Mestizo subsistence strategies in a floodplain community of the Peruvian Amazon are examined within a cultural ecological context. The riparian economy, derived from aboriginal techniques of resource utilization, consists of a systematic use of diverse biotopes that have been fashioned by the lateral and vertical dynamics of the river. The model of horizontal zonation of agriculture proposed by DENEVAN is adopted to explain the subsistence strategies of riparian mestizos. The bulk of the inhabitants' food and fiber needs is met through farming. Two farming systems, i.e., polycultural shifting cultivation and multi-variety permanent field cropping, are practiced by the residents. The former is carried out on the flood-free levee tops, while the latter occurs on terrain subject to annual inundation. Aside from farming, collecting, fishing, and hunting provide important supplementary sources of food and marketable goods. The traditional livelihood techniques have shown to be adaptable to commercial economy. As such, they may be of potential value in the development of the Amazon. Sustained-yield agriculture, and thus surplus food production is possible on the bottomland soils where plant nutrients are cyclically replenished by the floodwater. Agriculture based on multiple biotope use favors family farming; therefore, it offers the possibilities for accomodating a large number of inhabitants, especially from the densely populated regions with marginal agricultural possibilities. The floodplain environments appear to be more resilient under intensive and continuous use than the interfluvial areas where major ecological disruptions have resulted from large scale agricultural development attempts.
This paper investigates the residential structure of Tokyo, the largest city in Japan, in the 1910s middle period of Taisho by applying factorial ecological method. The principal factor method is applied to the original data matrix of 1920, which contains 816 districts in columns and 19 variables in rows. Six common factors whose eigen-values exceed 1.0 are obtained. The first factor is interpreted as the family status and the second factor as the public officials and liberal workers. It becomes clear that the fundamental residential structure of Tokyo in this period is composed of five residential groups; the large household of commercial worker, the unmarried persons who work in large stores, the medium-size household of manufacturing workers in the prime of life consisting of married couple and their children, various manufacturing workers and public officials and liberal workers. Consequently, it is clear that the residential structure of Tokyo in the middle period of Taisho cannot be explained by the simple division which divides Tokyo into eastern and western areas as considered in previous studies, but is at the stage of the residential structure of the industrializing city.
In order to clarify the late Holocene crustal deformations in the coastal area of southern Kanto, central Japan, the distribution, formative ages and height of Holocene marine terraces in the southern part of the Bose Peninsula, Miura Peninsula and Oiso-Kozu area were investigated. Distinct Holocene marine terraces can be divided into four levels (the Numa I-IV) in the southern part of the Boso Peninsula, three levels (the Nobi I-III) in the Miura Peninsula, and three levels (the Nakamura-hara, Maekawa and Oshikiri) in the Oiso-Kozu area. The ages of the Holocene marine terraces in the Miura Peninsula (the Nobi I-III) which had not been well known previously proved to be around 6, 000 y. B. P., 4, 600 y. B. P. and 3, 100 y. B. P. in descending order and they are considered to be correlative to the Numa I-III terraces. However, the fact that the terrace correlative to the Numa IV was not found in the Miura Peninsula and Oiso-Kozu area suggests that the emergence of the Holocene marine terraces did not always occur simultaneously throughout southern Kanto. The height distribution of the highest Holocene marine terrace surface (the Numa I, Nobi I and Nakamura-hara terrace surfaces), which were formed at the maximum rise of the Holocene transgression (ca. 6, 000 y. B. P.), shows warpings of WNW-ESE axes superposing upon the landward tilting. The height distribution cannot be explained by only coseismic uplift of 1703 and 1923 types. Holocene terrace surfaces are displaced by active faults in the Miura Peninsula and the Kozu-Matsuda fault. This displacement indicates that these faults have been active even in the late Holocene. The average uplift rates estimated from the height of the Holocene shorelines are larger than those estimated from the height of Pleistocene shorelines, therefore, it can be concluded that the crustal deformation in the Holocene is more active than that in the late Pleistocene.
Deterioration of groundwater environment is caused not only by the development of groundwater resources but also by the change of landform, the construction of buildings, etc. For instance, linear excavations for constructing roads or railways induce such phenomena as the lowering of groundwater level, water pollution and drying-up of wells. The purpose of this study is to estimate the fluctuations of groundwater level numerically which will be caused by linear excavations for road building using simulation models by way of an example at Kashiwa zone of Joban Motorway construction work. The numerical estimation is made on the basis of the data from a preliminary survey in February 1975 and several main surveys from April 1975 to March 1976. A two-dimensional horizontal model is used to simulate the flow of unconfined groundwater and a two-dimensional vertical model is also used to verify the results of computations with the horizontal model. The simulation domain is a belt zone with the length of 3.5 km and the width of 1.0 km along a part of the projected line for the road and three boundary conditions are set up: initial condition, dewatering condition and cut-off condition. In the first stage of calculation, the parameters of permeability, effective porosity, infiltration rate of precipitation and infiltration to confined groundwater are decided. The influence of the linear excavation is estimated in the second stage of calculation.
Factors affecting a large amount of forest evapotranspiration are studied through the observation of energy and water balances of a pine forest during a summer season. Latent heat flux was obtained with an eddy correlation/energy balance method. Canopy wetness was traced by using wetness indicators installed in the forest canopy. Interception of the forest canopy was obtained from the measurements of gross rainfall, throughf all, and stemflow. Evapotranspiration data of pasture field adjacent to the forest was also used as a reference. Through the analysis of these results, following conclusions were obtained: 1) Evapotranspiration rate of a wet canopy is some 30% faster than that of a dry canopy, so that canopy wetness proves to be an important factor on the determination of evapotranspiration in short time scale. 2) For the daily evapotrans-piration, canopy wetness is not an important factor, since canopy is rarely kept wet all day long in many cases. 3) Daily evapotranspiration of a forest is 35% larger than that of a pasture on an average and the differences in the amount of evapotranspiration are fundamentally due to the differences of available energy between them.
Tokyo is one of the largest cities in the world and has a population of 20 million within its metropolitan area. A short history of air quality in Tokyo and its surroundings is summarized in this paper. Urbanization and industrialization have induced a drastic change in air quality and urban climate in Tokyo during the past forty years. Heat island in the urban area is thought to be a good symbol of man-made climate. In accordance, the change of temperature distribution for every five years and also how temperature distribution is affected by air is mentioned.