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Masami Izuho Yuichi Nakazawa Fumito Akai Tsutomu Soda Hirotaka Oda 《Geoarchaeology》2009,24(4):492-517
In order to better understand modern human behavioral variability in Hokkaido, Japan, we consider the geoarchaeology of the Kamihoronai‐Moi site in terms of its geochronology, stratigraphy, depositional environments, and post‐depositional disturbances. A Paleolithic component is stratigraphically situated between the Eniwa‐a (15,000–17,000 14C yr B.P.) and the Tarumae‐d (8000–9000 14C yr B.P.) tephras. Moreover, six AMS 14C ages on charcoal from a Pleistocene‐aged hearth feature are between 14,400 and 14,800 14C yr B.P. Quantitative examinations of patterns in artifact distributions show a low degree of vertical and horizontal displacement of chipped‐stone artifacts, suggesting that post‐depositional movement of the cultural material was insufficient to disrupt the original pattern of artifact distribution. © 2009 Wiley Periodicals, Inc. 相似文献
73.
Tornado shelter-seeking behavior and tornado shelter options among mobile home residents in the United States 总被引:2,自引:2,他引:0
Residents of 401 mobile homes in Georgia, Mississippi, Illinois, and Oklahoma were surveyed after they heard a tornado warning.
Most residents (69%) did not seek shelter during the warning. Half of those who sought shelter went to the frame house of
a friend, neighbor, or relative, and 25% of those sought shelter in a basement or underground shelter. Some of the places
where residents sought shelter were of dubious quality, such as their own mobile home, another mobile home, or in an out-building.
Twenty-one percent of mobile home residents believed that they had a basement or underground shelter available as shelter
during a tornado warning, and about half of those said they would drive to the shelter. Residents said they would drive if
the shelter was more than 200 m away. Fifteen percent actually had a basement or underground shelter suitable as shelter within
200 m of their mobile home, but only 43% of the residents would use those shelters. The most common reason cited for not using
the shelters was that they did not know the people who lived there. Likewise, a frame house or other sturdy building was within
200 m of 58% of the mobile homes, but only 35% of the residents stated they would use those houses for shelter. Thirty-one
percent of mobile home residents had a ditch that was at least 0.5 m deep within 200 m of the mobile home. However, 44% of
these ditches had utility lines overhead, 23% had water in them, and 20% had trees overhead. The limited tornado shelter options
among mobile home residents in the United States needs to be incorporated into safety instructions so that residents without
nearby shelter are allowed to drive to safer shelter. 相似文献
74.
Death tolls from tornadoes in Bangladesh are the highest in the world due to lack of storm warnings, poor communication, weak
housing, and lack of shelters from strong winds in tornadoes and nor’westers. Based on surveys of housing types and designs
in the Tangail district, a household tornado shelter is proposed to be placed in the elevated storage platform that is common
in houses. The shelter is 2 m tall, 1.2 m wide, and 2–4 m long (4.8–9.6 m3 in volume) with the floor of the shelter placed one meter below the floor of the house. Walls are 7–10 cm thick and made
of concrete or an earthen wall stabilized with cement or strengthened with bamboo or bricks. A survey of 200 residents of
the region found nearly universal acceptance for the shelter design, and residents were eager for installation of the household
shelters. The shelter cost is 2,500–10,000 taka (US50 to50 to 200) depending on local material and labor costs but residents
were willing to pay an average of only 1,071 taka (US$21) toward the cost of the shelter. Families with greater income and
land holdings and families in villages with recent tornado experience were willing to spend more for a shelter. A pilot project
to install household tornado shelters in selected villages and monitor their use, along with continued efforts to issue storm
warnings, communicate the warnings, and improve education about storm hazards, will prevent injuries and save lives in Bangladesh
and reduce the descent into poverty that results from losses in severe local storms. 相似文献
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The role of bedrock groundwater in rainfall–runoff processes is poorly understood. Hydrometric, tracer and subsurface water potential observations were conducted to study the role of bedrock groundwater and subsurface flow in the rainfall–runoff process in a small headwater catchment in Shiranui, Kumamoto prefecture, south‐west Japan. The catchment bedrock consists of a strongly weathered, fractured andesite layer and a relatively fresh continuous layer. Major chemical constituents and stable isotopic ratios of δ18O and δD were analysed for spring water, rainwater, soil water and bedrock groundwater. Temporal and spatial variation in SiO2 showed that stream flow under the base flow condition was maintained by bedrock groundwater. Time series of three components of the rainstorm hydrograph (rainwater, soil water and bedrock groundwater) separated by end member mixing analysis showed that each component fluctuated during rainstorm, and their patterns and magnitudes differed between events. During a typical mid‐magnitude storm event, a delayed secondary runoff peak with 1·0 l s−1 was caused by increase in the bedrock groundwater component, whereas during a large rainstorm event the bedrock groundwater component increased to ≈ 2·5 l s−1. This research shows that the contribution of bedrock groundwater and soil water depends strongly on the location of the groundwater table, i.e. whether or not it rises above the soil–bedrock interface. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Shigeru Mizugaki Yuichi Onda Taijiro Fukuyama Satoko Koga Hiroki Asai Shinya Hiramatsu 《水文研究》2008,22(23):4519-4531
To analyse suspended sediment sources in unmanaged Japanese cypress plantation watersheds, field measurements and fingerprinting of the suspended sediment was conducted in the Shimanto River basin in southern Japan. For sediment fingerprinting, 137Cs and 210Pbex were detected by means of gamma‐ray spectrometry in the surface soil of the forest floor, stream bank and truck trail and mobilized sediment by interrill erosion. The 137Cs and 210Pbex activities associated with the forest floor materials were considerably higher than those of the stream bank and truck trail. The 137Cs and 210Pbex activities associated with the suspended sediment were found to vary with the sampling period. Evidently, the suspended sediment can comprise materials generated from the forest floor by interrill erosion and those from the truck trail and/or stream bank. The multivariate sediment‐mixing model using 137Cs and 210Pbex showed that the contribution of the forest floor varied periodically, ranging from 23–56% in the Hinoki 156 subwatershed and from 18–85% in the Hinoki 155 subwatershed. The difference in the average contribution of the forest floor between Hinoki 156 (46%) and Hinoki 155 (69%) may relate to the presence of truck trail networks in the watershed. The truck trail network can play roles of sediment source and pathway for sediment from forest floor to stream channel due to the concentrated overland flow on the truck trail during heavy rainfall events. These results indicate that the forest floor should be recognized as a major source of suspended sediment in unmanaged Japanese cypress plantation watersheds. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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