| Harbor is an important node of communications and transportation, it is also an important part of comprehensive transportation system. It can be called the pivot of communications and transportation and the strategic point of combined water-land transport. Nothing can take the place of harbor's position in national economy. Breakwater is the structure that formed inner harbor with protected water area, it is the important structure of harbor, of which the function is ensuring the water area inner be protected of being suffered from wave attack when ship navigating, anchoring and operating.The paper researches planning of breakwater, and studies the optimizing method during harbor planning. As well known, the shorter the length of outer dike is, the less the investment of the construction costs, and vice versa. It is a complex problem to plan the axis. So, optimization of breakwater planning is of great practical value and should be resolved immediately.At first, the paper narrates the development of numerical modeling, which includes shallow water dynamics theory and method, and compares the Boussinesq model and mild-slope equation model. The purpose is to select one model that best fit for wave calculation in harbor engineering. It also gives the test of optimizing model and calculates the fitness.The paper gives a new concept of numerical harbor, which has not been mentioned before. Because it is possible to obtain data about water depths, tidal currents, waves, sediment and ship styles in a harbor zone, so such data could be used in numerical calculation which is used to adjust the operating mode and forecast the catastrophic conditions. The opinion the paper is that the numerical harbor should not only have the function of inquiry in layers as GIS does, but also have the certain ability of analysis and calculation. It can provide strong support for operators and managers of the harbor. Therefore, numerical harbor is defined as an intelligent system with multiple auxiliary functions, which based on harbor database and calculation models as well. There are two purposes in numerical harbor: one is to reduce the investment of harbor, it includes planning breakwater and selecting water way more reasonably, the other is to increase the benefit of harbor, the main content of which is to reduce maintenance cost and to take operation decision according to the natural conditions. In this paper, the numerical harbor should include following contents: 1 .Database of wave field, tidal current field, sediment field in researched area; 2.Database of ship styles. 3.Numerical model used to analysis data. 4.Plans of outer dike, utilities of sea line, and selections of waterway, which based on the above databases. 5.Optimized operation mode according to the above analysis.Optimization of harbor breakwater can also be regarded as one part of numerical harbor. The paper introduces the theory and technology of optimization into wavecalculation in order to draw a new conclusion. Because the purpose of optimization of breakwater planning in harbor is to reduce the quantity of works with the premise that the protected water area is enough. It is a complex and nonlinear problem, so the paper selects the Genetic Algorithm (GA) as the optimizing tool and forms a GA model of breakwater planning. It is the obvious that using GA to optimize breakwater is a correct way. In the paper, the GA operations as fitness calculation, production, selection, duplication, crossover and mutation are investigated.Founding a GA objective function and calculating the fitness are key work in optimization of breakwater planning. The paper defines the objective function as: minimizing the quantity of works under the condition of enough water area and depth according with the national codes.The paper narrates the development and main technology of GA, and changes the above problem with restraint conditions into the maximizing problem without restraint conditions, the way the paper chooses is the punish function method. The calculation...
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