We examine the influence of groundwater flow patterns and denitrification on nitrate migration in a regional recharge zone. It has been shown that nitrate contamination has a different behaviour in regions where groundwater is exploited (where deep percolation of nitrate takes place) than where natural gradients exist (with no deep aquifer zone contamination). Multicomponent chemical tracers and isotopic methods were used in the investigation. A contaminant plume was discovered in shallow parts of the aquifer which percolated into deeper parts of the flow system in those regions with a downwards gradient induced by groundwater withdrawal, where the influence of denitrification was limited. Local conditions leading to intense denitrification, i.e., local changes in geological conditions (low-permeability silt intercalations), were also documented. Therefore, vertical changes in groundwater chemistry should be examined to ensure groundwater resource management and protection, as these are extremely important in regional recharge zones with a downwards gradient.

我们研究了地下水流动模式和反硝化作用对区域补给区硝酸盐迁移的影响。已经表明，硝酸盐污染在地下水开采区（硝酸盐发生深度渗透）与存在自然梯度的地区（没有深层含水层污染）具有不同的行为。调查中使用了多组分化学示踪剂和同位素方法。在含水层的浅部发现了一种污染物羽流，该羽流渗入到地下水抽取引起的向下梯度区域的流动系统的较深部分，这些区域反硝化作用的影响有限。还记录了导致强烈反硝化的局部条件，即地质条件的局部变化（低渗透性淤泥夹层）。