Characteristics of the water cycle in the discontinuous permafrost region in interior Alaska

• Main Authors: イシカワ ノブヨシ, サトウ ノリフミ, カワウチ クニオ, ヨシカワ ケンジ /, Nobuyoshi Ishikawa, Norifumi Sato, Kunio Kawauchi, Kenji Yoshikawa, Larry D. Hinzman
• Format: Report
• Language: English
• Published: Scientific Paper 2001
• Subjects: Caribou-Poker Creeks Research Watershed; permafrost; Polar meteorology and glaciology; Alaska
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2932; http://id.nii.ac.jp/1291/00002932/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2932&item_no=1&attribute_id=18&file_no=1

In order to better understand the water cycle in the discontinuous permafrost area, field observations of soil moisture content, groundwater table, discharge and evaporation have been carried out in the Caribou-Poker Creeks Research Watershed since 1997. This investigation aims to characterize the soil moisture and ground water dynamics of interior Alaska. Soil moisture content depends on topographic factors, increasing toward the bottom of a slope. In the flood plain, soil moisture is higher in depressions than on mounds. The depth of the active layer is less than 1m at the end of summer and unfrozen soil exists below the permafrost, as determined through geophysical exploration and drilling. The groundwater table reaches a maximum height in early October and decreases monotonically to reach a minimum in early April, then starts to increase after snowmelt. The ground water of a shallow well and soil moisture near the ground surface show variations, as influenced by precipitation and evaporation; however, a deeper well on the upper slope does not respond similarly. Evaporation occurs over the whole watershed during summer; however, directly over a stream condensation dominates because of low water temperature due to the permafrost underneath.