Study on Optimizing Airport Runway Design by Economic Analysis

A rapid increase of air traffic is anticipated by the main airports in Japan. The existing airport facilities of the main airports in Japan are already thought to be insufficient, and it is earnestly requested that these facilities will be reinforced as urgently as possible. It is vital that we determine the ultimate runway capacity to make a plan more accurately for long range development of adequate airport facilities on a schedule which will meet the projected increase in air traffic. Mathematical models have been developed that can be used in forecasting the operating rates of runways with associated delays. These models have been devised covering delays under preemptive priority type operations. The optimum runway design is that which will manage to keep the balance between operating cost and total annual costs of runway. The optimum design then is determined by the economic analysis of the factors that affect runway operations. Economic analysis have been developed that could be used in determining the break-even volume for the improvement of runways

Identification and Prediction for the Long Range Runoff Systems

In this paper, the runoff simulation method has been discussed in order to obtain effective information for water resource planning. The framework consists of the identification of the long range runoff systems and the simulation for the areal daily precipitation while the runoff data are simulated by their combination. First, for identifying the long range runoff systems, the improved statistical unit hydrograph method is proposed based on the techniques of information theory. Next, the daily precipitation data are simulated over a long period and in a wide area through the successive combination of regional correlation analysis between the base or sub-base and surrounding stations, spatial simulation between the base and sub-base stations, and sequential simulation at the base station. Finally, by the combination of the improved statistical unit hydrograph method and the simulation method for areal daily precipitation, the observed data are shown with sufficient accuracy

On the Effect of Sand Storm in Controlling the Mouth of the Kiku River

As the mouth of the Kiku River flowing into the Sea of Ensyū always moves, being blockaded in some cases, due to the sand-drift in the sea and on the coast by monsoons in winter, the raised water level in the river mouth gives unfavorable effects to the upstream side of the river. Therefore, the control project to maintain the river mouth and prevent it from blockading is becoming a pending problem of the river. It is very difficult to solve this kind of problem satisfactorily, and it is necessary to start fundamental researches in order to obtain a clue to settle this problem. Thus, in this paper, we tackled the effect of sand storm on the coast by wind, that is, estimating the sand quantity moved by sand storm in a year based on the data of wind-velocity, -direction and rainfall, we discussed the effect of sand storm on the movement and blockade of the river mouth from the point of view of civil engineering

Some Studies on Beach Erosions

For some years now the writers have engaged in the field study on some important topics of beach erosions. The purport of this paper is to report briefly the main results obtained therein. Following an introduction, in Chapter 2, wave observations made along the beaches of Toyama Bay and of Ise Bay around Tsu City are described. The observed breaker heights were well explained by the effect of wave refraction. From the wave observations made along the beach of Tsu City, it was further suggested that the mean wave energy is proportional to breaker heights just at the moment of breaking. In Chapter 3 another factor which causes, besides the wave refraction, the distribution of breaker heights, that is, the effect of fetch, is discussed along the southern beaches of the east coast of Ōsaka Bay, and it was suggested that for the beach erosion of this region the effect of fetch played an important role. In Chapter 4, the grain size distributions of the beach sediments together with the beach profiles along the same beaches in Chapter 2, are discussed. From the sand ridge towards the shore the beach profile has two distinct slopes, the one corresponding to the surf zone, the other corresponding to the up-rush zone--a zone over which the breakers at the shore rush up after breaking. The grain size of the sediments increases rapidly in the surf zone towards the shore and in the up-rush zone it becomes abruptly large. It was noticed that different hydraulics must be applied to these two zones. In Chapter 5, the results of wave observations at the beach of Sano City along the same coast in the previous chapters are described. The wave profiles were recorded simultaneously with the particle velocity associated with a wave by the wave profile recorder and current recorder. Two distinct types of breakers were found, one which is called flow type has the maximum of velocity in the fore side of a wave, and seems to develop to a bore after breaking, while the other which is called wave type has the maximum of velocity at the crest of a wave and seems to crush after breaking. These two types of breakers are compared with the results of wave observations made in a wave tank. In Chapter 6, some results of observations of the sediment transportation along the up-rush zone at the same beach are described. It was found that for the breakers of flow type the net transfer of sediments is on-shore, that is, beach sedimentation takes place, whereas for the breakers of wave type the net transfer of sediments is off-shore, that is, beach erosion takes place