In a former paper the writer (T_AKAYAMA, S. 1956) mainly treated the problem of bed load transport. The present article describes the results of measurement on the transportation of suspended load of sediment by the three rivulets.
In Fig. 1 are presented writer's results of measurement of the suspended load on these rivers (Hayakawa, Fukôgawa and Ôkawa). Both the appreciable scatter of the points and the limited coverage of discharge range are evident. However, the trends of the regression lines indicate that suspended load discharge increases continuously with increasing discharge. The equations for the lines for average conditions of Hayakawa, Fukôgawa and Ôkawa are respectively:
Ha akawa; Q_S=114.1 Q^2•48
Fukôgawa; Q_S=89.9 Q^1•72
Ôkawa; Q_S=51.3 Q^2•06
in which Qs is the suspended load in tons per second, Q is the water discharge in cubic meter per second.
The coefficient and the exponent in the equations are different from each other due to the condition of the surface of the drainage area at the time, the rate of availability of sediments and other factors. Usually the suspended load seems to vary approximately as the square roots of the water discharge and this means that the values of increment of suspended load with water discharge is generally larger than that of bed load.
Two fairly distinct trends could be discerned (one for the flood occured August through September when high flows take place; the other for the flood of October when flood stage is not so high) from Fig. 1. This difference is thought to be due to the changing volume of fine-grained river bed material which can be easily transported. That is, the river bed is filled with fine-grained particles subsequent to several weeks of low stages; then the flood peak in August and September completely removes these particles.
Total sediment discharge is computed as the sum of suspended discharge and bed load discharge. It is the total quantity of sediment as measured by dry weight, that is discharged during a given time. For example, in Fig. 2, the area under the curves (Q_S-T and Q_B-T) represent the sum of suspended load [Q_S] and that of bed load [Q_B] respectively during a flood (Tab. 1) . Hydrograh for this flood is shown in Fig. 3. The percentage ratio of [Q_B] to [Q_S] (hereafter designated as Q_B/Q_S) varies with the scale of flooding as shown in Fig. 3. There is a tendency that the bed load movement dwindles to small portions as the maximum water discharge increases.
The gross amounts of sediment transported as bed load, suspended load and total sediment load during the observed period are calculated by continuous summation of [Q_B], [Q_S] and [Q_T] of each flood and Σ Q_B, Σ Q_S and Σ Q_T obtained as tabulated in Tab. 2. In order to provide data on comparative basis, these values are reduced to the values per square kilometer of drainage area. There are great spatial variations among them and these differences may be reflected not only in the character of sediment but also in the landforms themselves in each drainage area.
The geomorphic features which appear to be significant to sediment delivery are mean altitude of a drainage basin, maximum relief in a drainage area, mean watershed slope, mean channel slope and mean relief ratio (Fig. 4 & 5, Tab. 3).

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This paper is concerned with the problem on the regional pattern of urban traffic within Tokyo. With regard to this problem; considerable studies have been approached from a quantitative viewpoit, but urban structure seems to have been discussed separately. Thus, the author attempts to clarify the regional pattern of urban traffic from both qualitative and quantitative viewpoits and the relationships between urban traffic and urban structure. More precisely, the purposes of this reports are to clarify the regional of the gene-rated trips from both quantitative viewpoits, the relationships of the trips with population and land uses, and the directions of trips.
A survey was conducted in the following method: first, a questionnaire (Tab. 1) was prepared in order to search for the actual condition of urban traffic from a qualitative viewpoit; second, eighty-five primary school districts in Tokyo were selected by using the results of the preliminary survey in Shimoda, Shizuoka Pref.; third, fifty questionnaires were distributed to each district by the author.
As a result of analyzing the imformation which was collected from the questionnaires, the following points were made clear:
(1) Number of the generated trips in each district is closely related to the number of inhabitants in the district. The number of generated trips per inhabitant is smallest in the central part of Tokyo, and becomes greater toward peripheries. This difference is primarily due to the difference in the number of generated trips by persons without a job.
(2) In regard to the kind of trip purposes, persons with a job chiefly travel for commuting or working, while persons without a job chiefly travel for attending school or shopping. In residential areas trips for attending school, commuting and shopping are mostly generated, while in business, shopping and industrial areas those for working are generated for a most part.
(3) Destination distance of trips for attending school is short, and is longer as the trip person becomes a middle school pupil, a high school student, and a university student in turn. Destination distance of trips for commuting is the longest of all trips. Most of these trips in all districts are directed to the central part of Tokyo, but in eastern areas these trips to the central part are few and there may be a commuting area without strong connection with Tokyo's center. Destination distance of trips for shopping is the short-est of all trips and most of these trips are directed within the same district where they are generated. Trips for working are directed to two areas, that is, the same district where they are generated and the central area of Tokyo.

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In the previous study (Geographical Review of Japan. Vol. 31, No. 2, pp. 86_??_94, 1958), the author estimated the annual and seasonal maximum daily precipitations for 5, 10, 25, 50, and 100-year return periods by applying the Gumbel's theory. Using the estimated data, distribution maps of extreme values were constructed. But it was pointed out that the Gumbel's theory contained some questions. One of them is the fitness to actual distribution of extreme values. According to the works by Brooks, C. F. P. and N. Carruthers (1953), the extreme values of air temperature are liable to be overestimated and those of precipition understimated, if the Gumbel's theory is used. Jenkinson, A. F. (1955) presented an improved theory for the estimation of extreme values. This shows better fitness and the process of estimation is not so difficult. Hence the author reestimated the extreme values according to this theory for several return periods in Japan. The results at a number of stations were added to the previous works.
Regional distribution of the extreme values generally shows similar patterns to the previous maps (Fig. 2). Details of distribution, however, have some different features from the previous maps. The following facts were made clear in this paper:
1) The June-July season: heavy rainfall areas appear in western Kyûshu, southeaster part of Kii and entire part of the Izu peninsula.
2) The August-November season: heavy rainfall areas appear in the eastern Kyûshû, southeastern Kii peninsula, and northern and western Kantô.
3) The December-May season: an area with scanty rainfall appears in the coastal regions of Seto Inland Sea.
4) Year: heavy rainfall areas appear in southeastern and western Kyûshû and western Kantô, and an area with scanty rainfall inn the coastal regions of Seto Inland Sea.
The author compared the estimated extreme values of the June-July season with those of the August November season. Heavy rainfalls in the June-July season are mainly caused frontal activities (Bai-u), and those in the August-November season are by typhoons. At stations where the estimated values in the June-July season are larger than those in the August-November season, fronal rainfall is distinctly heavier than typhoon rainfall. On the contrary, at stations where the estimated values in the August-November season are larger than those in June-July, typhoon rainfall is heavier than frontal rainfall. The author calculated the ratio of the extreme values in the June-July season to those in the August-November season for each station. At the stations with the ratio exceeding 1. 0, frontal rainfall is predominant, whereas typhoon rainfall is abundant at the stations with the ratio below 1.0. Areas with the ratio exceeding 1.0 are concentrated in the following districts (Bai-u areas):
1) Northern and western Kyûshû,
2) Chûgoku (except eastern San'in),
3) Western Shikoku,
4) Middle Kinki,
5) Hokuriku.
Areas where the stations with the ratio less than 1.0 are concentrated are the following districts (typhoon areas):
1) Eastern Kyûkhû,
2) Eastern Shikoku,
3) Northern and southwestern Kinki,
4) Western Kantô and Izu islands,
5) Eastern Ôu,
6) Northeartern Hokkaidô.
Based on these facts, Bai-u and Typhoon areas can be distinguished in Japan.
Lastly, the author made clear the regionalities that a found in the secular changes of maximum . daily precipitation in each season. He divided the trends of secular change into the following three types: increasing (type 1), decreasing (type 2), and indefinite trend (type 3).
Thg results are as follows:
1. The June-July season.
1) Type 1 is distributed all over the country, except a few districts.
2) Type 2 is concentrated in the inland areas of Chûbu and in Hokuriku.
2. The August-November season.

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Most of the reports on landslides have described about the length, width, inclination of the slope and other components which serve to give general information upon the extent of landslide. However, no detailed discussins on the extent of landslide have been made, so far as the author is aware of, except that in the work of F. O. Jones et al. Of the components concerns this paper mainly with the length, width and scarp height components by which some discussions on the development of landslide area are made. These components of each landslide were measured either from topographic maps or from field observations. Twenty six landslides were examined in Higashi-Kubiki and Uonuma Mountains, Niigata Prefecture, where many landslides have occurred.
The length component is the horizontal distance from the toe of the landslide to the crown as taken in the direction of maximum inclination at midsection of the slide. The width component is the average horizontal distance from side to side across the slope of the slide. The scarp height component is the maximum difference in altitude between the foot of the scarp and the crown as taken in the direction of the slope. As the foot of the scarp was frequently obscured by tales deposits, determination of its position was made at the topographic breakpoint. The data of scarp height, therefore, are somewhat low in reliability.
The results obtained are shown in the table and figures.
The conclusions to be drawn are as follows:
(1) A unit landslide (landslide formed by one sliding) seems to be shorter than 240 meters in length.
(2) Landslides range from several decades of meters to 1360 meters in lengh, and their lenght and width tend to be larger as they regress.
(3) At the early stage of the development of landslide its position is at foot of the valley wall slope and the ratio of length to width is smaller than that of the later stage.
(4) The scarp height increases with regression of the landslide. But when the crown of the landslide reaches to the ridge, altitude of the ridge is lowered and so the height of the scarp is reduced again.

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