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Phosphorus Export Risk Matrix: Example 2

Example 2

Groundwater dominated system with low-medium risk of phosphorus reaching receiving channels.

Many of the factors influencing nutrient loss in surface water systems are the same for groundwater systems. In the diagram below a groundwater system is considered as an area with high infiltration soil, usually without land drains, underlain by porous bedrock such as chalk, limestone or coarse sandstone.

The prime factor influencing phosphorus loss in such a system is the hydrological connection of the regional aquifer with the surface water channels. Low-medium risk example is characterised by very little lateral flow resulting in near vertical percolation.

Note. This system may be loading the regional groundwater with nutrients. The low-medium risk refers only to the likelihood of phosphorus reaching the surface water – it does not mean that the aquifer is not at risk of long term nutrient loading. All best practice options that minimise the nutrient available to loading should still be pursued.

medium risk medium risk medium-high risk high risk high risk high risk high risk very high risk very high risk very high risk
medium risk medium risk medium risk medium-high risk high risk high risk high risk high risk very high risk very high risk
medium risk medium risk medium risk medium risk medium-high risk high risk high risk high risk high risk very high risk
medium risk medium risk medium risk medium risk medium risk medium-high risk high risk high risk high risk high risk
medium risk medium risk medium risk medium risk medium risk medium risk medium-high risk high risk high risk high risk
low-medium risk medium risk medium risk medium risk medium risk medium risk medium risk medium-high risk high risk high risk
low-medium risk low-medium risk medium risk medium risk medium risk medium risk medium risk medium risk medium-high risk high risk
low risk low risk low-medium risk medium risk medium risk medium risk medium risk medium risk medium risk medium-high risk
very low risk low risk low risk low-medium risk medium risk medium risk medium risk medium risk medium risk medium risk
very low risk very low risk low risk low-medium risk low-medium risk medium risk medium risk medium risk medium risk medium risk



High flow-connectivity, high risk due to fertiliser application


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© C J M Hewett, 2004 © University of Sheffield, University of Newcastle upon Tyne & Lancaster University 2001, 2004 and 2005
Last updated March 2005

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