Seasonal snowpack dynamics and runoff in a cool temperate forest: lysimeter experiment in Niigata, Japan

• Published in: Hydrological processes Vol. 19; no. 20; pp. 4179 - 4200
• Main Authors: Whitaker, Andrew C., Sugiyama, Hironobu
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 30.12.2005; Wiley
• Subjects: albedo; Earth sciences; Earth, ocean, space; Exact sciences and technology; Hydrology; Hydrology. Hydrogeology; interception melt; Japan Sea region; lysimeter; rain on snow; snow hydrology; snowmelt; temperate forest; Niigata Japan; West Pacific; Far East; Honshu; Japan Sea; Japan; INW, Japan Sea; experimental studies; temperate forest; lysimeters; mass balance; springs; digital simulation; lysimeter; drainage basins; discharge; snowmelt; albedo; sublimation; base flow; models; rainfall; soil moisture; accumulation; runoff; Japan Sea region; rain on snow; water balance; climate; forests; meltwater; surface water; interception melt; Asia; snow; Pacific Ocean; snow hydrology; seasonal variations; streamflow
• ISSN: 0885-6087; 1099-1085
• DOI: 10.1002/hyp.6059

Seasonal snowpack dynamics are described through field measurements under contrasting canopy conditions for a mountainous catchment in the Japan Sea region. Microclimatic data, snow accumulation, albedo and lysimeter runoff are given through the complete winter season 2002–03 in (1) a mature cedar stand, (2) a larch stand, and (3) a regenerating cedar stand or opening. The accumulation and melt of seasonal snowpack strongly influences streamflow runoff during December to May, including winter baseflow, mid‐winter melt, rain on snow, and diurnal peaks driven by radiation melt in spring. Lysimeter runoff at all sites is characterized by constant ground melt of 0·8–1·0 mm day−1. Rapid response to mid‐winter melt or rainfall shows that the snowpack remains in a ripe or near‐ripe condition throughout the snow‐cover season. Hourly and daily lysimeter discharge was greatest during rain on snow (e.g. 7 mm h−1 and 53 mm day−1 on 17 December) with the majority of runoff due to rainfall passing through the snowpack as opposed to snowmelt. For both rain‐on‐snow and radiation melt events lysimeter discharge was generally greatest at the open site, although there were exceptions such as during interception melt events. During radiation melt instantaneous discharge was up to 4·0 times greater in the opening compared with the mature cedar, and 48 h discharge was up to 2·5 times greater. Perhaps characteristic of maritime climates, forest interception melt is shown to be important in addition to sublimation in reducing snow accumulation beneath dense canopies. While sublimation represents a loss from the catchment water balance, interception melt percolates through the snowpack and contributes to soil moisture during the winter season. Strong differences in microclimate and snowpack albedo persisted between cedar, larch and open sites, and it is suggested further work is needed to account for this in hydrological simulation models. Copyright © 2005 John Wiley & Sons, Ltd.