Spatial Quantification of Non-Point Source Pollution in a Meso-Scale Catchment for an Assessment of Buffer Zones Efficiency

Water

Mikoᐪj Piniewski²  Paweł Marcinkowski²  Ignacy Kardel²  Marek Gieᐬzewski²  Katarzyna Izydorczyk¹  Wojciech Fratczak¹  Lutz Breuer³ 

[1] European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Tylna str. 3, Łódź 90-364, Poland; E-Mails:;Department of Hydraulic Engineering, Warsaw University of Life Sciences (WULS-SGGW), Nowoursynowska str. 159, Warszawa 02-776, Poland; E-Mails:Department of Hydraulic Engineering, Warsaw University of Life Sciences (WULS-SGGW), Nowoursynowska str. 159, Warszawa 02-776, Poland;

关键词: water quality;    nutrient;    ecotones;    vegetative filter strips;    buffer strips;    hydrological model;    Pilica;    diffuse pollution;   

DOI  :  10.3390/w7051889

来源: mdpi

【 摘 要 】

The objective of this paper was to spatially quantify diffuse pollution sources and estimate the potential efficiency of applying riparian buffer zones as a conservation practice for mitigating chemical pollutant losses. This study was conducted using a semi-distributed Soil and Water Assessment Tool (SWAT) model that underwent extensive calibration and validation in the Sulejów Reservoir catchment (SRC), which occupies 4900 km² in central Poland. The model was calibrated and validated against daily discharges (10 gauges), NO₃–N and TP loads (7 gauges). Overall, the model generally performed well during the calibration period but not during the validation period for simulating discharge and loading of NO₃–N and TP. Diffuse agricultural sources appeared to be the main contributors to the elevated NO₃–N and TP loads in the streams. The existing, default representation of buffer zones in SWAT uses a VFS sub-model that only affects the contaminants present in surface runoff. The results of an extensive monitoring program carried out in 2011–2013 in the SRC suggest that buffer zones are highly efficient for reducing NO₃–N and TP concentrations in shallow groundwater. On average, reductions of 56% and 76% were observed, respectively. An improved simulation of buffer zones in SWAT was achieved through empirical upscaling of the measurement results. The mean values of the sub-basin level reductions are 0.16 kg NO₃/ha (5.9%) and 0.03 kg TP/ha (19.4%). The buffer zones simulated using this approach contributed 24% for NO₃–N and 54% for TP to the total achieved mean reduction at the sub-basin level. This result suggests that additional measures are needed to achieve acceptable water quality status in all water bodies of the SRC, despite the fact that the buffer zones have a high potential for reducing contaminant emissions.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland