ABSTRACT

The study assesses the extent of nitrate pollution in the Densu Basin, because of its predominance in agriculture and urbanized vicinities, by employing robust techniques to estimate both the natural background and human-induced concentrations. Statistical methods used are the pre-selection method, graphical approach (probability plot), non-parametric approach (kernel density estimation), and parametric approach (Gaussian mixture model). The study shows that the Gaussian mixture model is robust enough in determining the spectral distribution and clustering of the NO₃-N concentration in the basin. It estimated the natural background and human-induced concentration at 1.7 ± 1.3 and 9.8 ± 5.6 mg/L, respectively. The results show that the natural background concentration in the basin is more dominant and, hence, conducive for drinking. We found a 26% contribution from anthropogenic sources that had leaked into the natural groundwaters of the Basin. The data suggest multiple sources of NO₃-N concentration in the groundwater.

摘要

该研究通过采用可靠的技术来估计自然背景和人为引起的浓度，评估了 Densu 盆地的硝酸盐污染程度，因为它在农业和城市化附近地区占主导地位。使用的统计方法是预选方法、图形方法（概率图）、非参数方法（核密度估计）和参数方法（高斯混合模型）。研究表明，高斯混合模型在确定 NO _{3的光谱分布和聚类方面具有足够的鲁棒性。}-N 在盆地中的浓度。它估计自然背景和人为诱导的浓度分别为 1.7 ± 1.3 和 9.8 ± 5.6 mg/L。结果表明，流域内的自然本底浓度更为显着，因此有利于饮用。我们发现 26% 的贡献来自泄漏到盆地天然地下水中的人为来源。数据表明地下水中 NO ₃ -N 浓度的多个来源。