• Catchment Management
• Project Background
• Monitoring
• Soil Descriptions
• Vegetation Descriptions
• Topography
• Allt a' Mharcaidh references
• Deposition Chemistry
  • Bulk deposition chemistry
  • Interception deposition chemistry
• Snow
• Vegetation community composition
• Soil characteristics and chemistry
• Ground water chemistry
• Surface water chemistry
• Automatic Weather Station (CEH)
• Current Research Project
• Management of the Reserve

Allt a' Mharcaidh Catchment

Interception Deposition Chemistry

The quality and quantity of interception deposition is monitored at the site using ground level gauges with a column of interception mesh that is positioned on top of the gauge to collect mist and fog. Although both wet and dry deposition is collected by the interception gauge, it is generally accepted that in areas such as the Allt a’ Mharcaidh catchment, remote from emission sources, the dry deposition component of acid deposition is minimal. The location of the interception gauges represents differences in altitude, topography and aspect.

In 1990, the original experimental design was modified to account for an area of the catchment that was exposed, north facing and with no instrumentation.  Filter gauges (FG2, 3 and 7) for monitoring interception deposition were positioned adjacent to three of the bulk deposition collectors (RG 2, 3 and 7). Following the completion of the deposition study in 1997 (monitoring at FG2 continued until 1998), all filter gauges at sites 2, 3 and 7 were removed.

To access the data charts click on interactive chart or use the list below:

• Filter Gauge 2
• Filter Gauge 3
• Filter Gauge 7

Analytical data were rejected from the study when there was evidence of contamination from birds (i.e. phosphate concentrations >0.5 mgl^-1, potassium >0.2 mgl^-1, nitrogen species >0.5 mgl^-1). No observation was rejected as long as the sum base cations (Mg, Na, K, Ca, H, NH₄-N) / sum of acid anions (SO₄-S, NO₃-N, Cl) was within a ± 10 % error for that individual sample