2 research outputs found
Drainage water quality and end-member identification in La Violada irrigation district (Spain)
32 Pag., 9 Fig., 5 Tabl. The definitive version is available at: http://www.sciencedirect.com/science/journal/00221694The identification of the different components in a water course is required to individualize and assess
the actual contribution of irrigated agriculture to the pollution of the water course. This paper aimed
at identifying and assessing the composition of the end-members in La Violada irrigation district (VID)
and establishing a statistical procedure to reduce the sampling effort needed to establish drainage water
quality. The quality of irrigation water, groundwater, and irrigated-land drainage water in VID was monitored
during three hydrologic years to identify the components of flow in La Violada Gully, the natural
exit course of VID. A network of sampling points in the secondary ditches and main drains of VID allowed
identifying and separating those collecting irrigated-land drainage waters from those conveying high
proportions of irrigation waters. Three end-member flows were identified in La Violada Gully during
the irrigation season: (a) irrigation water arising from tail-waters, leakages and spills from the irrigation
canals, very low in salts; (b) groundwater originating from the non-irrigated upper reaches of La Violada
Gully watershed, high in Cl and Na+; and (c) VID drainage water, high in SO2
4 and Ca2+. The overall VID
drainage water quality was accurately assessed through a simplified sampling scheme of only four sampling
points that produced low errors of 0.1 dS/m for EC and 0.1 mmolc/L for Cl . The separation of La Violada
Gully flow in these three components is essential for estimating the actual contribution of irrigation
in VID to the salt and nitrogen loads in La Violada Gully.This work was funded by the Spanish Institute of Agricultural Research and
Technology (Project INIA SC95-031) and the European Union (Project INCO CT-2005-015031). The Spanish Institute of Agricultural Research and Technology provided
a fellowship for the first author.Peer reviewe
Drainage water quality and end-member identification in La Violada irrigation district (Spain)
32 Pag., 9 Fig., 5 Tabl. The definitive version is available at: http://www.sciencedirect.com/science/journal/00221694The identification of the different components in a water course is required to individualize and assess
the actual contribution of irrigated agriculture to the pollution of the water course. This paper aimed
at identifying and assessing the composition of the end-members in La Violada irrigation district (VID)
and establishing a statistical procedure to reduce the sampling effort needed to establish drainage water
quality. The quality of irrigation water, groundwater, and irrigated-land drainage water in VID was monitored
during three hydrologic years to identify the components of flow in La Violada Gully, the natural
exit course of VID. A network of sampling points in the secondary ditches and main drains of VID allowed
identifying and separating those collecting irrigated-land drainage waters from those conveying high
proportions of irrigation waters. Three end-member flows were identified in La Violada Gully during
the irrigation season: (a) irrigation water arising from tail-waters, leakages and spills from the irrigation
canals, very low in salts; (b) groundwater originating from the non-irrigated upper reaches of La Violada
Gully watershed, high in Cl and Na+; and (c) VID drainage water, high in SO2
4 and Ca2+. The overall VID
drainage water quality was accurately assessed through a simplified sampling scheme of only four sampling
points that produced low errors of 0.1 dS/m for EC and 0.1 mmolc/L for Cl . The separation of La Violada
Gully flow in these three components is essential for estimating the actual contribution of irrigation
in VID to the salt and nitrogen loads in La Violada Gully.This work was funded by the Spanish Institute of Agricultural Research and
Technology (Project INIA SC95-031) and the European Union (Project INCO CT-2005-015031). The Spanish Institute of Agricultural Research and Technology provided
a fellowship for the first author.Peer reviewe