Proceedings of the General Meeting of the Association of Japanese Geographers

Characteristics of acid sulfate soil and landform evolutions were studied in the coastal plain around Nakhon Si Thammarat, southern Thailand. The coastal plain is characterized as the low and flat coastal plain with several rows of beach ridges. Broad swampy area develops behind the distinct row of beach ridge on which the urban area of Nakhon Si Thammarat is located. Acid sulfate soil mostly develops in the swampy area behind the distinct beach ridge. Surface geology of the region were studied at about 50 sites with a hand auger. Six soil samples in the region were collected and measured for PH. The strong acid sulfate soil was measured in the horizons of peat layer which develops widely behind the long and distinct beach ridge. No acid sulfate soil can be seen in the outer area of the beach ridge where the land was extended after the middle Holocene transgression. From the results, it is clarified that acid sulfate soil occupies in the distinct area as bog which is enclosed with old beach ridges. The bog was former mangrove swamp in the period of middle Holocene, and sulfidic material accumulated in the time. After the culmination of the middle Holocene transgression, the younger beach ridge and coastal plain developped towards the east. The vegetation of the inner region changed to the secondary forest (such as salt grass and Melaleuca leucadendron) under reducing of salinity, and the sediment of secondary forest deposited on the sulfidic material of the mangrove peat. Consequently, environment of area change again by fresh water sediment deposited on the surface as thin topsoil.

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Holocene sea-level studies in the southern North Sea region of continental Europe situated in the subsiding area by glacio-isostasy were reviewed and the possibility of sea-level fluctuations was discussed. Most sea-level curves in this region were depicted indirectly through the groundwater-level curves reconstructed using radiocarbon data obtained from the base of basal peat underlain by Pleistocene or coastal dune deposits to eliminate the influence of compaction because most Holocene sediments consist of peat or clay. To detect sea-level fluctuations using this method, it is required to collect as many samples as possible with clear relation to groundwater level on a slope of basement considering various local factors such as river gradient effect, flood depression effect, opening-closing effect of coastal barrier, and micro-topographical effect of basement slope. Even if all these conditions were overcome, it is difficult to find out evidence of temporal sea-level fall because it induces the decomposition of peat surface, and a new layer of peat accumulates on the former peat layer with the following sea-level rise. As a result, the apparent decrease in the rate of sea-level rise or stagnation must be found out. Only two former studies, one by Van de Plassche (1982) for the western Netherlands and the other by Behre (2003) for northwest Germany, aimed to find out sea-level fluctuations in this region. Van de Plassche (1982) found out changes in the rate of groundwater-level rise several times between 7000 and 2800 cal BP using the data obtained from the base of basal peat and discussed the relationship with sea-level fluctuations. Behre (2003) depicted a sea-level curve with several times of sea-level fall during the last 9700 cal BP. However, the reliability of this curve for amplitude and level was not always high, though the timing can be discussed, because some samples for sea-level index points involved the influence of compaction, and the changes in sea level were inferred from the formative periods of peat layers and occupation layers. Sea-level fall or stagnation between 5200 and 4500 cal BP and acceleration of sea-level rise between 4500 and 4100 cal BP were found in both curves. Between 3300 and 2900 cal BP, abrupt sea-level fall was inferred in northwest Germany, whereas the sea-level in the western Netherlands was almost in stagnation. The abrupt sea-level fall depicted in the sea-level curve of northwest Germany is likely to reflect the effect of compaction because the desalination of saltmarshes and seaward expansion of peatlands were not recognized for this period. The temporal emergence of saltmarshes between 2350 and 1900 cal BP suggests the sea-level fall and the following sea-level rise. These trends almost synchronize with the trends in the Asia-Pacific region except for the relative rapid sea-level rise prior to decelerating around 5200 cal BP.

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The water quality survey was carried out in Parasi area in Nawalparasi County which locates in Terai lowland in Nepal, during 2 days, March 1 and March 2, 2008. Under this investigation, thirty hamlets which are scattered around the rural region of about 6 km to east and west and about 10 km to north and south were considered as our study area. At each farming village, the water quality of one selected well was investigated.

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In this report, we discuss about the distribution characteristic of accommodations and the differentiation of tourism function in Kyongju City, Korea.
There are four accumulation area of accommodations in Kyongju. The each area has different spatial characteristic and lured different type of tourist. We found that the tourism function has differentiated according to the characteristic of accommodations and localities.

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