ABSTRACT Stable isotopes in precipitation and spring water were observed in a low mountain region, because seasonal variability in isotope altitude and amount effects based on their simultaneous observations in low latitude area have not been studied so much. Seasonal variability in spatial averages of monthly δ18O and d-excess in precipitation ranged from −11.96 to −5.16 ‰ and from 8.0 to 24.2 ‰, respectively, while those in spring water ranged from −7.64 to −7.18 ‰ and from 11.0 to 13.6 ‰. The seasonal variability in spatial average of monthly δ18O in precipitation was much wider than in spring water. Monthly isotopic composition in spring water was mostly plotted along the local meteoric water lines for precipitation in warm months, suggesting that precipitation in warm months is the main source of spring water. Annual isotope altitude effects in precipitation (−0.12 ‰/100 m) and spring water (−0.13 ‰/100 m) were almost the same, and monthly isotope amount effects for cold months (−7.9 to −0.9 ‰/100 mm) were relatively higher than those for the warm months (−12.0 to −9.6 ‰/100 mm). The isotope amount effect at each sampling sites appeared using only the data in the warm months without extreme weather.

中文翻译：

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日本西南部熊本金浦山周围降水和泉水中稳定同位素的季节性变化

摘要 在低纬度地区观测到降水和泉水中的稳定同位素，因为在低纬度地区同时观测到的同位素海拔高度和数量效应的季节性变化还没有得到太多研究。月δ18O和降水d-excess空间平均值的季节性变化分别为-11.96～-5.16‰和8.0～24.2‰，而泉水的季节变化范围为-7.64～-7.18‰和11.0～13.6‰ . 降水中月δ18O空间平均值的季节性变化比泉水大得多。泉水中的月同位素组成主要沿当地大气水线绘制，以进行暖月降水，表明暖月降水是泉水的主要来源。降水 (-0.12 ‰/100 m) 和泉水 (-0.13 ‰/100 m) 的年同位素海拔效应几乎相同，寒冷月份 (-7.9 至 -0.9 ‰/100 mm) 的月同位素量效应为相对高于暖月 (-12.0 至 -9.6 ‰/100 mm)。每个采样点的同位素量效应仅使用没有极端天气的温暖月份的数据出现。