Estimation of nitrogen and phosphorus losses to surface water and groundwater through the implementation of the SWAT model for Norwegian soils

Panagopoulos, I; Mimikou, M; Kapetanaki, M

dc.contributor.author	Panagopoulos, I	en
dc.contributor.author	Mimikou, M	en
dc.contributor.author	Kapetanaki, M	en
dc.date.accessioned	2014-03-01T01:26:18Z
dc.date.available	2014-03-01T01:26:18Z
dc.date.issued	2007	en
dc.identifier.issn	1439-0108	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17997
dc.subject	Coarse-textured soils	en
dc.subject	Diffuse losses	en
dc.subject	Fine-textured soils	en
dc.subject	Freezing soils	en
dc.subject	Nitrates	en
dc.subject	Nitrogen	en
dc.subject	Phosphorus	en
dc.subject	Runoff	en
dc.subject	Sediments	en
dc.subject	SWAT	en
dc.subject.classification	Geosciences, Multidisciplinary	en
dc.subject.classification	Soil Science	en
dc.subject.other	climate conditions	en
dc.subject.other	estimation method	en
dc.subject.other	groundwater	en
dc.subject.other	infiltration	en
dc.subject.other	leaching	en
dc.subject.other	nitrate	en
dc.subject.other	nitrogen	en
dc.subject.other	nutrient loss	en
dc.subject.other	phosphorus	en
dc.subject.other	runoff	en
dc.subject.other	sensitivity analysis	en
dc.subject.other	soil water	en
dc.subject.other	surface water	en
dc.subject.other	texture	en
dc.subject.other	transport process	en
dc.subject.other	Avena	en
dc.subject.other	Hordeum	en
dc.subject.other	Triticum aestivum	en
dc.title	Estimation of nitrogen and phosphorus losses to surface water and groundwater through the implementation of the SWAT model for Norwegian soils	en
heal.type	journalArticle	en
heal.identifier.primary	10.1065/jss2007.04.219	en
heal.identifier.secondary	http://dx.doi.org/10.1065/jss2007.04.219	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Scope and Background. It is acknowledged that diffuse sources cause the most important nitrogen (N) and phosphorus (P) losses to the river system and substantially enrich the groundwater in nitrates. These losses arise primary from agricultural activities mainly fertilizer applications, and they are determined by soil attributes. In cold climates, winter conditions and freezing of soils may influence the infiltration capacity of the soil and thereby can have a serious effect on the partitioning of excess precipitation and subsequently on the soil and nutrient transportation. The purpose of this article is to investigate the behaviour of six widespread and different textured soil types, on nutrient (N, P) losses under cold climate conditions. The investigation was conducted in the Norwegian Vansjø-Hobølv catchment through the application of a physical model named Soil and Water Assessment Tool (SWAT), taking into consideration the additional aspect of freezing soils during winter, which distinguishes Scandinavian from other European soils. Methods. SWAT is a physical river basin model that was developed for the U.S.D.A. Agricultural Research Service, by the Blackland Research Center in Texas. In the current modeling approach the catchment was divided into 43 Hydrologic Response Units (HRUs) which consist of different combinations of the existed landcover and soil types. Nitrogen and phosphorus losses arising from these HRUs were estimated for the period 1990-2001 through the simultaneous simulation of water and sediment processes that are closely linked to the nutrient processes. The model took into account soil temperature in order to quantify water and nutrient transport to deeper layers, considering negligible downward movement when the soil temperature was under 0°C. It also simulated the aboveground development of the snowpack and the snowmelt processes on a daily basis. The six different soil types were distinguished in two groups according to their similarity in texture and other physical properties, one group of fine-textured soils and a group of coarse soils. The results were evaluated for different crop cultivations (barley, oats and wheat) of the aforementioned soils. Finally, the model was calibrated and validated by comparing predicted results with measured data. Results and Discussion. Fine-textured soils caused significant runoff, sediment, total nitrogen (TN) and total phosphorus (TP) yields to the river system while coarser soils were characterized by high water drainage and nitrates leaching. The first soil group caused a mean of 517 mm of runoff in annual basis, 200 mm higher than this arising from coarse soils. Moreover, 3 tonnes of sediments per hectare, 24.6 kgN/ha and 0.54 kgP/ha were lost annually to surface water from fine soils while the average respective losses originating from coarse soils were only 1.3 tn of sediments/ha, 13.6kgN/ha and 0.17kgP/ha. The sensitivity ranking of the soil types to TN and TP losses was silty-clayloam>silty-loam> clay>loamy>sandy-loam>sandy. An average of 277 mm of water was percolated annually under the bottom of the soil profile in coarse soils causing the additional leaching of 5.6 kgN-NO3/ha whereas the losses originating from fine-textured soils were 153 mm and 2.5 kg/ha respectively. According to their sensitivity in nitrates leaching, the six soil types were ranked in the following order: sandy>loamy>sandy-loam>silty-loam>silty-clay-loam>clay. Conclusions and Perspectives. The results showed that even though under cold climate conditions, with monthly periods of average air-temperatures below zero, the overall amounts of annual TN and TP losses to surface waters as well as nitrates leaching to groundwater were considerable. This demonstrates that the cold climate conditions did not affect the long-term behavior of the six widespread Norwegian soils, which on an annual basis responded similarly to the respective European soils. According to the model's estimations, infiltration with N and P transport still occur in wintertime, and comparing to other studies that reported similar results, different possible explanations were considered. The results demonstrate the need of considering the soil differentiation in Scandinavian countries similarly to the rest of Europe in order to apply mitigation measures against nitrogen and phosphorus losses to surface and groundwater. © 2007 ecomed publishers (Verlagsgruppe Hüthig Jehle Rehm GmbH).	en
heal.publisher	ECOMED PUBLISHERS	en
heal.journalName	Journal of Soils and Sediments	en
dc.identifier.doi	10.1065/jss2007.04.219	en
dc.identifier.isi	ISI:000248864200004	en
dc.identifier.volume	7	en
dc.identifier.issue	4	en
dc.identifier.spage	223	en
dc.identifier.epage	231	en