In the previous paper, the author analysed the local wind systems in central Japan in winter, from the viewpoint of synoptic climatology, and described their distribution in detail, whose pattern mainly changed corresponding to gradient wind direction and velocity. However, northerly or westerly flow patterns usually prevail over the area in the winter season, and consequently the state of the surface wind systems in the southerly flow pattern could not be obtained.
The author is going to discuss this problem in the present paper. The method of arrange-ment of the data is the same as in the previous paper. Firstly, thirty days were selected in the warm season by the following criteria: that the gradient wind blows from a southerly dir-ection at a speed exceeding 10m/s on the surface weather chart, and that the disturbances do not directly affect the area for the whole day. The wind and weather data of about 600 clima-tological stations were inscribed on the maps and the streamlines delineated at 9 a. m. each day. A typical example is shown in Fig. 1. The station is identified by a circle and cloud cover is represented by the symbol adopted by the World Meteorological Organization. The wind is indicated by arrows and the wind force barbs according to the Beauf ort scale.
Local wind systems are clearly perceived in various parts of these maps. Especially, south-erly or southwesterly airstreams prevail all along the coast. However, topography features on a meso- or macro-scale, such as mountains, peninsulas, valleys and bays, affect not only the airflow pattern, but weather distribution. For instance, southerly wind, the so-called f oehn, observed in the I-Iokuriku District along the Sea of Japan, is dry and strong, and develops down the lee slope of the mountain range and becomes strongest at the mountain foot, above all at the apex of the fan. Moreover, a clear sky is frequently observed in the lee area, though extensive areas with cloud cover tend to spread over the windward side of the mountain slope.
This example shows the most common wind distribution in the southwesterly flow pattern, though, of course, the above-mentioned distribution maps of wind direction are slightly differ ent from each other. Generally speaking, the pattern of wind distribution on these maps is more complicated than that in winter, because the surface wind systems are indirectly influ-enced by disturbances, such as cyclone and front. However, when the gradient wind on the surface weather chart is 180° to 240° and its speed exceeds lOm/s, the maps of streamlines show a similar pattern to each other as shown in Fig. 1 (Wind direction is represented in degrees as measured clockwise from due north.) This flow pattern occurs when an extra-tropical cyclone advances eastward over the northern Japan Sea and Central Japan lies in the rear of a migratory high. This flow pattern is denoted by Type V in accordance with the classification of Types in the previous paper. The other flow patterns in the warm season, such as the southeasterly one, were not analysed in that paper, because their frequency is relatively low and the above-mentioned pattern is dominant.
In order to represent schematically the distribution of the surface wind systems for Type V, a composite map of the surface wind distribution was made in the same manner as in the previous paper. Twenty examples were selected for this purpose, which are comprised in the above-cited category. Results are illustrated in Fig. 2. Streamlines of the surface wind are drawn with solid arrows. Broken arrows, however, are used instead in some areas, where the surface wind is so weak or the climatological stations are so sparse that the streamlines are difficult to ascertain, especially owing to their being located at valley bottoms in a mountainous region. Hatched and dotted areas indicate areas with strong and weak wind respectively.

View full abstract

Wave-cut benches developed along the coast of the Miura Peninsula (Fig. 1) were uplifted at the time of the Great Kanto Earthquake in 1923. The amount of the uplift was estimated at about 1.4m. Wave-cut benches in the studied area (Fig. 2) are composed of steeply inclined Miocene strata of rhythmic alternation of tuff and mudstone; the strata strike about N 60 E and dip about 70 S (Fig. 3 and 4). On the surface of the benches, washboard-like relief is observed ; the relief attains a relative height of 5-300cm. There always exist tuff layers in ridges of the relief; on the other hand, furrows are of mudstone layers (Fig. 4). Numerous minor joints develop on the surface of mudstone layers as compared with tuff ones. The field observation proves that the joint development in mudstone is obviously due not to tectonic deformation but to weathering.
Figure 5 a gives a definition sketch, where H is the greater of the two relative heights of one ridge, A the thickness of a tuff layer, and D the thickness of the whole strata con-stituting the ridge. Figure 5 b shows the relationship between I-I and A, for various A/D; the relative height of ridges increases in proportion to the thickness of tuff layers making them up. Then, the authors examined the relationship between the greater of the two relative heights of one ridge (H) and the interval to adjoining ridges (L) (Fig. 6 a), ignoring ridges where the thickness of tuff layers is less than 20cm. Figure 6 b shows that H increases as L is increased, in other words, the degree of depression of furrows increases in proportion to the thickness of mudstone layers. Figures 5 b and 6 b prove that the kind and thickness of layers control the washboard-like relief on the surface of the benches.
In order to clarify the mechanism of the washboard-like relief formation, first of all, the authors examined physical and mechanical properties of tuff and mudstone in various states. Table 1 gives physical properties of both rocks. Figure 7 indicates the relationship between the unconfined compressive strength (hereafter referred to as the “compressive strength”) and the water content of specimens. The compressive strength decreases with the increase of the water content; the strength of mudstone is about two times as great as that of tuff for any water content. Table 2 shows that propagation velocity of longitudinal waves (Vp) in mudstone is higher than that in tuff, regardless of their direction to the bedding planes. The results mean that tuff is more porous and weaker than mudstone, and they consist qualitatively with the results of a compression test (Fig. 7). Table 3 shows the results of a wear test by using the Los Angels abrasion machine. Wear in a mill of this machine is produced by both abrasion and impact, so that the results represent not only the abrasive hardness and impact strength of rocks, The abrasive hardness and impact strength of mudstone are much greater than those of tuff, regardless of the water content of specimens. The aforementioned strength such as the compressive strength, the abrasive hardness and the impact strength implies the strength or resistibility of rocks against external forces, and these results prove that mudstone is stronger than tuff. It has been considered in Geomorphology, in general, that “strong” or “hard” rocks remain uneroded and then protrusive. In the present studied area, on the contrary, ridges, or protrusive parts, are of tuff which is weaker or softer than mudstone constituting furrows, or depressed parts. Therefore, it is impossible to explain, in terms of the geomorphological concept as mentioned above, the formation of the washboard-ike relief in question.

View full abstract

This study is what I tried to clarify the entity and the relation with the environment by approaching through geographical situation about traffic accidents ranked the fifth in the death-order by causes, which became one of the serious and social problems in Japan recently. At this time, however, it is a macroscopic study mainly. The conclusion can be completed on the whole as follows.
1. About the national traffic accidents (the number of occurrence, dead number, and wounded number), the number of motorcars, the population, and the number of cities, looking at the transition by years, it is obvious that each factor is in the tendency maintaining the proportional relation mutually. Above all we can affirm the tendency which the population and number of motorcars induce traffic accidents restraining one another. Thus we can recognize what the population and number of motorcars are two essential factors on traffic accidents. Comparing the two, the number of motorcars is some stronger than the population in influence. So the actual number of accidents increases with increasing of the population and number of motorcars, nevertheless the accident number per ten thousand cars decreases yearly. It is founded on restraining by another factor, the population is increasing gradually. On the contrary, the accident number per hundred thousand persons increases yearly. It should interpret that it is founded on restraining by another factor, the number of motorcars is increasing rapidly (cf. Tab. 1, Tab. 2, Fig. 1, Fig. 2).
2. Examing the stenotypes of the accidents on the road occupying the majority in traffic accidents of our country, the case of colliding with pedestrians and motorcars is the highest rank. The case of bicycles versus motorcars is the fourth, but it is a pretty high rate as it reaches over 10%. While the first rank in U.S.A. is the case of motorcars versus motorcars. And the case of bicycles is only the degree of 1%. It is thought that our country is reflected the peculiar condition jostled each other at the narrow space (road) with pedestrians, motorcars, and bicycles from the difference. Next, in traffic accidents by causes, the case of “a violation against safety operation duty” in the side of motorcars is the highest. While the case jumped out suddenly on the road in the side of pedestrians is the highest. It seems that these cases are closely connected with the defective roads in our country. For example, there are very numerous roads as follows; irregularly meandering roads, blind alleys, and narrow lanes et cetera. Besides the safety equipments (the distinctions between the footpath and driveway, and others) and not enough yet. There are these conditions as the backgrounds inducing easily the sterotypes and causes above-mentioned in our country (cf. Tab. 3, Tab. 4).
3. Investigating the occurrence by months of traffic accidents, it becomes the highest in August of a high temperature and humidity, and the lowest in January and February of a low temperature. Notwithstanding the traffic stagnancy belongs to the rather lowest among twelve months. So these facts had better think of inducing due to the climatic influence. Namely the sultry climate like the summer in Japan exerts physiologically bad influences to the drivers and pedestrians. Conseqently the summer in Japan is unfavorable as for the occurrence of accidents. Furthermore, in the relation of the condition on the daily weather and the occurrence of traffic accidents in Tokyo, we can recognize the tendency which the accidents occur compara- tively numerously on the rainy and foggy days. On these days, it is thought that the accidents increase to resemble roads of an imperfect equipment and the condition of the dark nighttime because motorcars slip easily or become narrow visibility (cf. Tab. 5, Fig. 3, Tab. 6, Fig. 4, Tab. 7).

View full abstract