Proceedings of the General Meeting of the Association of Japanese Geographers

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The Lower Terrace and this formation are distributed on the fringe of the southern part of Nara Basin, Japan. I restore this accumulation initial surface from erosional features. Geological boundaries and gentle slopes seen iin so-called Yamato-Sanzan, three small mountains stated below, consisting of the igneous rock touched off this theme. I show vertical section views of Yamato-Sanzan whom I took along ridges to the chart below. Here a little less than 120 m above sea level can find Yamato-Sanzan common level to show it in broken line. In the neighborhood of this level, are recognized borders of intruded rocks and the granite on Unebiyama and of the gabbro and granite on Amanokaguyama, and gentle slopes of the rhyolite at the Miminashiyama. The erosion of the granite by weathering slowed down in this level, I read it. In other words these bodies lower than this level had been underearth. The current local erosion reference datum ranges 60 to 80 m above sea level as Yamato-Sanzan are located on gentle slopes. I will assume a higher stable basal level of erosion approximately 40 m from the present. In addition, decomposition of the granite excels in the vicinity of the earth surface where water movement is active. Leaching of potassium and sodium constituting the mineral of granite are to the zone of saturation top surface of the subsoil water wholly. The groundwater table links local basal level of erosion, and this enlarges headwards as headward erosion proceeds. The above mentioned higher basal level is corresponding to the Lower Terrace in the Ryumon Mountains to the south of Yamato-Sanzan and in the Kongo Mountains to the West. The left Lower Terrace considerably deteriorates now, but their pieces of the accumulation initial surface can be recognized. The alluvium of Nara Basin is extremely thin, and, according to the excavation data, and it is thought that the current basin is a dissected topography of the Lower Terrace.

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I researched the distribution of ceramic products that have been produced in the Iwami region since the late 19th century. I found that there are big jars or foof tiles made in the modern Iwami region coastal areas of the Japan Sea from Hokkaido to Honshu, and even in Sakhalin, Russia and Ulleungdo, South Korea. These ceramic products have some characteristic that is advantageous to the marine transportation. I can suggest that the distribution of ceramic products made in Iwami region is evidence that they were actively transported by ship around the coast of the Japan Sea in modern ages

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Accident of Fukushima-daiichi Nuclear Plant brought a loss of daily life in Abukuma Mountains. Dose rate distribution was mapped to understand the heterogeneous distribution of radioactive materials by using gamma ray spectrometer with GPS. The distribution was strongly influenced by the topography. The catchment on the Pacific side held most of the radioactive materials delivered from the nuclear plant located on the cost. The distribution pattern implied the dynamic behavior of radioactive plume at the fallout. The distribution in small watershed scale showed complicated but somewhat systematic distribution patterns correspond to topography, vegetation, and land use.

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Fukushima Prefecture experienced the multiple consequences of an earthquake after the March 11, 2011. We explore the impacts of these complex disasters with particular attention to the changed accessibility space among traditional regional divisions in Fukushima. First, we collected extensive data before and after the disasters. Second, we calculated the shortest travel times between 100 major towns and villages, comparing for both public and private transportation, based on GIS tools. Third, we applied Q-analysis to an OD matrix.It is presented that the huge disaster, especially after causing the devastating nuclear plant accident, divided the Hama-dori region into three parts.

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