Department of Leisure and Recreation Management, Kainan University, Taoyuan City, 338, Taiwan.
Environ Sci Pollut Res Int. 2023 Jul;30(33):81113-81130. doi: 10.1007/s11356-023-28208-2. Epub 2023 Jun 14.
Groundwater nitrate-nitrogen contamination typically involves several natural and anthropogenic factors, including those related to hydrology, hydrogeology, topography, and land use (LU). DRASTIC-LU-based aquifer contamination vulnerability could be used to characterize the pollution potentials of groundwater nitrate-nitrogen and to determine groundwater protection zones. This study used regression kriging (RK) with environmental auxiliary information on DRASTIC-LU-based aquifer contamination vulnerability to investigate groundwater nitrate-nitrogen pollution in the Pingtung Plain of Taiwan. First, the relationship between groundwater nitrate-nitrogen pollution and assessments of aquifer contamination vulnerability was determined using stepwise multivariate linear regression (MLR). Subsequently, the residuals between the nitrate-nitrogen observations and MLR predictions were estimated by kriging techniques. Finally, the groundwater nitrate-nitrogen distributions were spatially analyzed using RK, ordinary kriging (OK), and MLR. The findings indicated that the land used for orchards and the medium- and coarse-sand fractions of vadose zones were associated with groundwater nitrate-nitrogen concentrations. The fertilizer used for orchards was identified as the primary source of groundwater nitrate-nitrogen pollution. The RK estimates could be used to analyze the characteristics of the pollution source for land used for orchards and exhibited high spatial variability and accuracy after residual correction. Moreover, RK had an excellent estimate ability for extreme data compared to MLR and OK. Correctly determining groundwater nitrate-nitrogen distributions using RK was useful for administering environmental resources and preventing public health hazards.
地下水硝酸盐氮污染通常涉及多种自然和人为因素，包括与水文、水文地质、地形和土地利用（LU）有关的因素。基于 DRASTIC-LU 的含水层污染脆弱性可以用来描述地下水硝酸盐氮的污染潜力，并确定地下水保护区。本研究使用回归克里金（RK）方法，结合基于 DRASTIC-LU 的含水层污染脆弱性的环境辅助信息，研究了台湾屏东平原地下水硝酸盐氮污染。首先，通过逐步多元线性回归（MLR）确定了地下水硝酸盐氮污染与含水层污染脆弱性评估之间的关系。然后，通过克里金技术估计硝酸盐氮观测值与 MLR 预测值之间的残差。最后，使用 RK、普通克里金（OK）和 MLR 对地下水硝酸盐氮分布进行空间分析。研究结果表明，果园用地和包气带中中砂和粗砂部分与地下水硝酸盐氮浓度有关。果园使用的肥料被确定为地下水硝酸盐氮污染的主要来源。果园用地的 RK 估计值可用于分析果园用地污染源的特征，并在残差校正后表现出较高的空间变异性和准确性。此外，RK 对极端数据的估计能力优于 MLR 和 OK。正确使用 RK 确定地下水硝酸盐氮分布对于管理环境资源和预防公共健康危害非常有用。
