Water flows in peatland margins is an under-researched topic. This study examines recharge from a peatland to an esker aquifer in an aapa mire complex of northern Finland. Our objective was to study how the aapa mire margin is hydrogeologically connected to the riverside aquifer and spatial and temporal variations in the recharge of peatland water to groundwater (GW). Following geophysical studies and monitoring of the saturated zone, a GW model (MODFLOW) was used in combination with stable isotopes to quantify GW flow volumes and directions. Peatland water recharge to the sandy aquifer indicated a strong connection at the peatland–aquifer boundary. Recharge volumes from peatland to esker were high and rather constant (873 m³ d⁻¹) and dominated esker recharge at the study site. The peat water recharging the esker boundary was rich in dissolved organic carbon (DOC). Stable isotope studies on water (δ¹⁸O, δ²H, and d-excess) from GW wells verified the recharge of DOC-rich water from peatlands to mineral soil esker. Biogeochemical analysis revealed changes from DOC to dissolved inorganic carbon in the flow pathway from peatland margin to the river Kitinen. This study highlights the importance of careful investigation of aapa mire margin areas and their potential role in regional GW recharge patterns.

泥炭地边缘的水流是一个尚未得到充分研究的话题。这项研究研究了芬兰北部aapa沼泽复合体中的泥炭地到esker含水层的补给。我们的目标是研究aapa泥潭边缘在水文地质学上如何与河岸含水层以及泥炭地水补给地下水（GW）的时空变化。在地球物理研究和对饱和带的监测之后，将GW模型（MODFLOW）与稳定同位素结合使用以量化GW的流量和方向。泥炭地向砂质含水层的补给表明泥炭地-含水层边界之间的联系很紧密。从泥炭地到埃斯凯的补给量很高，并且相当恒定（873 m ³ d ^-1），并在研究地点主导了esker补给。补充埃斯克边界的泥炭水富含溶解的有机碳（DOC）。水稳定同位素研究（δ ¹⁸ O，δ ² H，和d-过量）从GW井从泥炭到矿质土壤蛇形丘验证的富DOC-水补给。生物地球化学分析表明，在从泥炭地边缘到基蒂宁河的流动路径中，DOC从DOC变为溶解的无机碳。这项研究强调了仔细研究aapa泥沼边缘地区及其在区域GW补给模式中的潜在作用的重要性。