1. Source Catchments
Paddock to Reef integrated Monitoring and
Modelling Program
Dr Gillian McCloskey
DERM Senior
Catchment Modeller

2. Reef WQ Targets
By 2013, at the end of catchment there will be a
minimum:
50% Reduction in Nitrogen & Phosphorus
50% Reduction in pesticides, and
50% late dry season groundcover on dry tropical grazing land
By 2020, at the end of catchment there will be a minimum
20% reduction in sediment loads

3. Banti Fentie
Rob Ellis
Cameron Dougall
Louise Hateley
Gill McCloskey
Helle Vittinghus

4. Model Key Objectives
To assess and report on
progress towards meeting
Reef Water Quality targets
Simulate and quantify
impact of current and
improved management
practises on stream
constituents, loads and
water quality in the GBR
catchments
Modelled load estimates for:
• Pre-European
• Baseline 2008 -2009
• Annual report cards for 3 yrs

5. Region Size Climate Rainfall Dominant Land
Km2 Zone (mm/yr) use
Cape York 42,793 Tropical 800 - Grazing 52%
2400 Nature
Conservation 46%
Wet Tropics 22,000 Tropical 716 – Grazing 46 %
3015 Nature
conservation 33 %
Sugar 9 %
Burdekin 138,245 Dry 649 - Grazing 94 %
tropics 1800 Forest and Nature
Conservation 2.5 %
Sugar cane 1 %
Mackay 9021 Dry 600 - Grazing 47 %
/ tropics 3000 Forest and Nature
Whitsundays Conservation 26 %
Sugar 19 %
Fitzroy 142,000 Dry 526 - Grazing 82 %
tropics/ 2065 Forest and Nature
Sub Conservation 9.4 %
tropics Cropping 6.7 %
Burnett/ 51,722 Sub 600-2000 Grazing 78%
Mary tropics Forest 15.5 %
Cropping 4.3 %
Total modelled Area = 361488 km2

6. Model Setup in Source Catchments
Whole GBR catchment needs to be comparable
and as close to real life as possible
– Loads quantifiable – one number
– Same scale and time step: sub catchments and daily
– Functional units: 9 standard, up to 3 regional FU’s
– Storages, Extractions and Inflow as per DERM Water Planning
– Same rules for gauge inclusion; Quality codes and time series

7. Model Setup
Whole GBR Catchment and
each region
• 1 Outlet: All sub catchment with GBR
outlet runs through one outlet node
• Landuse in to 11 Functional units
• Storages added as Link models,
Storage-demand added as node
models on the node immediately
downstream
• Water extractions added as node
models
• Gauges used for calibration from 1970
– 2010, sorted by min 10 years data,
not downstream of a storage

8. Source Catchment Components
Region Number of Sub Size of Sub Number of nodes/ Storages Extractions after
catchment catchment in km2 links IQQM
Cape York 545 50 546/545 - -
Wet Tropics 450 30 451/450 2 2
Burdekin 1564 50 1565/1564 5 10
Mackay 191 30 192/191 9 5/2
/
Whitsundays
Fitzroy 1600 50 1601/1600 ? ?/?
Burnett/ 597 50 598/597 14 22
Mary

10. Hydrology Calibration - PEST
PEST – Parameter Estimation Tool
GBR Models – size, number of FU’s
Each FU has a RR model, & each RR model has many
parameters (SimHyd – 9)
CYP example – 545 subcatchments, 10 FU’s, 7 adjustable
SimHyd params, 2 routing parameters = 49050
Too many parameters! Will affect computing power.

11. Hydrology Calibration - PEST
Condense number of FU’s
(no. of FU’s x no. of regions x 7 adjustable SimHyd params) + (no. of
regions x 2 flow routing params) = 414 parameters (in Cape York)
Objectives: Daily Nash-Sutcliffe of 0.5, Monthly NS of 0.8 and modelled
vs measured flows within 10-20%
Initial approach – regionalisation
regions based on areas with similar rainfall, soil type & geology
etc
Next approach – one region per gauge

12. • 14 gauges (all three objective functions met)
• 3 gauges (two objective functions met)
• 1 gauge (one objective function met)

14. Parameterisation 1 Parameterisation 2 Parameterisation 3 Parameterisation 4 Parameterisation 5

15. Hydrology Calibration - PEST

16. End of system
Barron River
110001A

17. Picnic Crossing
head waters of
the Barron
110003A

18. Flaggy Creek
Rainforest
110011B

19. Where we are at
Dynamic SedNet testing: in progress
Incorporation of paddock scale modelling
outputs
Report due: 30 May. This year.
(Dave: how many days is that?)

20. Whats next future