Controls on Catchment-Scale Patterns of Phosphorus in Soil, Streambed Sediment, and Stream Water
- Marcel van der Perk *a,
- Philip N. Owensb,
- Lynda K. Deeksb,
- Barry G. Rawlinsc,
- Philip M. Haygarthd and
- Keith J. Bevene
- a Dep. of Physical Geography, Utrecht Univ., P.O. Box 80 115, 3508 TC Utrecht, The Netherlands
b National Soil Resources Inst., Cranfield Univ., North Wyke Research Station, Okehampton, Devon EX20 2SB, UK
c British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
d Cross Institute Programme for Sustainable Soil Function, Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon EX20 2SB, UK
e Dep. of Environmental Science, Lancaster Univ., Lancaster, LA1 4YQ, UK
Many models of phosphorus (P) transfer at the catchment scale rely on input from generic databases including, amongst others, soil and land use maps. Spatially detailed geochemical data sets have the potential to improve the accuracy of the input parameters of catchment-scale nutrient transfer models. Furthermore, they enable the assessment of the utility of available, generic spatial data sets for the modeling and prediction of soil nutrient status and nutrient transfer at the catchment scale. This study aims to quantify the unique and joint contribution of soil and sediment properties, land cover, and point-source emissions to the spatial variation of P concentrations in soil, streambed sediments, and stream water at the scale of a medium-sized catchment. Soil parent material and soil chemical properties were identified as major factors controlling the catchment-scale spatial variation in soil total P and Olsen P concentrations. Soil type and land cover as derived from the generic spatial database explain 33.7% of the variation in soil total P concentrations and 17.4% of the variation in Olsen P concentrations. Streambed P concentrations are principally related to the major element concentrations in streambed sediment and P delivery from the hillslopes due to sediment erosion. During base flow conditions, the total phosphorus (<0.45 μm) concentrations in stream water are mainly controlled by the concentrations of P and the major elements in the streambed sediment.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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