Table 11 . Summary of monitoring outcomes for the 2017-18 , 2018-19 , 2019-20 and 2020-21 wet seasons at the Mt Wickham treatment and control sites . Note that the confidence in the loads data is rated as ‘ Fair ’. Source : Derived from Bartley et al . ( 2019 , 2020 and 2021 ).
Mt Wickham 2017-18 ( Baseline ) 2018-19 2019-20 2020-21
Treatment Control Treatment Control Treatment Control Treatment Control Site Rainfall ( mm ) 1 127 152 1,117 1,175 370 390 638 655 Hillslope (% cover ) 83 73 89 50 91 % 34 % Gully walls (% cover ) 35 29 79 29 65 % 30 % Gully floor (% cover ) 35 29 42 3 62 % 9 %
Flow weighted annual average TSS concentration ( mg / L ) 2
30,243 56,163 15,868 32,491 5,118 49,356 2670 26871
Total TSS loss ( t / y ) 7.3 2.81 170.8 159.2 1.2 1.7 0.5 1.3 TSS yield ( t / ha ) 0.52 0.9 12.1 52.5 0.09 0.56 0.04 0.43
Flow weighted annual average TN concentration ( ug / L ) 2
9,303 11,156 6,162 5,384 5,118 49,356 2391 5949
Total TN loss ( kg / y ) 2.3 0.5 66.3 26.4 1.2 1.7 0.5 0.3 TN yield ( kg / ha ) 0.2 0.2 4.7 8.7 0.09 0.56 < 0.1 0.1
Note : Catchment area ( ha ) above the monitoring stations is 14.1ha for the treatment and 3.0ha for the control , measured using LiDAR .
1
Long term rainfall is 626 mm ( BOM 2000 – 2018 ), and the 2017-18 Baseline year only represented Feb-July rainfall in 2018 as the equipment was only installed in Feb 2018
2
Confidence in the discharge and loads data is ‘ Fair ’.
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