Geomorphological studies often require the accurate and efficient acquisition of topographic data. A set of elevation data for different periods is particularly important, because it permits the evaluation of landform change. To obtain such data in a form of the digital elevation model, photogrammetric techniques have been applied to aerial and terrestrial photographs. This approach has often been taken in North America and Europe to facilitate geomorphological research including the analysis of river channel shift, landslide movement, and gully erosion. In contrast, Japanese geomorphologists have only infrequently applied photogrammetric techniques. To facilitate such studies in Japan, this paper reviews photogrammetric applications in geomorphology with emphasis on four aspects : 1) historical development of photogrammetric techniques ; 2) overview of case studies in regions other than Japan especially North America and Europe ; 3) characteristics of relevant studies in Japan ; and, 4) errors in topographic measurements by photogrammetry.
The Sekidoh-Hohdatsu mountains, contacted with the Ohchi plains by NE-SW orientated lineal foothills, can be divided into five blocks by E-W orientated geological structures. The five blocks are Sakiyama-penninsula block, Nanao block, Kashima block, Shio block, and Mt. Hohdatsu block from north to south. E-W orientated geological structures are Sano-Iori fault, Korosa fault, Inoyama-Yabuta line, and Hohdatsusan fault from north to south. Each block and each geological structure among the blocks also can be found with many features on the face of the gravitational basement made out by a numerical analysis based on gravity prospecting. Another interesting piece of information from gravity data, for example, is that the Ohchi plains have a concave shape profile on the face of the gravitational basement only in the region from Korosa fault to Hohdatsusan fault. The result of an investigation on mutual movement among blocks, using geographical, geological, and gravitational features of blocks, shows that the formation of the SekidohHohdatsu mountains might have progressed due to an upheaval movement controlled by the block structure, and also continued in the Quaternary period. Putting blocks in the correct order of the latest time of an upheaval movement north of the Hohdatsusan fault, the oldest block is the Sakiyama-penninsula block or the Sio block. The next oldest is the Nanao block. And, the most recent one is the Kashima block. It probably moved in the Late Pleistcene age. For that reason, it is difficult to conclude that the fault that may exist beneath the boundary area between Skidoh-Hohdatsu mountains and Ohchi plains, have been simultaneously active.
The Paleozoic Radiolaria, a major zooplankton group with a siliceous skeleton, comprises 147 genera, 29 families, and 5 suborders. The compilation of 270 literatures on secular diversity change of Paleozoic radiolarians clarifies 7 distinct radiolarian extinction events : Event 1 at the Tremadoc/Arenig boundary (Early Ordovician), Event 2 at the Llandovery/ Wenlock boundary (Early Silurian), Event 3 at the Late Ludlow, Event 4 at the Early/Middle Devonian boundary, Event 5 at the Frasnian/Famennian (F/F) boundary, Event 6 at the Devonian/Carboniferous (D/C) boundary, and Event 7 at the Early/Late Carboniferous boundary. The Paleozoic radiolarians are divided into 3 major groups : a spherical-shell group composed of Spumellaria and Entactinaria ; a cylindrical to conical-shell group composed of Albaillellaria and Nassellaria; and, a flattened-shell group composed of Stauraxonaria. The spherical-shell group declined remarkably at Events 1, 2, 3, 4, and 5, while the cylindrical to conical-shell group declined at Events 6 and 7. The spherical-shell group dominated the Late Paleozoic epicontinental realm, while the cylindrical to conical-shell group dominated the pelagic realm. Events 1-5 represent diversity loss of radiolarians in the epicontinental habitat, while Events 6 and 7 represent diversity loss of pelagic inhabitants. Events 6 and 7 coincide with the timings of continental glaciation, suggesting that the decline of the pelagic radiolarians may have been related to global cooling. It is noteworthy that a significant extinction of radiolarians occurred at the F/F boundary (Event 5), although Radiolaria has previously been regarded to have flourished even across the boundary. Events 1 and 4 are the most significant radiolarian extinction events among 7 events, and occurred synchronously with faunal changes of other planktonic biota. Although terrestrial and benthic records suggest minor crises at these events; a global turnover is emphasized for marine planktonic biota.
Chemical weathering of silicate minerals in rocks controls the dissolved silica concentration of riverwater. This means that the dissolution rate of silicate minerals is an important factor for dissolved silica concentration. In addition to the dissolution rate, runoff (Δf) is also an important factor controlling riverwater chemistry. Therefore, the relationshipof the dissolved silica concentration, runoff, and dissolution rate of silicate mineral (feldspar) were theoretically derived on the basis of a dissolution kinetics-fluid flow coupling model. This theoretical consideration indicates that the parameter, φk (A/M), in which φ : porosity, h : thickness of reservoir of groundwater, k : dissolution rate constant, together with Δf, affects the dissolved silica concentration. If Δf is low compared to φ hk (AIM), the concentration (C) is equal to the equilibrium concentration. If Δf is high, C negatively correlates with Lf. This theoretical curve showing the relationship between the dissolved silica concentration and runoff is consistent with the dissolved silica concentration and runoff data of a major global riverwater.
High-resolution sedimentological analysis of core samples from the Tokushima Plain enable us to identify evidence for multiple faulting of the Median Tectonic Line active fault system (MTL) during the Holocene period. Continuous and close-interval analyses of lithology (0.5 cm-order) and magnetic susceptibility (2 cm-interval) were carried out on three core samples from the hanging wall and footwall sides of the Naruto-minami fault, which is part of the MTL. In addition, analyses of grain size (10 cm-interval) and composition of very fine sand fraction (20 cm-interval) were carried out on core samples obtained at both ends of the fault deformation zone. Based on these sedimentological analyses, we correlated 34 horizons across the bore holes and divided the strata into 8 sedimentary units. We also identified 6 intervals that are thicker at the footwall side of the fault. These intervals appear to be related to movements of the MTL and the age of these paleoseismic events are estimated on the basis of radiocarbon ages. At least 6 paleoseismic events are detected for the last 15000 years : 15151700 cal BP, 28003200 cal BP, 34004200 cal BP, 73007600 cal BP, 970010100cal BP, 1300015000 cal BP. The average dip slip rate of the Naruto-minami fault is estimated at 1.2 mm/year.
In this paper the author analyses agricultural land use changes in the urban shadow of the Sydney metropolitan region and clarifies their sustainability on a micro-scale using the example of Castlereagh area, Penrith City. Castlereagh area is situated around the western suburbs of Sydney city centre, and is characterised by competition between agricultural and urban land use. In this area, rural and agricultural land use has generally developed since the colonial period. Although definite changes from agricultural to urban land use are not apparent with the advancement of urbanization, some kinds of agricultural use have changed to others in terms of function and quality since the 1990s. This sustainability of agricultural land use changes based on land, climate, and historical conditions as a suitable region for agriculture, and accessibility to the urban market for agricultural products, and land use policy of city planning and land use zoning. In Castlereagh area dairy farming and sheep grazing have traditionally developed with advantageous land and climate conditions for grass production. In particular, suburban dairy farming was important for town milk production. Although there were a few trends of conversion from dairy farming to sheep grazing, because of a decreasing agricultural labour force, the framework of traditional pastoral farming still remained until the 1980s. Since the 1990s most aspects of pastoral farming have changed into horse raising, horticulture, and hobby farming with the enlargement of urban land use for residential and factory sites. Such farming has been most apparent among all kinds of land use in the 1990s. Under an environment of urban shadow, both horse raising and horticulture have developed due to their suitability for expanding urban land use and farmland subdivisions. Agricultural land use changes are supported by economic factors such as capital intensity and high profitability. On the other hand, hobby farming is less intensive and rather unprofitable, and is developed for the mental satisfaction of aged and the urban residents, rather than the advancement of urbanisation and land subdivision. Therefore, agricultural land use changes into hobby farming are supported by non-economic factors such as productive aging and mental satisfaction. On the whole, a series of agricultural land use changes are identified for their sustainability, and are supported by economic and non-economic factors. In particular, hobby farming plays an important role in holding back urban sprawl and maintaining agricultural land use.
The purpose of this study is to elucidate the formation process at a port space of local port. This kind of study is rare in geographical research, although ports have been greatly transformed in recent years. This study chiefly analyzes the issues of transportation mode and industrial structure in the port hinterland. Kushiro port, which is the largest port in eastern Hokkaido, is the selected study area. In this study, the following become clear. At the beginning of reclamation, the head of a bay or a river mouth that had the calm waters was used for a port. For example, Kushiro Port, which is situated at the mouth of the Kushiro River, began to operate as port in the Edo era, and developed by incorporating its river valley into the hinterland. At that time, port was a stage on the trading beach. Mother ships could not reach the coast directly, because there were no loading facilities such as quays and loading machines. Therefore, cargoes were transported between mother ship and beach by barge. A railway constructed from the port to the hinterland brought a large amount of cargo to the port. Port space was demanded in response. Then, instead of the past trading beach, a quay where barges were able to come alongside safely was constructed and the rail cargo line was connected to it. As the quay was constructed on the assumption of railway transportation, integration of railway and port was brought about. Hence, the town became separated from the port by the railway. In Kushiro, barge quays progressed along both sides of the Kushiro River, which had calm waters. This expanded the port space to the river area. After World War II, urgent reclamation and economic growth brought rapid development of industry, and exports increased. Transport networks, whose main transportation mode was rail, developed further. The port responded to the increasing cargoes by constructing a pier along the coast in front of the town. Mother ships could then come alongside the pier. As this pier was constructed on the assumption of mass railway transportation, a large site for railway transportation was prepared at and behind the pier. This separated the port from the town. On the other hand, most of the former quays were deprived of loading functions and gradually declined. In Kushiro Port, two new piers were constructed along the coast in front of the urban area, and most of the quays along the Kushiro River declined. Kushiro Port in this era had the following features. The ratio of rail transport facilities occupying the port space was large. Rail transport facilities separated the port from the urban area. The vast storage facilities for coal, which reflected the industry in hinterland, were located behind the loading facilities. Motorization, which started from about the mid- 1960's, brought the development of the road network and the decline of the railway network. Rapid economic growth changed the industrial structure in the hinterland. The development of motorization and changes in the industrial structure in the hinterland caused the port to respond by constructing a new port adjacent to the former port. This new port has the following characteristics. Large transportation spaces are prepared behind the piers for to truck transportation. Each pier is specialized for an industry in the hinterland. For example, each new pier of Kushiro Port specializes in oil industry, paper industry, and dairy farming. Port functions moved consecutively from the old port to the new port. With the construction of the new port, the port space of the old port was reorganized. Port space near CBD became the target of waterfront development in Kushiro. New commerce, business, culture, and sightseeing facilities were constructed there. The loading function of the old port is seen at both ends of the old port however, in the greater part of the port space, sheds and warehouses became obsolete.
Subevents of the 1946 Nankai earthquake (Mjma8.0) were distinguished from seismograms recorded on smoked papers with strong motion seismograms (T0=6s, amplification=2) and seismological data of Japan Meteorological Agency. Location and origin time of each subevent were roughly estimated from a hypocenter determination with phase readings of P and S waves for the subevent. Rupture of the Nankai earthquake started at a point southward about 50km off Cape Shionomisaki (first subevent). The rupture propagated in the NNW direction with a rupture velocity of 1.9 km/s and a second subevent that grew to class M8 started after about 16 sec from the initiation of the first subevent. Then the rupture propagated westward, and third subevent of M8 occurred around Tosa Bay, located about 200 km from the second event, about 53 sec after the initiation of the second event. Seismic waves were excited near Tosa Bay during the 1946 Nankai earthquake.
Analyzing landforms and sedimentary features, and the dominant factors affecting their formation, the lower Song Hong Delta is divided into natural levee and back swamp, delta, tidal flat, sand ridge complex. The dominant process in the coastal area is deposition and the shoreline has moved seaward at various rates in modern times, however, coastal erosion has recently been occurring in the south of the river mouth. The erosion rate has been 32.3 m/y at Hai Trieu for the last 20 years. The most intensive accretion occurred at Kim Son-Nga Son, where the average rate of accretion has been 60-80 m/y for the last 50 years.