Study On Navigable Hydro-junction Organization Mode With Cellular Automata

In recent years, by virtue of the advantages of low costs, low consumption, and low pollution, inland waterway transportation is playing increasingly important role in national economy, and the demand of inland water transportation is growing. Meanwhile, because of the limitation of the previous engineering design level, the actual operation efficiency of partial ship lock of the water transportation hub is far from the design level. This awkward situation led the problem of insufficient lock capacity in some of the water transportation hubs. Especially when being influenced by natural situation, for example, flood, low flow and fog, the traffic jam for inland water transportation is particularly serious. Therefore, this article will analyze the transportation and organization mode in natural disaster with the object of three gorges hydro-junction area. Based on the traffic flow theory, this paper analyzes the characters of the running of ships. Moreover, Cellular Automata theory is utilized for establishing simulation model, optimizing the transportation and organization mode of the three gorges hydro-junction area, allowing Scheduling of ships in the three gorges hydro-junction area more scientific, reasonable and orderly. By doing so, it is also expected to further enhance the lock capacity and utilization rate, eliminating the anxieties on the development of inland waterway transportation. The main research content and achievements are given as follows:1) Through combination of the traditional definition of road traffic flow with the ship traffic flow, the definition of aquatic traffic flow is proposed, while the three key elements for aquatic traffic flow are also analyzed. Proceeding from the basic Cellular Automata theory, it introduces the basic structure and changing rules of aquatic one-way CA model and aquatic multiple-way CA model, and analyzes the structures and features of multiple ship domain models. After comparison, FUJII Model, which is suitable for Cellular Automata modeling, is selected as the basic model in this paper. It will be one of the most important parameters—the basis for bow distance calculation.2) By considering the unique undulation effect of water transportation on ships based on the N-S model, the concept of the marine sector is introduced; the original rules of acceleration and deceleration are improved; an updated CA model of appropriate single-channel as well as multi-channels on water transportation is put forward. With ship-following as the basis, for single channel of CA model on water transportation, distance between bows of ships is regarded as the determinant factor of conducting acceleration or deceleration; while for multi-channel CA model on water, on basis of channel changing model, analysis is made on the decisive role of overtaking, parallelizing and surpassing during the chasing process on acceleration and deceleration.3) Through an analysis on the current lockage status as well as existing problems of the Three Gorges Reservoir area, in addition to separate studies on the arrangement methods of two-channel ship locks and ship shift inclusive three-channel locks, by combination with highway toll station model, applied conditions for ship lift and ship lock scheduling principle, a dual-channel and multi-channel model of ship lock have been built, and an analysis on simulation results is given.4) Under the natural conditions such as fogs, floods, and low flow impact, corresponding characteristic functions of ship transportation organization mode are figured out, by combination with the current ship transportation mode, cellular automata models are built corresponding to the impact factors. With fog conditions, taking major considerations on the delay effect of drivers'visibility range on reactions to the ships in front, a ship transportation mode under fog conditions is constructed; while under the impact of floods, considering mainly the influence of water flow on the speed of ships and forces between ships, a ship transportation mode under floods is constructed; with low flow seasons, in view of the impact of less draft on the density of ships in the reservoir area, a shipping model under low flow seasons is designed.5) With the research background of passing the dam to the Three Gorges, an analysis is made on the flow characteristics of different kinds of goods. During the modeling process, definitions of cellular length are made according to characteristics of ships for major cargo species. With separations of goods suitable for road transportation from the cargoes through regular lockage, on basis of lockage model of ships discussed in Chapter4, transportation modes for specific cargoes are constructed and empirical studies are carried out on simulation models with historical data of the Three Gorges as the basis.The paper, regarding ships as cellular, makes simulations from a new perspective on the ship following, ship overtaking and ship lockage of regional transport organizations in the water transport hubs, not only expanding applications of the cellular automata theory, but more importantly deepening and improving the optimization theory of water transportation, which has provided scientific basis for the optimization of transportation modes on water transport areas, and is of realistic significance to reduce waiting time of ships or lockage and improve the lock capacity of water transportation hubs.