著者

山中 勤 田中 正 浅沼 順 濱田 洋平 YAMANAKA Tsutomu TANAKA Tadashi ASANUMA Jun HAMADA Yohei

出版者

Terrestrial Environment Research Center, the University of Tsukuba

雑誌

筑波大学陸域環境研究センター報告 = Bulletin of the Terrestrial Environment Research Center,the University of Tsukuba (ISSN:13463381)

巻号頁・発行日

vol.4, pp.51-59, 2003-10

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Water levels were measured for 34 wells in the Nasu Fan, Tochigi prefecture, in the end of October, 2002. Water quality of groundwater (34 samples), river water (6 samples) and spring water (3 samples) were also analyzed. Local relief of groundwater table is considerably low, and the typical value of its gradient is approximately 1/100. At an elevation between 220m and 250m, groundwater table approaches to the ground surface. Revival of interrupted stream of the Sabi River and the Houki River can recharge groundwater. These facts indicate that there is active interaction between groundwater and surface streams. Groundwater level fell over most part of the fan in recent 10 years. The maximum reduction of the groundwater level exceeds 3m. Increase in electric conductivity of groundwater was detected in some areas including urban areas.