Stormwater ponds are ubiquitous features of developed landscapes of the eastern United States. Their design specifically controls the pace of water runoff from impervious cover of surrounding watersheds. Ponds accumulate organic matter that typically decomposes anaerobically in bottom sediments, and thus may be significant sources of greenhouse gases to the atmosphere (e.g., carbon dioxide (CO₂), methane (CH₄)). We sampled fifteen stormwater retention ponds in southeastern Virginia (USA) during summer 2018 to determine the diffusive emission of greenhouse gases with respect to measured environmental parameters. The equivalent CO₂ (CO₂e) flux from ponds ranged from 8.3 to 80 mmol m^-2 h^-1, with CH₄ contributing 94%, CO₂ 6% and nitrous oxide less than 1% of the CO₂e flux, on average. From linear mixed-effects modelling, diffusive flux of CO₂ was inversely associated with pH. Maximum depth best explained diffusive flux of CH₄, with surface area of secondary importance, i.e. CH₄ flux was higher in smaller and more shallow ponds. With 300 stormwater ponds in the county where we conducted this study, we estimate that, during a 100-day warm season, these ponds emit 2.3 × 10⁹ ± 1.5 × 10⁹ SD g C as CO₂e. As small, human-constructed ponds are becoming common features of urbanizing landscapes globally, results from this study suggest that, collectively, small ponds can contribute substantially to climate forcing. Better pond designs that reduce sediment methanogenesis, however, can mitigate the hypothesized potential disservice of GHG emissions from unvegetated stormwater retention ponds.

雨水塘是美国东部发达景观的普遍特征。他们的设计专门控制了周围流域的不透水覆盖面的径流速度。池塘中积累的有机物通常会在底部沉积物中厌氧分解，因此可能是向大气排放温室气体的重要来源（例如，二氧化碳（CO ₂），甲烷（CH ₄））。我们在2018年夏季对美国弗吉尼亚州东南部的15个雨水蓄水池进行了采样，以确定相对于测得的环境参数而言的温室气体扩散排放量。池塘的等效CO ₂（CO ₂ e）通量范围为8.3至80 mmol m ^-2  h ^-1，平均而言，CH ₄贡献了94％，CO ₂ 6％和一氧化二氮少于CO ₂ e通量的1％。根据线性混合效应模型，CO _2的扩散通量与pH呈负相关。最大深度最好地解释了CH _4的扩散通量，具有次要的表面积，即CH ₄通量在较小和较浅的池塘中较高。在进行这项研究的县中，有300个雨水塘，我们估计在100天的温暖季节，这些雨水以CO ₂排放2.3×10 ⁹  ±1.5×10 ⁹ SD g Ce。随着人工建造的小型池塘在全球范围内日益成为城市化景观的共同特征，这项研究的结果表明，总体而言，小型池塘可对强迫气候做出重大贡献。但是，更好的池塘设计可以减少沉积物的甲烷生成，但可以减轻无植被雨水蓄积池假设的潜在温室气体排放。