Title: Comparison of isotope analysis and tank model calculation method to determine the snowmelt water ratio in river water
Authors: Shigeki Harada; Taisuke Hashimoto; Taisuke Sato
Addresses: Department of Environmental Sciences, School of Food, Agricultural and Environmental Sciences, Miyagi University, 2-2-1 Hatadate, Taihaku-ku, Sendai 982-0215, Japan ' Department of Environmental Sciences, School of Food, Agricultural and Environmental Sciences, Miyagi University, 2-2-1 Hatadate, Taihaku-ku, Sendai 982-0215, Japan ' Department of Environmental Sciences, School of Food, Agricultural and Environmental Sciences, Miyagi University, 2-2-1 Hatadate, Taihaku-ku, Sendai 982-0215, Japan
Abstract: Isotope analysis of river water can be used to evaluate the contribution of snowmelt water in rivers because snow (precipitation) has relatively higher δ18O-NO3. Quantitative determination of snowmelt water input is needed for catchment environmental planning, agricultural planning and water resources planning in heavy snow regions, such as Miyagi Prefecture in Tohoku, Japan. We compared the measured δ18O-NO3 values in the Okura River (Sendai, Miyagi Prefecture) in the snowmelt seasons of 2013 and 2014 with the snowmelt water ratio calculated by the tank model for the years 1985 to 1989 and reported in Kato and Kurashima (1998). Although the seasonal periods of δ18O-NO3 measurements were not identical with the earlier period, with consideration of the meteorological conditions, variation in δ18O-NO3 was well explained by the contribution of snowmelt water to the river determined by the tank model. Thus, measured δ18O-NO3 could be used for catchment environmental planning in the region. This case study demonstrates the potential use of δ18O-NO3 values for determining the snowmelt water ratio in other rivers.
Keywords: snowmelt water ratio; stable isotope ratio; tank models; heavy snow areas; meteorological conditions; Okura River; Japan; river water; nitrate; oxygen-18; delta-O-18; catchment environmental planning; agricultural planning; water resources planning.
DOI: 10.1504/IJHST.2017.080955
International Journal of Hydrology Science and Technology, 2017 Vol.7 No.1, pp.1 - 11
Received: 14 May 2015
Accepted: 29 Dec 2015
Published online: 13 Dec 2016 *