Information
Level 4 Data summaries and links to related documents and reports
Key findings
Annual rainfall over the six year period ranged from 384-932 mm with a median rainfall of 568 mm. Approximately 90% of rainfall events were less then 10 mm; these events produced less then 3% of total runoff at Glentulloch. Hence runoff was dominated by a small number of larger rainfall events. Rainfall events less then 10 mm would rarely affect antecedent moisture, and therefore runoff, as daily evaporation rates were usually greater then 10 mm.
Multiple regression analysis identified rainfall intensity, rainfall amount and ground cover as the three dominant parameters affecting event runoff and were able to account for 50-60 % of the variability in runoff at both sites. At low rainfall intensities (<20 mm/h) cover had little influence on runoff. For all rainfall intensities above 20 mm/h runoff decreased with increasing cover.
Soil loss ranged from 150 to 650 kg/ha/y in the exclosure and 500 to 2250 kg/ha/y for the medium and high utilisation rates. Soil loss with decreasing cover at Glentulloch was not as evident when compared to Kielambete.
Key tables and figures extracted from data, literature and miscellaneous publications