Abstract Stable isotopes have been used to quantify lake and wetland pond water loss to evaporation by applying the modified Craig and Gordon (1965) model. This model and its derivatives employ simplifying assumptions that ignore the additions of precipitation and infiltration outputs and assume evaporation is the only loss term over the prediction period. Here we develop a coupled water and isotope mass-balance model to account for precipitation additions. Our model uses physical and isotopic observations to quantify pond evaporation and infiltration losses over the ice-free period. We tested and applied the model to four wetland ponds at the St Denis National Wildlife Research Area, Saskatchewan Canada, where we have long-term datasets. Modeled infiltration rates from the ponds ranged between 0.99 and 9.2 mm/d and open water evaporation rates ranged between 0.88 and 2.8 mm/d. Both were consistent with independent estimates. Infiltration amounts were highest in the ephemeral ponds (that dry out within days or weeks of the spring melt period). In these ponds, infiltration exceeded evaporation. In permanent ponds, that is ponds that do not dry out; evaporation exceeded infiltration. Evaporation amounts were most substantial for permanent ponds that were not sheltered by topography or riparian vegetation. Overall, our coupled water and isotope mass-balance model combined with physical and isotope observations was able to quantify the spatially and temporally variable evaporation and infiltration fluxes within and between ponds.

中文翻译：

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量化湿地水平衡：一种新的基于同位素的方法，包括降水和渗透

摘要 稳定同位素已被用于量化湖泊和湿地池塘蒸发损失的水分，通过应用修改后的 Craig 和 Gordon (1965) 模型。该模型及其衍生模型采用了简化假设，忽略了降水和入渗输出的增加，并假设蒸发是预测期内唯一的损失项。在这里，我们开发了一个耦合的水和同位素质量平衡模型来解释降水的增加。我们的模型使用物理和同位素观测来量化无冰期间池塘蒸发和渗透损失。我们在加拿大萨斯喀彻温省圣丹尼斯国家野生动物研究区的四个湿地池塘中测试并应用了该模型，我们在那里拥有长期数据集。模拟的池塘渗透率介于 0.99 和 9 之间。2 mm/d 和开放水蒸发率介于 0.88 和 2.8 mm/d 之间。两者均与独立估计一致。临时池塘（在春季融化期的数天或数周内变干）中的入渗量最高。在这些池塘中，渗透超过蒸发。在永久性池塘中，即不会干涸的池塘；蒸发超过渗透。对于不受地形或河岸植被遮蔽的永久性池塘，蒸发量最大。总体而言，我们的耦合水和同位素质量平衡模型与物理和同位素观测相结合，能够量化池塘内部和池塘之间的空间和时间可变蒸发和渗透通量。临时池塘（在春季融化期的数天或数周内变干）中的入渗量最高。在这些池塘中，渗透超过蒸发。在永久性池塘中，即不会干涸的池塘；蒸发超过渗透。对于不受地形或河岸植被遮蔽的永久性池塘，蒸发量最大。总体而言，我们的耦合水和同位素质量平衡模型与物理和同位素观测相结合，能够量化池塘内部和池塘之间的空间和时间可变蒸发和渗透通量。临时池塘（在春季融化期的数天或数周内变干）中的入渗量最高。在这些池塘中，渗透超过蒸发。在永久性池塘中，即不会干涸的池塘；蒸发超过渗透。对于不受地形或河岸植被遮蔽的永久性池塘，蒸发量最大。总体而言，我们的耦合水和同位素质量平衡模型与物理和同位素观测相结合，能够量化池塘内部和池塘之间的空间和时间可变蒸发和渗透通量。对于不受地形或河岸植被遮蔽的永久性池塘，蒸发量最大。总体而言，我们的耦合水和同位素质量平衡模型与物理和同位素观测相结合，能够量化池塘内部和池塘之间的空间和时间可变蒸发和渗透通量。对于不受地形或河岸植被遮蔽的永久性池塘，蒸发量最大。总体而言，我们的耦合水和同位素质量平衡模型与物理和同位素观测相结合，能够量化池塘内部和池塘之间的空间和时间可变蒸发和渗透通量。