N and P behaviour in alluvial aquifers and in the soil solution of their catchment areas: How land use and the physical environment contribute to diffuse pollution

• DOI: 10.1016/j.scitotenv.2021.150056
• Publication Date: 2021-09-01T15:04:42Z
• Authors: Mercedes Arauzo; María Valladolid; Gema García; Delia M. Andries
• Keywords: Groundwater Pollution

The role of land use and the physical environment in N P pollution alluvial aquifers was analysed at three levels information: (1) aquifer (N groundwater), (2) soil transect (potentially leachable solution) (3) aquifer's catchment area. study carried out Oja Tirón their areas (northern Spain). Nitrate dominant form, both groundwater solution aquifers' areas. Orthophosphate organic-P were codominant forms aquifers. main form solution. During period 2005-2017 no significant decrease nitrate observed, suggesting need to review current Vulnerable Zone (NVZ) designations. Since is highly mobile, it tended accumulate stagnation zones lower reaches did not same due its low solubility. Principal component analyses (PCAs) aquifers, transects revealed that observation scale influences environmental factors can be detected as intervening pollution. At scale, links found between nitrates use, topographic, hydrogeological climatic factors. protective effect natural against noteworthy, while agriculture associated with an altitudinal gradient governed particle size distribution separating mountain forest soils from agricultural soils. negative relationship clay contents vs. orthophosphate pointed a regulatory clay. characteristics catchments determined macronutrient availability and, turn, distribution.