Abstract Three hydroelectric reservoirs (Kralkizi, Dicle and Batman) in the Tigris River basin (Turkey) were sampled monthly during one year in order to reveal spatial and seasonal changes in aqueous partial pressure of CO2 (pCO2) and to estimate diffusive fluxes of CO2 from the reservoirs’ surface water. pCO2 concentrations did not show significant spatial differences, while they showed significant seasonal variations. Temperature, precipitation and biological CO2 uptake through photosynthesis controlled pCO2 seasonality in the reservoirs, with maximal concentrations in the winter (ranging from 516.9 µatm in Kralkizi to 1299.2 µatm in Dicle) and minimal concentrations in the spring (ranging from 47.7 µatm in Batman to 140.7 µatm in Kralkizi). Most studies reported that reservoirs worldwide are net sources of CO2 to the atmosphere. However, the reservoirs in this study were sinks for atmospheric CO2 during the spring, summer and autumn seasons, while they were CO2 sources to the atmosphere during the winter. Air-water CO2 fluxes in Kralkizi, Dicle and Batman dam reservoirs were 2.39, 32.88 and 8.12 mmol/m2/day in the winter, respectively. On an annual basis, all three reservoirs acted as a sink for atmospheric CO2. These estimated CO2 fluxes were in the lower range for temperate reservoirs, despite the potential for winter conditions that shifted the reservoirs from sink to net source for atmospheric CO2.

中文翻译：

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土耳其东南部半干旱地区底格里斯河流域水电站的二氧化碳排放量

摘要 底格里斯河流域（土耳其）的三个水电站（Kralkizi、Dicle 和 Batman）在一年内每月采样，以揭示 CO2 水分压 (pCO2) 的空间和季节变化，并估计来自水库的地表水。pCO2 浓度没有显示出显着的空间差异，但它们显示出显着的季节性变化。通过光合作用进行的温度、降水和生物 CO2 吸收控制了水库中 pCO2 的季节性，冬季浓度最高（从 Kralkizi 的 516.9 µatm 到 Dicle 的 1299.2 µatm），春季最低浓度（从 Batman 的 47.7 µatm 到 140.7 µatm） µatm 在 Kralkizi）。大多数研究报告说，全世界的水库是大气中二氧化碳的净来源。然而，本研究中的水库在春季、夏季和秋季是大气 CO2 的汇，而在冬季则是大气 CO2 的来源。冬季 Kralkizi、Dicle 和 Batman 大坝水库的空气-水 CO2 通量分别为 2.39、32.88 和 8.12 mmol/m2/天。每年，所有三个水库都充当大气 CO2 的汇。这些估计的 CO2 通量在温带水库的较低范围内，尽管冬季条件可能会将水库从大气 CO2 的汇转移到净源。分别。每年，所有三个水库都充当大气 CO2 的汇。这些估计的 CO2 通量在温带水库的较低范围内，尽管冬季条件可能会将水库从大气 CO2 的汇转移到净源。分别。每年，所有三个水库都充当大气 CO2 的汇。这些估计的 CO2 通量在温带水库的较低范围内，尽管冬季条件可能会将水库从大气 CO2 的汇转移到净源。