A study of the residential structure of the American city has produced an increasing literature under the technique of factorial ecology. The study of large cities however is not enough compared to that of smaller cities because of the labor dealing vast information when taken a small area like a census tract as a observation unit. The auther investigated the residential structure and its spatial pattern for the Detroit metropolitan area by performing factor analysis upon 1960 and 1970 census data. Change in the structure and pattern is also studied by comparing the extracted factors and factor scores obtained at different points in time. The area studied is the entire Detroit Standard Metropolitan Statistical Area. (Fig. 1) The census tract is employed as a observation unit. After omission and consolidation a total of 762 tracts constitutes the analysis in 1960 and 986 in 1970. 56 variables from population characteristics available in the U.S. census of population were selected for the study. (Table 1) The same variables were chosen in the analysis for both 1960 and 1970. They are classified into 10 major categories: (1) sex and age, (2) family and household, (3) marrige status, (4) race and ethnicity, (5) mobility, (6) labor force, (7) occupation, (8) working status, (9) education and (10) family income. Product-moment correlation coefficients were computed for all variables. These matrixes were then subjected to principal factor method factor analysis. Eight factors were extracted in 1960 and nine in 1970, accounting cumulatively for 83% and 81% of the total variance respectively. Those factors were rotated to orthogonally to simple structure. Varimax rotation was employed. The matrixes of factor loadings are shown in Tables 2 and 3. The 1960 factors were interpreted as follows: (I) Family Life Cycle, (II) Racial Composition, (III) Socio-economic Status, (IV) Women in Labor Force, (V) Eastern European Immigrants, (VI) Youth Predominance, (VII) Sexual Composition and (VIII) Italians. The first three factors accounted cumulatively for more than 60% of the total variance and there was a sizable difference in significance between each of them and each of the rest. The 1970 factors were interpreted as follows: (I) Socio-economic Status, (II) Racial Composition, (III) Family Life Cycle, (IV) Women in Labor Force, (V) Residential Mobility, (VI) Eastern Europian Immigrants, (VIII) Sexual Composition, (IX) Youth Predominance/Italians. The first three factors were also observed as significant and accounted for about 58% of the total variance. In order to test the relationship between 1960 and 1970 factors, correlation coefficients were calculated and are shown in Table 4. Factor I in 1960 has strong correlation to Factor III in 1970, Factor II in 1960 to Factor II in 1970, and Factor III in 1960 to Factor I in 1970. Therefore it was confirmed that the first three factors of both years, which were Socio-economic Status, Racial Composition and Family Life Cycle were the major stable factors that explain the residential differentiation of Detroit. Minor factors of each year do not correspond clearly with each other except the factors of Women in Labor Force and East European Immigrants, which are considered to be the stable minor factors. The spatial patterns of the major three factors were then analysed. Prior to it the entire metropolitan area was devided into seven concentric zones numbered 1 through 7 from the C.B.D. outward and seven sectors numbered 1 through 7 from southwest to northeast, which made 49 cells. (Fig. 2) The spatial patterns of factor score distributions were examined by three steps. First, a series of analysis of variance were undertaken to judge objectively whether the factor score distributions of Socio-economic Status and Family Life Cycle correspond to concentric model or sector model.
There is the historical relic of the grand canal so-called “Furuichi-ohmizo” in Minamikawachi county of Osaka prefecture, where it belongs to the region of the ancient tumuli: Furuichi-Kohun-group. “Furuichi-ohmizo” coexists with these ancient tumuli. It is considered as the big canal which was artificially cut in ancient times. However, the part which “Furuichi-ohmizo” survives is very little, the whole aspect is not yet evident. It is the purpose of this paper to reconstruct the whole canal in detail, and to clear up its character. In this case, the author used the geomorphological and palynological research method in order to investigate the ancient geomorphological and vegetational environment. The results are as follows: 1. Ninken-ryo, Minegatsuka-kohun and Seinei-ryo are situated in the vicinity of the mouth of the erosional valleys. (Ryo means the mausoleum of emperor. Kohun means the mausoleum of emperor or powerful family.) They were built in the place of the bad condition. It can be considered that these ancient tumuli were built to bring water of the valley to the moat. 2. The sand bed at the upper stratum of the silt bed is accumulated in the flood plain at the junction of the Yamato-gawa River and its branch: the Ishi-kawa River. Such change of sedimentary environment depends on the change of the channel of the Yamato-gawa River. This is an example that the change of the river channel greatly influences the formation of the flood plain. 3. By means of the geomorphological investigation and the examination of the placename Koaza in cadastre, the author could reconstruct the canal of the ancient “Furuichi-ohmizo” in the map. As a result, it became clear that “Furuichi-ohmizo” was a big artificial canal from the Ishi-kawa River to the Higashiyoke-gawa River. “Furuichi-ohmizo” formed the one part of the ancient network of canal which was divided into the two main canals and it had some branch canals that linked these main lines. However, it is uncertain whether these canals were built in the same times or not. 4. The artificial depression in the west of Shiroyama-kohun exists at the junction of the two main canals. This depression intersects with Ohtsu-michi. The placenames of Koaza as “Kamiohhune”, “Shimoohhune” and “Irimizu” in this place suggest this intersection. Further, it is remarked that the canal crosses the middle terrace. According to these facts, we can infer that the artificial depression is possible to be a port, and the canal was used by way of the water transportation. 5. The vegetation in this area changed in the period of early 8th century to early 12th century. The result of the pollen analysis shows it clearly. That is, the forest which was characterized by Abies, Tsuga, Cryptomeria, Sciadopitys, Cyclobalanopsis and Quercus destroyed, changed to the forest of Pinus. And Gramineae increased suddenly before such vegetational destruction. It shows that the clearance of the terrace was faster than the forest destruction of the mountain. The pollen of the large type of Gramineae and Fagopyrum which were the cultivated plant doesn't appear on the lowest pollen zone, it seems that the terrace was not developed at the age of the lowest pollen zone. Therefore, it is assumed that “Furuichi-ohmizo” was used firstly not as the irrigation canal but as the water transportation.