A comparison of SWAT, HSPF and SHETRAN/GOPC for modelling phosphorus export from three catchments in Ireland

Abstract

1Recent extensive water quality surveys in Ireland revealed that diffuse phosphorus (P) 2 pollution originating from agricultural land and transported by runoff and subsurface 3 flows is the primary cause of the deterioration of surface water quality. P transport from 4 land to water can be described by mathematical models that vary in modelling approach,

A review of phosphorus and sediment release from Irish tillage soils, the methods used to quantify losses and the current state of mitigation practice

“…Modelling of diffuse P loss from grassland catchments has also been undertaken by Jordan et al (2000), Daly et al (2002), Scanlon et al (2005) and Nasr et al (2007), with the aim of improving management strategies to minimise P loss. Tillage soils are, however, more susceptible to water erosion than grassland soils (Van Oost et al 2009) due to greater soil surface exposure to erosive forces during fallow and planting periods (Lal 2001) and soil disturbance by tillage operations (Lal 2001), which alters its structure.…”

“…Complex physical models applied with the necessary expertise or user support can be far superior where there is a need to address spatial and temporal complexities (Irvine et al 2005). According to the Drivers, Pressures, State, Impact and Response (DPSIR) conceptual framework (Irvine et al 2005) that guides the selection of modelling techniques in Ireland, it is likely that the most useful models will be of the physically-based or mechanistic type (Nasr et al 2007). Nasr et al (2007) tested three widely-used physically-based models (SWAT, HSPF and SHETRAN, coupled with the grid-orientated P component (GOPC; Nasr et al 2005) of diffuse P pollution, in three Irish grassland catchments in order to explore their suitability in Irish conditions for future use in implementing the WFD.…”

“…According to the Drivers, Pressures, State, Impact and Response (DPSIR) conceptual framework (Irvine et al 2005) that guides the selection of modelling techniques in Ireland, it is likely that the most useful models will be of the physically-based or mechanistic type (Nasr et al 2007). Nasr et al (2007) tested three widely-used physically-based models (SWAT, HSPF and SHETRAN, coupled with the grid-orientated P component (GOPC; Nasr et al 2005) of diffuse P pollution, in three Irish grassland catchments in order to explore their suitability in Irish conditions for future use in implementing the WFD. These models range from semi-empirical (SWAT) to fully physically-based (SHETRAN/GOPC) in how they represent the relevant hydrological, chemical and biochemical processes transforming the P compounds both in the soil and during their transport by water (Nasr et al 2007).…”

“…Nasr et al (2007) tested three widely-used physically-based models (SWAT, HSPF and SHETRAN, coupled with the grid-orientated P component (GOPC; Nasr et al 2005) of diffuse P pollution, in three Irish grassland catchments in order to explore their suitability in Irish conditions for future use in implementing the WFD. These models range from semi-empirical (SWAT) to fully physically-based (SHETRAN/GOPC) in how they represent the relevant hydrological, chemical and biochemical processes transforming the P compounds both in the soil and during their transport by water (Nasr et al 2007). The catchments were selected based on data availability and different climates, land use and soil type.…”

A Review of Modelling Tools for Implementation of the EU Water Framework Directive in Handling Diffuse Water Pollution

“…Therefore, the factors of application scale, contaminant simulation capability, nutrient cycling processes in soil, climate change response, pervious and impervious shallow geology, land use supporting, etc., should be considered in choosing a numerical catchment water modelling tool for better implementation of the EU WFD in handling DWP. Some modelling comparison literatures can be found, for example Nasr et al (2007) studied phosphorus export modelling at catchment scale; majority of work was done about specific modelling effort from various, diverse models for various DWP issues from agricultural nutrient loading, coastal water quality assessment (Yuan et al, 2007;Krause et al, 2008), to detailed contribution from root system and large scale transboundary modelling (Diogo et al, 2008;Sohier et al, 2009). This paper aims to 1) critically review the popular water models in selecting a proper numerical tool for better implementation of the EU WFD in modelling DWP; 2) assess a selected model -Hydrological Simulation Program -FORTRAN (HSPF) by applying it in water quantity and nutrient quality modelling; 3) present a case study with HSPF model in the Upper Bann Catchment, Northern Ireland; and 4) evaluate the impact of DWP management strategies on water quality.…”