Laizhou Bay Before And After Recolamation

According to the important instruction,'building of Shandong peninsula economic zone on the blue', generated by General Secretary Hu Jintao, in order to grasp the new trends of the development of marine economy in the world and expand the development space of the land and the sea, in the first half of the year 2009, Shandong provincial party Committee and provincial Government promulgated the guidance on building blue economic zone in Shandong peninsula and made a comprehensive building concept. The concept contains 9 sea areas for intensive use, which may reconstituted a county on the sea. Such a massive change will inevitably change the marine environment, thereby affecting the economic development and the future plan. As a core of the blue economic zone, Laizhou Bay owns four of the nine blocks. After the planned reclamation, the tide, wave and sediment transport conditions of Laizhou Bay will change, and thereby affect the marine environment and the regional sustainable economic development.Based on the analysis of the sediments distribution and the characteristics of the terrain, the currents, the waves and the water depth of Laizhou Bay, MIKE 21 Two dimensional simulation platform is used to establish the tidal current and wave field before and after the reclamation and then couple both to simulate scour and silting evolution before and after the reclamation, and after that the assessment for the suitability of the sea reclamation for construction use in the Laizhou Bay is carried out. Simulation results show that:[1] after the planned reclamation, tidal current field will change a lot near the planned reclamation area. Near the docks and the extrude place of the new coastline, the velocity increases by the enhanced hydrodynamic condition, the incremental number above 15cm/s; and at the inside of the new harbour and the backoff place of the new coastline, the weakened hydrodynamic condition decreases the velocity, where the amount reduces more than 20cm/s. It is about 3000～4000m outside the new coastline that the planned reclamation has little effect on the tide. [2] equal to or greater than before and after this simulated the planned reclamation of laizhou Bay 6 -level wind 24h wave field after. Results show that after the planned reclamation, in parallel to the shoreline near the new line or a new narrow waterway forming regional, effective wave heights generally decreases, the maximum reduction 2～88cm; in part near new line perpendicular to the original shoreline, significant wave height increase maximum incremental 0～40cm. The planning horizon for the area of sea wave conditions for 1500-2000m. [3] whether static wind under ideal conditions or under the action of wind and waves, after the planned reclamation, year of the planning scheme area, near river is a greater change in thickness. Calm conditions, planning both before and after reclamation area in the deposition State, amount of sediment deposition generally decrease after the planned reclamation, reduction in 0～0.5cm/a between before and after the planned reclamation area is in a State of erosion, erosion strengthened after the planned reclamation, increased volume in the 0～0.5cm/a range. Wind conditions, the area before and after the planned reclamation were generally in a State of erosion and erosion strengthened after the planned reclamation, maximum scouring and silting variation in 1～2cm/a between. In new bank line to sea extrude location near, because pick flow role caused local water power conditions strengthening often formation most strong rushed corrosion area, static wind Shi maximum rushed corrosion volume 1.5～2.5cm/a, Gale Shi maximum rushed corrosion volume 2.4～7.2cm/a; in new bank line to land recessed Department, due to water power conditions weakened and became main sedimentation area, static wind Shi maximum sedimentation volume for 0.4～1.8cm/a, Gale Shi maximum sedimentation volume for 0～1.5cm/a. After reclamation planning, planning in the vicinity of individual sea areas from erosion or sedimentation into the opposite, the scouring and silting variation in 2cm/a above. The planning horizon for the area to scour the sea conditions when the static wind 1000～3500m, when wind is 1200～3400m. [4] the application of planning and reclamation of land suitability assessment of methods on planning of laizhou Bay reclamation project was assessed. Focus on planning more detailed Longkou Bay marine equipment manufacturing cluster project for reclamation suitability evaluation of land for construction purposes. The cluster contains the Longkou and Zhaoyuan two planned reclamation. Assessment results display, Longkou planning area planning filled sea area control value for 1945.143 million Yuan/ hectares, is greater than area [Bank line] control index standard 1907.325 million Yuan/hectares; Bank line control value for 1716.59 million Yuan/ hectares, is greater than bank line control index standard 54.586 million Yuan/ hectares. Zhaoyuan planned reclamation planning scheme area control values to 2435.83 million/HA, is greater than the area of control standards 1961.82 million/HA; line control indicator standard 56.1456 million/meter, Zhaoyuan area without coast line. Therefore, marine equipment manufacturing industry agglomeration area of Longkou Bay reclamation planning of project area (coastline) area control value meets the (line) standard, used in the construction planning, reclamation and have suitability. Comprehensive Longkou Bay marine equipment manufacturing agglomeration area, and laizhou marine new energy industry agglomeration area, and Weifang sea Metro, and Dongying oil industry agglomeration area, four a planning filled area area (Bank line) control index standard of calculation results, learned that future laizhou Bay construction with sea filled sea made to project units area investment is greater than 1961.82 million Yuan/hectares, and occupied units length Bank line investment is greater than 56.1456 million Yuan/m Shi, the planning filled Sea project for suitable filled Sea project. When the future planning of reclamation, for improvement of reclamation project design or additional measures to protect environmental resources, to minimize the adverse effects of reclamation projects on the environment.