2. CAPITULO II: ANALISIS DEL CONTEXTO DE LA ORGANIZACIÓN
2.1. Análisis DOFA
intensively managed grassland catchment caused by a summer storm. Water Air Soil Pollution 205: 377-393. 711
doi:10.1007/s11270-009-0083-z. 712
Griffith, B., J. Hawkins, M.B.,, R.J. Orr, M.S.A. Blackwell and P.J. Murray. 2013. The North Wyke Farm Platform: 713
Methodologies used in remote sensing of the water quantity and quality of drainage water. Int. Grass. Congr. 714
Sydney, Australia. 715
Harrod, T.R. and D.V. Hogan. 2008. The soils of North Wyke and Rowden. 716
http://www.northwyke.bbsrc.ac.uk/pages/soilsofnw.html. 717
Hawkins, J.M.B. and D. Scholefield. 1996. Molybdate-reactive phosphorus losses in surface and drainage waters from 718
permanent grassland. J. Environ. Qual. 25: 727-732. doi:10.2134/jeq1996.00472425002500040012x. 719
Haygarth, P., B.L. Turner, A. Fraser, S. Jarvis, T. Harrod, D. Nash, D. Halliwell, R. Page and K. Beven. 2004. Temporal 720
variability in phosphorus transfers: classifying concentration-discharge event dynamics. Hydrol. Earth Syst. Sci. 721
8: 88-97. doi:10.5194/hess-8-88-2004. 722
Haygarth, P.M. and S.C. Jarvis. 1997. Soil derived phosphorus in surface runoff from grazed grassland lysimeters. 723
Water Res. 31: 140-148. doi:10.1016/S0043-1354(99)80002-5. 724
Haygarth, P.M., L.M. Condron, A.L. Heathwaite, B.L. Turner and G.P. Harris. 2005a. The phosphorus transfer 725
continuum: linking source to impact with an interdisciplinary and multi-scale approach. Sci. Total Environ. 344: 726
5-14. doi:10.1016/j.scitotenv.2005.02.001. 727
Haygarth, P.M., F.L. Wood, A.L. Heathwaite and P.J. Butler. 2005b. Phosphorus dynamics observed through increasing 728
scales in a nested headwater-to-river channel study. Sci. Total Environ. 344: 83-106. 729
doi:10.1016/j.scitotenv.2005.02.007. 730
Heathwaite, A.L., P.F. Quinn and C.J.M. Hewett. 2005. Modelling and managing critical source areas of diffuse pollution 731
from agricultural land using flow connectivity simulation. J. Hydrol. 304: 446-461. 732
doi:10.1016/j.jhydrol.2004.07.043. 733
Heitkamp, F., J. Paupp and B. Ludwig. 2009. Impact of fertiliser type and rate on carbon and nitrogen pools in a sandy 734
For Review Only
Hope, D., M.F. Billett and M.S. Cresser. 1997a. Exports of organic carbon in two river systems in NE Scotland. J. 736
Hydrol. 193: 61-82. doi:10.1016/S0022-1694(96)03150-2. 737
Hope, D., M.F. Billett, R. Milne and T.A.W. Brown. 1997b. Exports of organic carbon in British rivers. Hydrol. Processes 738
11: 325-344. doi:10.1002/(SICI)1099-1085(19970315)11. 739
House, W.A. and M.S. Warwick. 1998. Hysteresis of the solute concentration/ discharge relationship in rivers during 740
storms. Water Res. 32: 2279-2290. doi:10.1016/S0043-1354(97)00473-9. 741
Hughes, G., E. Lord, L. Wilson, R. Gooday and S.G. Anthony. 2008. Updating previous estimates of the load and 742
source apportionment of nitrogen to waters in the UK. In: DEFRA, editor. 743
Jarvie, H.P., P.M. Haygarth, C. Neal, C. Butler, B. Smith, P.S. Naden, A. Joynes, M. Neal, H. Wickham, L. Armstrong, S. 744
Harman and E.J. Palmer-Felgate. 2008. Stream water chemistry and quality along an upland-lowland rural land- 745
use continuum, south-west England. J. Hydrol. 350: 215-231. doi:10.1016/j.jhydrol.2007.10.040. 746
Jordan, P., A. Arnscheidt, H. Mcgrogan and S. Mccormick. 2007. Characterising phosphorus transfers in rural 747
catchments using a continuous bank-side analyser. Hydrology and Earth System Sciences Discussions 11: 372- 748
381. doi:10.5194/hess-11-372-2007. 749
Jordan, P. and R. Cassidy. 2011. Technical Note: Assessing a 24/7 solution for monitoring water quality loads in small 750
river catchments. Hydrol. Earth Syst. Sci. 15: 3093-3100. doi:10.5194/hess-15-3093-201.
751
Jordan, P., A.R. Melland, P.-E. Mellander, G. Shortle and D. Wall. 2012. The seasonality of phosphorus transfers from 752
land to water: Implications for trophic impacts and policy evaluation. Sci. Total Environ. 434: 101-109. 753
doi:10.1016/j.scitotenv.2011.12.070. 754
Kirchner, J.W., X. Feng, C. Neal and A.J. Robson. 2004. The fine structure of water-quality dynamics: the (high- 755
frequency) wave of the future. Hydrol. Processes 18: 1353-1359. doi:10.1002/hyp.5537. 756
Klein, M. 1984. Anti-clockwise hysteresis in suspended sediment concentration during individual storms: Holbeck 757
catchment, Yorkshire, England. CATENA 11: 251-257. doi:10.1016/S0341-8162(84)80024-7. 758
Kronvang, B., A. Laubel and R. Grant. 1997. Suspended sediment and particulate phosphorus transport andd elivery 759
pathways in an arable catchment, Gelbaek Stream, Denmark. Hydrol. Processes 11: 672-642. 760
Lewis, W.M. and D.P. Morris. 1986. Toxicity of nitrite to fish: a review. Transactions of the American Fishery Society 761
115: 183-195. doi:10.1577/1548-8659(1986)115<183. 762
Littlewood, I.G. 1992. Estimating Contaminant Loads in Rivers: a review. Institute of Hydrology, Wallingford, UK. p. 81. 763
Maier, G., G.a. Glegg, A.D. Tappin and P.J. Worsfold. 2012. A high resolution temporal study of phytoplankton bloom 764
dynamics in the eutrophic Taw Estuary (SW England). Sci. Total Environ. 434. 765
doi:10.1016/j.marpolbul.2009.02.014. 766
McGonigle, D.F., R.C. Harris, C. McCamphill, S. Kirk, R. Dils, J. Macdonald and S. Bailey. 2012. Towards a more 767
strategic approach to research to support catchment-based policy approaches to mitigate agricultural water 768
pollution: A UK case-study. Environ. Sci. Policy 24: 4-14. doi:10.1016/j.envsci.2012.07.016. 769
Nash, D., M. Hannah, D. Halliwell and C. Murdoch. 2000. Factors affecting phosphorus export from a pasture based 770
grazing system. J. Environ. Qual. 29: 1160-1165. doi:10.2134/jeq2000.00472425002900040017x. 771
Parris, K. 2011. Impact of agriculture on water pollution in OECD countries: recent trends and future prospects. 772
For Review Only
Peeters, A. 2004. Wild and sown grasses. Profiles of a temperate species selection; Ecology, Biodiversity and Use. 774
Blackwell, London. 775
Peukert, S., R. Bol, W. Roberts, C. Macleod, J.A., , P.J. Murray, E.R. Dixon and R.E. Brazier. 2012. Understanding 776
spatial variability of soil properties: a key step in establishing field- to farm-scale agro-ecosystem experiments. 777
Rapid Commun. Mass Spectron. 26: 2413-2421. doi:10.1002/rcm.6336. 778
Pilgrim, E.S., Macleod, J.A. Ch, S.A. Blackwell, R. Bol, D.V. Hogan, D.R. Chadwick, L. Cardenas, T.H. Misslebrook, P.M. 779
Haygarth, R.E. Brazier, P. Hobbs, C. Hodgson, S. Jarvis, J. Dungait, P. Murray and L.G. Firbank. 2010. Interaction 780
among agricultural production and other ecosystem services delivered from European temperate grassland 781
systems. Adv. Agron. 109: 117-154. doi:10.1016/B978-0-12-385040-9.00004-9 782
Preedy, N., K. McTiernan, R. Matthews, L. Heathwaite and P. Haygarth. 2001. Rapid incidental phosphorus transfer 783
from grassland. J. Environ. Qual. 30: 2105-2112. doi:10.2134/jeq2001.2105. 784
Quinton, J.N., J.A. Catt, G.A. Wood and J. Steer. 2006. Soil carbon losses by water erosion: Experimentation and 785
modelling at field and national scales in the UK. Agric., Ecosyst. Environ. 112: 87-102. 786
doi:10.1016/j.agee.2005.07.005. 787
Quinton, J.N., G. Govers, K. Van Oost and R.D. Bardgett. 2010. The impact of agricultural soil erosion on 788
biogeochemical cycling. Nat. Geosci. 3. doi:10.1038/ngeo838. 789
Sandford, R.C., J.M.B. Hawkins, R. Bol and P.J. Worsfold. 2013. Export of dissolved organic carbon and nitrate from 790
grassland in winter using high temporal resolution, in situ UV sensing. Sci. Total Environ. 456-457. 791
doi:10.1016/j.scitotenv.2013.02.078. 792
Schilling, K.E., C. Jones, S., and A. Seeman. 2013. How paired is paired? comparing nitrate concentrations in three 793
Iowa drainage districts. J. Environ. Qual. 42: 1412-1421. 794
Scholefield, D., K.C. Tyson, E.A. Garwood, A.C. Armstrong, J. Hawkins and A.C. Stone. 1996. Nitrate leaching from 795
grazed grassland lysimeters: effects of fertiliser input, field drainage, age of sward and patterns of weather. J. 796
Soil Sci. 44: 601-613. doi:10.1111/j.1365-2389.1993.tb02325.x. 797
See, J.H., D.A. Bronk and A.J. Lewitus. 2006. Uptake of Spartina-derived humic nitrogen by estuarine phytoplankton in 798
nonaxenic and axenic culture. Limnol. Oceanogr. 51: 2290-2299. doi:10.4319/lo.2006.51.5.2290. 799
Smith, K.A., D.R. Jackson and P.J.A. Withers. 2001. Nutrient losses by surface run-off following the application of 800
organic manures to arable land. 2. Phosphorus. Environ. Pollut. 112: 53-60. doi:10.1016/S0269-7491(00)00098-1. 801
Stutter, M.I., S.J. Langer and R.J. Cooper. 2008. Spatial and temporal dynamics of stream water particulate and 802
dissolved N, P and C forms along a catchment transect, NE Scotland. J. Hydrol. 350: 187-202. 803
doi:10.1016/j.jhydrol.2007.10.048. 804
TAG, U. 2008. UK Environmental standards and conditions (Phase 2). UK Technical Advisory Group on the Water 805
Framework Directive. 806
Thompson, J., R. Cassidy, D.G. Doody and R. Flynn. 2014. Assessing suspended sediment dynamics in relation to 807
ecological thresholds and sampling strategy in two Irish headwater catchments. Sci. Total Environ. 438-469: 345- 808
357. doi:10.1016/j.scitotenv.2013.08.069. 809
USEPA. 2000. Ecoregional Nutrient Criteria Documents for rivers and streams <http://www2.epa.gov/nutrient-policy- 810
For Review Only
Walling, D.E. and B.W. Webb. 1985. Estimating the discharge of contaminants to coastal waters by rivers- some 812
cautionary comments. Mar. Pollut. Bull. 16: 488-492. doi:10.1016/0025-326X(85)90382-0. 813
White, P.J. and J.P. Hammond. 2009. The source of phosphorus in the waters of Great Britain. J. Environ. Qual. 38: 13- 814
26. doi:10.2134/jeq2007.0658. 815
Withers, P.J.A., Hodgkinson R.A., A. Bates and C.M. Withers. 2006. Some effects of tramlines on surface runoff, 816
sediment and phosphorus mobilization on an erosion-prone soil. Soil Use Manage. 22: 245-255. 817
doi:10.1111/j.1475-2743.2006.00034.x. 818
Wood, F.L., A.L. Heathwaite and P.M. Haygarth. 2005. Evaluating diffuse and point phosphorus contributions to river 819
transfers at different scales in the Taw catchment, Devon, UK. J. Hydrol. 304: 118-138. 820
doi:10.1016/j.jhydrol.2004.07.026. 821
Worall, F., Davies, A. Bhogal, A. Lilly, M. Evans, K. Turner, T. Burt, D. Barraclough, P. Smith and G. Merrington. 2012. 822
The flux of DOC from the UK- Predicting the role of soils, land use and net watershed losses. J. Hydrol. 448-449: 823 149-160. doi:10.1016/j.jhydrol.2012.04.053. 824 825 826 827 828 829 830
Figure 1. Description of the sampling site: the North Wyke Farm Platform. a) 831
Location of the Farm Platform and b) the three sampling fields within the Farm 832
Platform. c) - e) individual sampling field topography, soil types, location of flumes, 833
rain gauges and soil moisture probes for Field 2 (6.71 ha), Field 5 (6.59 ha) and 834
Field 8 (7.59 ha), respectively. Names for soil types under international 835
classifications: Denbigh/ Cherubeer (Avery, 1980): FAO Stagni-eutric cambisol, 836
USDA: Dystic eutrochrept; Halstow (Avery, 1980): FAO Stagni-vertic cambisol, 837
USDA Aeric haplaquept; Halsworth (Avery, 1980): FAO Stagni-vertic cambisol, 838
USDA Typic haplaquept (in Harrod and Hogan, 2008). 839
For Review Only
Figure 2. Rainfall (mm hour-1), discharge (L s-1) and hydrological events for all three 840
intensively managed grassland sampling fields for the entire sampling duration (April 841
2012- April 2013). All data was monitored and is expressed at 15-minute time steps. 842
Hydrological events were defined on the basis of rainfall and a discharge response 843
rising above certain thresholds, based on field sizes. Occurrence of hydrological 844
events was also similar, but peak flow rates vary between the fields. Soil moisture 845
levels (not included in this figure) were high or near to saturation in mid-end of April, 846
mid-end of June and throughout most of October- March. Note the period of July- 847
August, when no hydrological events occurred, despite high rainfall rates, because 848
soils were dry and/or dried out quickly after rainfall. 849
Figure 3. Relationship between total event rainfall (mm) and total event discharge 850
(mm, normalised by field area) for events that occurred when a) soils were dry and 851
b) soils were near saturation, in all three intensively managed grassland fields. 852
Antecedent soil moisture conditions were defined as: dry soils when soil moisture 853
was at 10 cm <40%, 20 cm < 30%, 30 cm <36% and near saturation when soil 854
moisture levels were above these thresholds. A rainfall event of 40 mm total rainfall 855
occurring when antecedent soil conditions are dry is expected to have discharges of 856
approximately 10- 18 mm. The same rainfall event occurring when soils are wet is 857
likely to trigger 22- 30 mm of discharge. 858
Figure 4. Correlation between total event discharge and a) SS event yield (Field 2: 859
R2=0.81, Field 5: R2= 0.8, Field 8: R2= 0.82), b) TONN event yield (Field 2: R2=0.14, 860
Field 5: R2= 0.34, c) TP event yield (Field 2: R2=0.0.78, Field 5: R2= 0.8, Field 8: R2= 861
0.83), d) TC event yield (Field 2: R2=0.65, Field 5: R2= 0.49, Field 8: R2= 0.57), e) 862
correlation between SS event yield and TP event yield (Field 2: R2=0.77, Field 5: R2= 863
For Review Only
0.96, Field 8: R2= 0.99). Trendlines are only shown and R2 values given for 864
significant correlations. 865
866
Figure 5. Detailed description of one particular storm event which occurred on the 867
25-26/01/2013 in the three sampled intensively managed grassland fields: Field 2 868
start of the histological event at 16:45, lasting for 10.25 h, Field 5 start of the 869
hydrological event at 11:45, lasting for 15 h, Field 8 start at 16:15, lasting for 10.75h. 870
For each field, rainfall and hydrographs are presented as well as showing 871
hydrograph shape and chemograph/sedigraphs shapes (Field 2 a)-e), Field 5 f)-j), 872
Field 8 k)-o). Each parameter was measured at 15 minute time-steps, apart from TC, 873
for which manual samples are shown as individual dots. The x-axis shows hourly 874
ticks. 875
For Review Only
Table 1. Correlation functions between automated measurements and laboratory measurements (event-based samples taken in the same 15-minute slot). Note: the Nitratax was factory calibrated in Jan 2013, so the TONN calibration
functions are presented pre and post factory calibration. The two deployments of the Phosphaxes were: 1st deployment 14/12/2012-20/1202012, 2nd deployment 25/01/2013-12/02/2013.
TONN Nitratax-
TONN (pre factory
calibration)
TONN Nitratax-
TONN (post factory
calibration) TP Phosphax - TP (1st deployment) TP Phosphax - TP (2nd deployment) Turbidity NTU- SS Flume 2 y=1.07x-0.51 (R2=0.77 , N=12) y=0.53x+0.06 (R2=0.4, N=24) y=1.53x-0.04 (R2=0.89, N=16) y=1.29x-0.005 (R2=0.82, N=11) y=1.18x+0.05 (R2=0.75, N=256) Flume 5 y=0.62x-0.32 (R2=0.76 , N=17) y=0.53x+0.002 (R2=0.47, N=70) y=0.78x+0.03 (R2=0.69, N=16) y=0.91x+0.02 (R2=0.86, N=16) Flume 8 y=0.7x-0.01 (R2=0.7, N=17) y=0.83x-0.01 (R2=0.68, N=27) y=1.26x-0.02 (R2=0.72, N=19) y=1.08x-0.004 (R2=0.72, N=17) Table 2.
The water quality guidelines and their specific pollutant concentrations used to compare to the pollutant concentrations measured on the North Wyke Farm Platform. Note that guidelines were set for specific fractions of the pollutants measured in this study. No guideline for TC or specific fractions of C could be found.
Pollutant in this study
Guideline used Chemical guideline
set for
Guideline concentration
SS
EU Freshwater Fisheries Directive No specified SS
size 25 mg L
-1
lower SS standard than FFD used because FD was suggested to be too high (Bilotta et al., 2012, study on SS background levels of 638 UK water courses in reference state)
No specified SS
size 10 mg L
-1
TP
"good ecological status" (GES) specifically for the upper Taw catchment (UK Technical Advisory Group (TAG) standard devised for the EU Water Framework Directive)
dissolved molybdate reactive Phosphorus (MRP)
<0.04 mg L-1
"moderate ecological status" (MES) specifically for the upper Taw catchment (UK Technical Advisory Group (TAG) standard devised for the EU Water Framework Directive)
dissolved molybdate reactive Phosphorus (MRP)
<0.15 mg L-1
TONN EU Nitrates Directive NitrateN (NO3--N) <11.3 mg L-1
For Review Only
Table 3.
General overview of the three fields’ hydrological characteristics (mean, median, minimum and maximum) and number of events captured.
Field No. Total R Q total Q peak
Rainfall- runoff coefficient mm 1000L L s-1 % 2 Mean 15.9 517.2 28.1 46.2 Median 11.2 352.5 21.4 46.6 Minimum 2.4 70.4 6.9 12 Maximum 50 2124.4 97.6 82 N 61 61 61 61 5 Mean 14.2 586.7 37 63 Median 9.8 405.6 30.8 60.9 Minimum 2 52.5 6.8 9.9 Maximum 50.4 2424.9 105.8 132.7 N 64 64 64 64 8 Mean 15.8 701.3 38.5 54.3 Median 11 452.2 32.9 52.7 Minimum 3.2 87.7 8.6 12.7 Maximum 46.8 2583.6 103.9 128.7 N 59 59 59 59
For Review Only
37 Table 4.
General overview of the three fields' sediment ant macronutrient annual yields, event yields, and peak event concentrations. All measurements are normalised by field area. Where appropriate, mean median, minimum, maximum and number of captured events are shown.
Suspended Sediment (>1.2 µm) Total oxidized NitrogenN Total Phosphorus Total Carbon
Field annual yield † event yield peak event conc. annual yield † event yield peak event conc. annual yield ‡ event yield peak event conc. annual yield ‡ event yield peak event conc. kg ha-1 kg ha-1 mg L-1 ha-1 kg ha-1 g ha-1 mg L-1 ha-1 kg ha-1 g ha-1 mg L-1 ha-1 kg ha-1 kg ha-1 mg L-1 ha-1 2 Mean 191.3 3.5 19.9 1.7 11.9 0.2 0.42 7.4 0.16 122.2 2.2 4.5 Median 2.2 17.3 6 0.1 5.58 0.14 1.9 4.8 Min 182.2 0.3 6.6 1.4 0.2 0 0.88 0.04 0.5 2.2 Max 194.3 17.7 51.4 1.8 84.5 2 39.13 0.48 6.1 6.4 N 41 41 41 41 18 18 11 11 5 Mean 441.4 5.9 38 3 16.2 0.2 0.87 10.65 0.22 179.1 2.4 5.2 Median 4.3 29.3 11.5 0.2 8.1 0.23 2.4 5.3 Min 433.9 0.5 9.5 2.9 4.3 0.1 1.09 0.06 0.3 2.7 Max 527.4 25.5 109.2 3 70.1 0.3 49 0.37 7.1 6.9 N 30 30 42 42 18 18 12 12 8 Mean 218.1 3.7 17.8 1 10.8 0.1 0.44 7.14 0.18 109.4 1.9 3.2 Median 2.5 14.3 2.5 0 6.18 0.17 1.5 3.3 Min 213.4 0.4 5.1 0.9 0 0 0.55 0.03 0.4 1.1 Max 220.9 17.1 51.1 1 63.1 0.1 21.15 0.44 4.6 5.7 N 37 37 19 19 17 17 12 12
† Calculated with rating curves
For Review Only
Table 5. % of all SS, TP and TONN samples exceeding water quality guidelines in the discharge
water of three improved grassland fields. SS guideline: EU Freshwater Fisheries Directive and levels below this guideline, TP guideline: EU Water Framework Directive (note that the guidelines are set for soluble molybdate reactive Phosphorus SRP), guideline for TONN: EU Nitrates Directive (note that the guidelines are set for NO3
- -N). Field 2 Field 5 Field 8 SS > FFD (>25 mg SS L -1) 11.64 13.9 13.37 > 10 mg l-1 41.88 31.4 54.1 TP
fail "good ecological status" (>0.04 mg SRP L-1) 49.1 52.3 59.27 fail "moderate ecological status" (>0.15 mg SRP L1) 7.11 4.2 18.31 TONN
fail Nitrates Directive (>11.3 mg NO3 -