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Climate Change and the European Water Dimension - Agri ...

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Nitrogen emission [Mg y -1 ]<br />

Nitrogen emission [Mg y -1 ]<br />

Nitrogen emission [Mg y -1 ]<br />

Nitrogen emission [Mg y -1 ]<br />

Nitrogen emission [Mg y -1 ]<br />

significant contribution (35% of <strong>the</strong> total). Phosphorus is released primarily by<br />

WWTPs <strong>and</strong> urban systems (64%), but <strong>the</strong> erosion, tile drainage <strong>and</strong> groundwater<br />

pathways are significant (31%). The modelling process shows, as expected, <strong>the</strong><br />

strong dependence of nutrient fluxes on <strong>the</strong> water balance.<br />

Table-VI.C.6: Assumptions adopted for <strong>the</strong> A, B, C scenarios for<br />

modelling nutrients dynamics in <strong>the</strong> Po Catchment.<br />

Scenario Hypo<strong>the</strong>sis 2025 2050 2100<br />

A<br />

Variation of Continental<br />

precipitation. [mm day -1 ]<br />

Heavy precipitation<br />

events:<br />

-0,25 -0,35 -0,50<br />

B % Increase in number of<br />

days with storm water<br />

events.<br />

Variation of maximum<br />

+15 % +30% +50%<br />

C Groundwater recharge<br />

value. [mm]<br />

1500 1000 700<br />

The selected scenarios hereafter analysed were based on IPCC scenarios (IPCC,<br />

2001) assuming a doubling of atmospheric CO2 by 2030. These scenarios were<br />

based on <strong>the</strong> projection of<br />

<strong>Change</strong>s in Total Emission<br />

<strong>Change</strong>s in Total Emission<br />

selected key parameters<br />

262,969<br />

- 2 %<br />

- 2.2%<br />

Nitrogen<br />

10,386<br />

- 0,2 % - 0,2% Phosophorus<br />

- 1%<br />

including temperature,<br />

precipitation, wind, air<br />

- 4.5%<br />

humidity, soil moisture as<br />

suggested in IPCC (2001)<br />

2000 2025 2050 2100<br />

2000 2025 2050 2100<br />

<strong>and</strong> detailed in Table-<br />

Emission <strong>Change</strong>s in Groundwater Pathway<br />

Emission <strong>Change</strong>s in Groundwater Pathway VI.C.5 <strong>and</strong> Table-VI.C.6.<br />

95,830<br />

- 4.9 %<br />

- 6,1%<br />

- 12%<br />

2000 2025 2050 2100<br />

Emission <strong>Change</strong>s in Overl<strong>and</strong> Flow Pathway<br />

4169<br />

- 8 %<br />

- 11%<br />

- 16%<br />

2000 2025 2050 2100<br />

Emission <strong>Change</strong>s in Urban System Pathway<br />

24,091<br />

- 2 %<br />

- 1,4%<br />

- 1,6%<br />

2000 2025 2050 2100<br />

959<br />

Emission <strong>Change</strong>s in Erosion Pathway<br />

- 1,3 %<br />

- 2%<br />

- 3%<br />

2000 2025 2050 2100<br />

Phosphorous emission [Mg y -1 ]<br />

Phosphorous emission [Mg y -1 ]<br />

Phosphorous emission [Mg y -1 ]<br />

Phosphorous emission [Mg y -1 ]<br />

862<br />

- 0,9 %<br />

- 2,4%<br />

186<br />

- 5,2%<br />

2000 2025 2050 2100<br />

Emission <strong>Change</strong>s in Overl<strong>and</strong> flow Pathway<br />

383<br />

- 0,9 %<br />

- 2,4%<br />

- 5,2%<br />

2000 2025 2050 2100<br />

Emission <strong>Change</strong>s in Urban System Pathway<br />

3,010<br />

-1,9 % - 1,7% - 1,4%<br />

2000 2025 2050 2100<br />

836<br />

Emission<strong>Change</strong>s in Erosion Pathway<br />

-1,3 %<br />

- 2%<br />

- 3%<br />

2000 2025 2050 2100<br />

Figure-VI.C.8: Effects of precipitation changes on nutrients<br />

emission assuming <strong>the</strong> 2001 as reference year.<br />

Phosphorous emission [Mg y -1 ]<br />

Scenario A<br />

Projected total emission<br />

(in 2100) of nitrogen<br />

<strong>and</strong> phosphorus show a<br />

4.5% <strong>and</strong> 1% reduction,<br />

respectively. Although <strong>the</strong><br />

overall N <strong>and</strong> P projected<br />

reductions are small <strong>the</strong>ir<br />

relative variation for each<br />

transport pathway can be<br />

substantial.<br />

Transport by <strong>the</strong> overl<strong>and</strong><br />

flow <strong>and</strong> groundwater<br />

pathways show a relevant<br />

decrease for both nutrients<br />

with a decrease in<br />

precipitation, this effect is<br />

primarily caused by a<br />

reduction of runoff into<br />

rivers affecting <strong>the</strong><br />

nitrogen mobility within <strong>the</strong><br />

soil. Meanwhile, <strong>the</strong> urban

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