Although Seoul is the third largest city in the world (1982), only one investigation has been performed on its heat island (Lee and Kim, 1979). However, they made clear the characteristics of horizontal temperature distribution on calm and clear evenings by case study.
Then, the author focused on (a) the features of the heat island under various weather conditions and times and (b) the correlation of various indices which affect the urban heat island form at ions. These indices include land-use types, the ratio of impermeable surface coverage related to them, and the concentration of air pollution (SO₂).
The study area includes Seoul (8, 400, 000 population) and its four satellite cities, Seongnam (380, 000), Kwangmyung (150, 000), Euijeongbu (140, 000) and Shindo (60, 000). Seoul is located in a basin surrounded by mountains approximately 250-830 m high. The urban area of Seoul extends radially along four main streets and the Han River flows through the southern part of the city (Fig. 1.).
Temperature observation was made by an automobile and other meteorological data such as, cloud cover, wind direction and wind speed were provided by the Seoul Central Meteorological Office. The series of observation by car were repeated along three routes A-B, C-D, and E -F (shown in Fig. 1.), eleven times during each of three time periods: early morning (04:00-05:30), day time (14:00-15:30), and night (22:00-23:30) from June to August, 1982, for a total of 99 runs. The number of observation points along the three routes totaled 134. Table 1 describes the experimental program.
For the illustration of mean horizontal temperature distribution under typical condition, limited sets of observation which were carried out on clear and calm nights were chosen, and the temperature deviation at each point from the mean route temperature (T-T_route) are calculated as shown in Fig. 2. Positive deviation approximately corresponded to the built-up areas within a 10 km-radius from the center (CBD) of Seoul and that in satellite cities. On the other hand, cool regions appeared in the rural area outside of Seoul. Especially, a cool pocket was found over an island in the Han River.
The higher temperature deviation area had the lower standard deviation and the lower temperature deviation area had the greater standard deviation in most cases. Variations of temperature deviations caused by weather conditions (cloud cover) and different times in Seoul CBD were less than those in suburban area. Gradients of the temperature deviation tended to change significantly at the boundaries between the built-up area and rural region (Figs. 3 and 4).
The heat island intensity (difference between the highest urban temperature and the lowest rural temperature, ΔT_u-r) on clear days (cloud cover<7/10) was greater than that on cloudy and rainy days (cloud cover>8/10) and it was the greatest from night to early morning and less in daytime. The values of the maximum heat island intensity of Seoul were 7.1°C (the maximum value) and 3.7°C (mean for clear night observations) (Table 2).
Wind speed was the main determining factor for the heat island intensity and it affected the distribution of the heat island (Fig. 5). The heat island intensity was destroyed above a critical wind speed of 11.8 ms^-1 for Seoul and decreased with decreasing urban population (Table 3).
To analyze the relationship between surface coverage based on the land-use types and the urban heat island phenomenon, an analysis was done by using a multiple regression analysis. The study area was divided into a 0.5×0.5km square grid and then the areal ratio (%) of the land-use types within each grid was measured. The prevailing land-use types in the city outskirts, i.e, green belt, agricultural area and water surface played an important role in lowering the urban temperature.

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Cultivation on the arable land, lumbering and gathering in the mountain, and livestock raising both in the farmland and forest combine to characterize the way of living in the northern Kitakami Mountains of northeastern Japan. Yamagata Village being our study area, this paper attempts to examine the transition of such complex economic activities and the transformation of mountain resource utilization, and then to analyze the characteristics of diversified farming with livestock as well as their regional variations with special reference to the resource utilization complex. Our findings are summarized as follows:
1. In the present-day Kunohe County, to which Yamagata Village belongs, horses had long been raised as draft animals and chargers, while cattle had also been kept to transport iron ore and charcoal for iron processing. Mountains not only provided firewood and charcoal, but also were utilized as hay field and pasture. On the arable land, usually fertilized by barnyard manure, soybeans, wheat or barley, and Japanese millet were cultivated to provide subsistence food and feed. To obtain cash income, farmers seasonally migrated out of the village to obtain employment in Sendai and other cities. In the Meiji era when landownership became clearly established by the new government, forests fell into either national or private possession. In the northern part of Yamagata Village, jitou, the head of each settlement, obtained the title to the mountains which had previously been used as commons, with the obligation of paying land taxes. Farmers, on the other hand, had to provide the head with labor in return for the use of the mountain. Mountains in the southern part of the village were nationalized.
2. From the Taisho era to the early part of Showa, improvement of transportation conditions substantially stimulated lumbering. The traditional system of three croppings in two years was still practiced. While mountains were variously utilized as grassland and for charcoal and timber extraction, competition began to occur among different types of utilization. After World War II, horses disappeared while cattle increased. On the arable land, feed crops including dent corn augmented, taking the place of Japanese millet, wheat and soybeans. Although dairy farming and various commercial crops were introduced in recent years, cattle breeding became the pivot of agricultural activities. In the mountain improved pasture expanded and afforestation proceeded. With the expanding feed production, the utilization of mountains became increasingly differentiated. In the high growth period of Japanese economy, a number of seasonal migrants headed for the Kanto region, while i n the mountain, with the declining charcoal production, villagers became more and more engaged in wage labor in forestry.
3. The above-mentioned process of transformation had regional variations in Yamagata Village. Changes were more clearly observed in the northern part than the south. In Uchimagi settlement in the southern part of the village surrounded by the national forest, traditional crops such as Japanese millet, wheat and soybeans, are still cultivated and cattle are grazed on the natural pasture and during the summer in the national forest. In Tsunagi in the middle-eastern part of the village where most forests belong to large private landownerships, dent corn cultivation for feed is gaining in importance among traditional subsistence crops. Cattle are grazed on natural pasture, while farmers have right of using the grazing field in the neighboring municipality. Cash income is obtained by engaging in wage labor in forestry and construction works. Seasonal migration to Kanto is also observed. Ohminesawa in the northern part, where farmers possess farely large forest among large mountain holdings, has the substantial acreage of dent corn together with other commercial crops.

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In this paper the author discusses thee vertical changes in the distribution of morphocli-matic zones from the Last Glacial Stage to the Post-Glacial Age on the basis of the fossil periglacial slopes and nivation hollows observed in the Mikuni Mountains, Central Japan.
The fossil periglacial smooth` slopes and nivation hollows were formed during the period from ; the Last Glacial Stage to the Post-Glacial Age. The former are convexo-concavo slopes not having a free face at their head unlike a talus. The latter are shallow depressions often located on gentle slopes near: ridges. The lower limits of their distribution are in general 1, 300-1, 400m a. s. 1. The slope mater ial mainly consists of angular-subangular gravel with a fine matrix covered with kuroboku and/or peaty soil. Its texture is characterized by vertical sorting and a fabric in which the long axis of individual gravels tends to be aligned in the same direction as local gradient: of surface slopes but less steeply inclined. These features suggest that they are solifluction deposits. In details, cross laminations are sometimes observed in the slope material beneath the fossil nivation hollows, indicating that rapid solifluction and slopewash operated on its movement.
At some sites of the fossil periglacial slopes and nivation hollows, angular-subangular gravel beds with openwork texture intervene in the slope material. The long axes of the gravel show slightly isotropic and/or oblique orientation to local gradient of surface slopes. This fact indicates that the gravel are almost autochthonous or that small-scale rockfall and rolling down operated on their movement.
The kuroboku and peaty soil usually contain Kikai -Akahoya ash-fall deposit (Ah, ca. 6, 300 y. B. P.) even at the summits (ca. 2, 000m a. s. 1.) . At the area lower than 1, 600 1, 750m a s. 1., the slope material and bedrock are often overlain by Tsumagoi pumice fall deposit (YPk, ca. 11, 000 y. B. P.) and the fine matrix of the slope material contains Aira-Tanzawa ash-fall deposit (AT, ca. 21, 500 y. B. P.). But the matrix of the slope material often contains a great number of “YPk” pumice grains in the area higher than 1, 600-1, 750m a, s.1. From these observations the succession of slope development in the Mikuni Mountains from the Last Glacial Stage to the Post-Glacial Age is inferred as follows;
During the Last Glacial Stage before the fall of “YPk”, periglacial smooth slopes and nivation hollows had been formed zonally in the area higher than ca. 1, 300-1, 400m a. s. 1. The vegetation was very poor at that time and it was much colder than the present.
The lower limits of the area covered with perigalcial smooth slopes and nivation hollows had risen since the late stage of the Last Glacial Age. Periglacial smooth slopes and nivation hollows were restricted in the area higher than 1, 600-1, 750m a. s. 1. around the age of “YPk” fall (ca. 11, 000 y. B. P.).
At the age of “Ah” fall (ca. 6, 300 y. B. P.), the formation of periglacial smooth slopes and nivation hollows ceased in the whole area of the mountains, even on the summits. Since then most of periglacial smooth slopes and nivation hollows have been stabilized being covered with kuroboku and/or peaty soil.

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