Influence of forestry, environmental change and climatic variability on the hydrology, hydrochemistry and residence times of upland catchments

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Abstract

Long-term (>25 year) hydrological and hydrochemical data sets for two small afforested catchments at Loch Ard, Central Scotland, are analysed to assess the effects of forest management, environmental change and climatic variability. The two catchments, B10 (0.9 km(2)) and B11 (1.4 km(2)) are dominated by acidic gley soils. Their streams have responsive hydrological regimes and acidic surface waters with pH ranging from similar to 5.5 at low flows to 4.0 at high flows. Partial clear-felling appeared to have limited effects on the catchment water balances, though flood peaks and low flows might be enhanced for short periods of a few years. Felling had a notable, short-term, perturbation on stream water chemistry, with both NO3 and K concentrations being increased. Stream chemistry also exhibited marked variability in response to climatic conditions and changing atmospheric inputs, which resulted in strong inter-annual and seasonal variation of precipitation quantity and quality. These influence annual stream flows and chemistry, with marine-derived Cl and Na being the dominant anion and cation. Emission controls of acidic oxides from fossil fuel burning have reduced SO4 concentrations in precipitation; a trend that has been exacerbated by felling and mirrored in the two streams. This has corresponded to declining levels of inorganic aluminium. In contrast, dissolved organic carbon concentrations have increased possibly in response to warmer drier summers and felling operations. Chemically-based hydrograph separations indicated that groundwater comprised 25-35% of annual runoff in both catchments, with no evidence of any change relating to forest management. Cl data were used to estimate mean catchment residence times by applying lumped parameter models. Both catchments have mean residence times on the order of a few months, though they are about 1 month shorter in B10 which is consistent with differences in soils and topography, though this might also reflect differences in forest management.

Original languageEnglish
Pages (from-to)93-111
Number of pages19
JournalJournal of Hydrology
Volume346
Issue number3-4
Early online date29 Aug 2007
DOIs
Publication statusPublished - 30 Nov 2007

Keywords

  • climatic change
  • forestry
  • runoff generation
  • long-term trends
  • water quality
  • mean residence times
  • stream-water-quality
  • nested mesoscale catchment
  • stable-isotope tracers
  • mid-Wales
  • surface-water
  • hydrograph separation
  • contaminant transport
  • afforested catchment
  • central Scotland
  • runoff processes

Cite this

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title = "Influence of forestry, environmental change and climatic variability on the hydrology, hydrochemistry and residence times of upland catchments",
abstract = "Long-term (>25 year) hydrological and hydrochemical data sets for two small afforested catchments at Loch Ard, Central Scotland, are analysed to assess the effects of forest management, environmental change and climatic variability. The two catchments, B10 (0.9 km(2)) and B11 (1.4 km(2)) are dominated by acidic gley soils. Their streams have responsive hydrological regimes and acidic surface waters with pH ranging from similar to 5.5 at low flows to 4.0 at high flows. Partial clear-felling appeared to have limited effects on the catchment water balances, though flood peaks and low flows might be enhanced for short periods of a few years. Felling had a notable, short-term, perturbation on stream water chemistry, with both NO3 and K concentrations being increased. Stream chemistry also exhibited marked variability in response to climatic conditions and changing atmospheric inputs, which resulted in strong inter-annual and seasonal variation of precipitation quantity and quality. These influence annual stream flows and chemistry, with marine-derived Cl and Na being the dominant anion and cation. Emission controls of acidic oxides from fossil fuel burning have reduced SO4 concentrations in precipitation; a trend that has been exacerbated by felling and mirrored in the two streams. This has corresponded to declining levels of inorganic aluminium. In contrast, dissolved organic carbon concentrations have increased possibly in response to warmer drier summers and felling operations. Chemically-based hydrograph separations indicated that groundwater comprised 25-35{\%} of annual runoff in both catchments, with no evidence of any change relating to forest management. Cl data were used to estimate mean catchment residence times by applying lumped parameter models. Both catchments have mean residence times on the order of a few months, though they are about 1 month shorter in B10 which is consistent with differences in soils and topography, though this might also reflect differences in forest management.",
keywords = "climatic change, forestry, runoff generation, long-term trends, water quality, mean residence times, stream-water-quality, nested mesoscale catchment, stable-isotope tracers, mid-Wales, surface-water, hydrograph separation, contaminant transport, afforested catchment, central Scotland, runoff processes",
author = "Doerthe Tetzlaff and Malcolm, {I. A.} and Christopher Soulsby",
year = "2007",
month = "11",
day = "30",
doi = "10.1016/j.jhydrol.2007.08.016",
language = "English",
volume = "346",
pages = "93--111",
journal = "Journal of Hydrology",
issn = "0022-1694",
publisher = "Elsevier Science B. V.",
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TY - JOUR

T1 - Influence of forestry, environmental change and climatic variability on the hydrology, hydrochemistry and residence times of upland catchments

AU - Tetzlaff, Doerthe

AU - Malcolm, I. A.

AU - Soulsby, Christopher

PY - 2007/11/30

Y1 - 2007/11/30

N2 - Long-term (>25 year) hydrological and hydrochemical data sets for two small afforested catchments at Loch Ard, Central Scotland, are analysed to assess the effects of forest management, environmental change and climatic variability. The two catchments, B10 (0.9 km(2)) and B11 (1.4 km(2)) are dominated by acidic gley soils. Their streams have responsive hydrological regimes and acidic surface waters with pH ranging from similar to 5.5 at low flows to 4.0 at high flows. Partial clear-felling appeared to have limited effects on the catchment water balances, though flood peaks and low flows might be enhanced for short periods of a few years. Felling had a notable, short-term, perturbation on stream water chemistry, with both NO3 and K concentrations being increased. Stream chemistry also exhibited marked variability in response to climatic conditions and changing atmospheric inputs, which resulted in strong inter-annual and seasonal variation of precipitation quantity and quality. These influence annual stream flows and chemistry, with marine-derived Cl and Na being the dominant anion and cation. Emission controls of acidic oxides from fossil fuel burning have reduced SO4 concentrations in precipitation; a trend that has been exacerbated by felling and mirrored in the two streams. This has corresponded to declining levels of inorganic aluminium. In contrast, dissolved organic carbon concentrations have increased possibly in response to warmer drier summers and felling operations. Chemically-based hydrograph separations indicated that groundwater comprised 25-35% of annual runoff in both catchments, with no evidence of any change relating to forest management. Cl data were used to estimate mean catchment residence times by applying lumped parameter models. Both catchments have mean residence times on the order of a few months, though they are about 1 month shorter in B10 which is consistent with differences in soils and topography, though this might also reflect differences in forest management.

AB - Long-term (>25 year) hydrological and hydrochemical data sets for two small afforested catchments at Loch Ard, Central Scotland, are analysed to assess the effects of forest management, environmental change and climatic variability. The two catchments, B10 (0.9 km(2)) and B11 (1.4 km(2)) are dominated by acidic gley soils. Their streams have responsive hydrological regimes and acidic surface waters with pH ranging from similar to 5.5 at low flows to 4.0 at high flows. Partial clear-felling appeared to have limited effects on the catchment water balances, though flood peaks and low flows might be enhanced for short periods of a few years. Felling had a notable, short-term, perturbation on stream water chemistry, with both NO3 and K concentrations being increased. Stream chemistry also exhibited marked variability in response to climatic conditions and changing atmospheric inputs, which resulted in strong inter-annual and seasonal variation of precipitation quantity and quality. These influence annual stream flows and chemistry, with marine-derived Cl and Na being the dominant anion and cation. Emission controls of acidic oxides from fossil fuel burning have reduced SO4 concentrations in precipitation; a trend that has been exacerbated by felling and mirrored in the two streams. This has corresponded to declining levels of inorganic aluminium. In contrast, dissolved organic carbon concentrations have increased possibly in response to warmer drier summers and felling operations. Chemically-based hydrograph separations indicated that groundwater comprised 25-35% of annual runoff in both catchments, with no evidence of any change relating to forest management. Cl data were used to estimate mean catchment residence times by applying lumped parameter models. Both catchments have mean residence times on the order of a few months, though they are about 1 month shorter in B10 which is consistent with differences in soils and topography, though this might also reflect differences in forest management.

KW - climatic change

KW - forestry

KW - runoff generation

KW - long-term trends

KW - water quality

KW - mean residence times

KW - stream-water-quality

KW - nested mesoscale catchment

KW - stable-isotope tracers

KW - mid-Wales

KW - surface-water

KW - hydrograph separation

KW - contaminant transport

KW - afforested catchment

KW - central Scotland

KW - runoff processes

U2 - 10.1016/j.jhydrol.2007.08.016

DO - 10.1016/j.jhydrol.2007.08.016

M3 - Article

VL - 346

SP - 93

EP - 111

JO - Journal of Hydrology

JF - Journal of Hydrology

SN - 0022-1694

IS - 3-4

ER -