The Tokachi Plain is located on the eastern side of the Hidaka Range, the back-bone of Hokkaido, where a number of glacial landforms are well preserved (Fig.1). It has long been pointed out that the Tokachi Plain is one of the most important region for the Quaternary research in Japan. Widely developed alluvial fans at the foot of the Hidaka Range, an alluvial plain in the lowest reach of the Tokachi River and marine terraces along the Pacific coast are no less stimulative for geomorphologists than the glacial topographies in the Range.
In this paper, the authors discussed the landform evolution of the Tokachi Plain in order to clarify (1) the relation between the construction of alluvial fans in the Plain and the glaciatin in the Range, and (2) the relation between fluvial terraces and marine terraces indicating sea level changes in the late Quaternary. The surfaces of these terraces are covered with tephra layers, to which the authors refer as the Tokachi Loam (Fig.2). Key beds of characteristic pumice or scoria layers in the Tokachi Loam and continuity of terrace surfaces lead to a classification of the fluvial and marine terra ces (Table 1, Fig.3) and their chronological arrangement (Fig. 8).
Of the marine terraces, the O II surface consisting of thick marine deposits seems to have been built under the heighest sea level in the Eemian Interglacial age. The 0 IV surface shows a slight transgression at about 60, 000 years P. P.. Consequently, the fluvial surfaces younger than the 0 IV surface are included in the Warm Glacial and Postglacial ages. From the view point of the landform evolution, at least three phases are recognized in these ages as described below.
(1) 60, 000 30, 000 Tears B. P.
Valley filling and expansion of alluvial fans were conspicuous in the Plain; the Ko I filltop terrace surface was formed just before the fall of Spfa (Sh.ikotsu Pumice Fall Deposits).
(2) 30, 000.10, 000 years B. P.
Neither deposition nor downcutting were remarkable in the area of alluvial fans. The alluvial fans of the Ko II and Ko gj surfaces were constructed as strath terrace surfaces in rather limited areas compared to the former Ko I surface. Whereas in the lowest reach of the Tokachi River, deep incision, which was caused by a regression reaching about 1.20 m below sea level at the maximum, resulted in a steeper gradient of the longitudinal profile of the Ko II surface (Fig.7).
(3) 10, 000 years B. P.-Present
In the area of alluvial fans vigorous incision reaching 20 to 50 m in depth took place ; alluvial fans and river terraces of the Ko I, II and f surfaces were cut down to form many strath terraces of the Ko IV surfaces. While in the lowest reach, of the Tokachi River, the Postglacial transgression caused deposition of thick alluvium to bury the surfaces of Ko I-Ko II (Fig.7).
The glacial landforms in the Hidaka Range, consisting of cirques and moraines, are either younger and fresh or older and dissected. The distribution of the older ones is much extensive than the younger. Contrary to the generally held view that the older landforms are correlated to the Kiss Glacial in age, the authors are of opinion that they are rather correlated to the early stadial of Wurm Glacial age. The moraines and out-wash deposits of the older stadial (Poroshiri Stadial) are probably correlated to the fill gravels of the Ko I surface. And those of the younger stadial (Tottabetsu Stadial) are probably correlated to the deposits of Ko II surface.
It can be concluded that the la.ndform evolution of the Tokachi Plain has been controlled by the sea level changes in the lowest reach of the Tokachi River and by the climatic changes in the alluvial fan areas or the upper reaches.

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The stability of slopes is controlled by many factors such as landform, geology and vegetation. The relations between these factors and the slopestability have been dis-cussed by many authors. Most off these discussions, however, are qualitative in method. Therefore, it is difficult to compare the degrees of influence exerted by each factor upon the slopestability. Moreover, it is not easy to estimate the stability of each slope on the basis of the total influence of these factors. The present author, therefore, tried to quantify and to compare the degrees of influence of these factors upon the slopestabi-lity. In this paper, the degree of influence upon the slopestability is computed as the rate of contribution to the discrimination of the unstable slopes and the stable ones.
The six factors, that is, vertical type of slope, horizontal type of slope, the maximum slopeangle, vegetation, geology and relief energy are examined here. Each factor is divided into a number of categories as shown in Table 1.
The criteria concerned with the discrimination of the slopestability are as follows
Unstable slopes; slopes where ruptures (land collapses) have occurred in recent years, i.e., slopes where active ruptures or the visible traces of old ruptures in recent years are existent.
Stable slopes; slopes where there is no ruptrue.
The geomorphological survey map (Fig.5) is covered with a grid of 200 m. 297 meshes are sampled at random from the meshes where the unstable slopes are existent and 248 meshes from the meshes which consist of only the stable slopes. The categories of every factor are read at each mesh by means of the maximum area method.
The numerals of the categories are expressed in the nominal scale. Then, it is necessary that these numerals are converted into the values of the interval scale con-nected with the slopestability. This means the quantification of the influences of the categories upon the slopestability. For this quantification, the following equation is used
_??_
where Xj=the intra-factor weight of j-category (the degree of the influence of j-category upon the slopestability),
f1.j=frequency of j-category of the unstable group,
f2.j=frequency of j-category of the stable group,
q=number of categories of the factor,
C=a given constant.
The calculated Xj are shown in Table 4 and Fig.7. The intra-factor weight of the category means the relative degree of influence of the category upon the slope-stability among the categories of each factor.
The weights of the factors shown in Table 6 indicate the relative degree of in-fluence upon the slopestability among the factors. These weights are calculated by means of the discrimiriant function- The weights of the factors become smaller in order of geology, relief energy, the maximum slopeangle, vegetation, horizontal type of slope and vertical type of slope.
The products of the intra-factor weights of the categories and the weights of the factors to which the categories belong are the generalized weights of the categories (Table 8 and Fig. 11). These generalized weights of the categories mean the relative degree of influence of the categories upon the slopestability among all of the categories. These weights are used in the discrimination of the slopestability of every mesh on the basis of the total weights of six factors.
The intra-factor weights of the categories, the weights of the factors and the gene-ralized weights of the categories calculated in this paper are not inconsistent with the tendency pointed out qualitatively by many authors. And the result of the discrimina-tion of the slopestability of each mesh in the studied area indicates that each type of the weights examined in this paper is considered to be appropriate for the estimation of the slopestability.

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Per capita waer use is one of the most important variables in the evaluation of amounts of water consumption and in the planning of water supply systems. The estimating procedures, that have hitherto been adopted in the past Japanese studies dealing with municiplities, are far from being justifiable. This paper discusses problems on the estimate of per capita water use, based on a case study of IchiharaShi, Chiba Prefecture.
In conclusion, the follwings are emphasized for the detailed estimate of per capita water use: municipal water demands depend on the two sorts of water users, that is, residential users and users who consume a large quantity of water such as public baths, hotels, big stores and industries. These two should clearly be differentiated from each other in studies on municipal water demands. It is of importance that per capita water use is estimated on the basis of amounts of water used for just residential purposes.

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