Validation and modification of the phosphorus loss index as applied to a small catchment

Abstract

Environmental legislation in many countries requires the development of phosphorus indices to determine the risk of P loss from soils to water. The concentrations of total phosphorus (TP), molybdate-reactive phosphorus (MRP) and particulate phosphorus (PP) and the movement of these P forms were determined in a small catchment in Galicia (north-west Spain) with the aim of establishing an index of P loss. The discharges and concentrations of the different P forms were measured at different points in the river basin. The information was used to estimate the accuracy of a P index derived from the model described by Gburek et al. (2000). The amount of P lost over the 5-month period of study was ca. 60 g ⁄ ha; in essence, the overall loss was low. The P losses differed throughout the study period and between sampling points, and some areas of the catchment acted as P sinks. This was probably associated with the transport of deposited material by the rivers. Of the two components included in the index, the source factor was consistent with the source areas in the catchment as identified by water analysis. However, the transport factor was not very consistent with the field data and must be reconsidered.

Estimación del factor de transporte del índice de fósforo con climatologías y escenarios de cambio climático en tierras de Jalisco, México

“…Se utilizaron los componentes del Factor de Transporte Índice de Fósforo (FTIP) de Gburek et al (11) . El valor del FTIP obtenido varía de 0 a 1, con nivel de vulnerabilidad muy bajo cuando FTIP es menor a 0.15, bajo de 0.15 a 0.3, medio de 0.3 a 0.5, alto de 0.5 a 0.8 y muy alto mayor que 0.8 (24) .…”

Phosphorus in soils and its transfer to water: from fine‐scale soil processes to models and solutions in landscapes and catchments

“…Models provide a means to rationalize and attempt to overcome the complexities of the larger scale land-water connections. Vadas et al (2013) provides a useful overview on his critical evaluation of models, with Dechmi et al (2013) and Troitiño et al (2013) developing the classic Pindex approach started by Lemunyon & Gilbert (1993), but here for local European conditions. Farkas et al (2013) uses the INCA model to determine soil erosion and P losses under variable land use, whilst Schoumans et al (2013) proposes a simple model that focuses on P leaching.…”

“…() and Troitiño et al . () developing the classic P – index approach started by Lemunyon & Gilbert (), but here for local European conditions. Farkas et al .…”