Water quality dynamics and hydrology in nitrate loaded riparian zones in the Netherlands

• Published in: Environmental pollution (1987) Vol. 139; no. 1; pp. 143 - 156
• Main Authors: Hefting, Mariet, Beltman, Boudewijn, Karssenberg, Derek, Rebel, Karin, van Riessen, Mirjam, Spijker, Maarten
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2006; Elsevier
• Subjects: agricultural runoff; Agronomy. Soil science and plant productions; analysis; Applied sciences; biodegradation; Biological and medical sciences; Biological and physicochemical phenomena; chemistry; denitrification; Dilution; Earth sciences; Earth, ocean, space; Ecosystem; Engineering and environment geology. Geothermics; Environmental Monitoring; Environmental Monitoring - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Geological Phenomena; Geology; grasslands; Groundwater; groundwater contamination; methods; N-saturation; Natural water pollution; Netherlands; nitrate nitrogen; Nitrate removal; Nitrates; Nitrates - analysis; Nitrogen; Nitrogen - analysis; Osmolar Concentration; Poaceae; Pollution; pollution load; Pollution, environment geology; Rain; riparian areas; riparian forests; Riparian wetlands; Rivers; Rivers - chemistry; Soil and water pollution; Soil Pollutants; Soil Pollutants - analysis; Soil science; Trees; water flow; Water Movements; Water Pollutants, Chemical; Water Pollutants, Chemical - analysis; water quality; Water treatment and pollution; wetlands; Netherlands; Europe; Nitrate removal; Dilution; Groundwater; N-saturation; Riparian wetlands; Grassland; Forests; Pollution control; Pollution prevention; Nitrates; Agricultural soil; Runoff water; Nitrogen; Hydrology; Hydrochemistry; Selfpurification; Riparian; Surface water; Water quality; Stream; Water pollution; Performance; Wetland; Ground water
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2005.04.023

Riparian zones are known to function as buffers, reducing non-point source pollution from agricultural land to streams. In the Netherlands, riparian zones are subject to high nitrogen inputs. We combined hydrological, chemical and soil profile data with groundwater modelling to evaluate whether chronically N loaded riparian zones were still mitigating diffuse nitrate fluxes. Hydraulic parameters and water quality were monitored over 2 years in 50 piezometres in a forested and grassland riparian zone. Average nitrate loadings were high in the forested zone with 87 g NO 3 −-N m −2 y −1 and significantly lower in the grassland zone with 15 g NO 3 −-N m −2 y −1. Groundwater from a second aquifer diluted the nitrate loaded agricultural runoff. Biological N removal however occurred in both riparian zones, the grassland zone removed about 63% of the incoming nitrate load, whereas in the forested zone clear symptoms of saturation were visible and only 38% of the nitrate load was removed. Riparian zones reduced nitrate from agricultural lands.