Perth
9.1 Precipitation on surface water
Supporting information
The volume reported in the water accounting statements (20,317 ML) represents the volume of precipitation that fell on the major surface water storages within the Perth region during the 2012–13 year.
The total volume of rainfall on each storage during the 2012–13 year within the Perth region is provided in the following table.
Storage |
Rainfall (ML) |
Canning |
1,389 |
Churchman Brook |
139 |
Drakes Brook |
317 |
Harvey |
2,986 |
Logue Brook |
528 |
Mundaring |
2,339 |
North Dandalup |
1,615 |
Samson Brook |
237 |
Serpentine |
2,990 |
Serpentine Pipehead |
452 |
South Dandalup |
2,567 |
Stirling |
2,233 |
Victoria |
312 |
Waroona |
575 |
Wungong |
1,638 |
Total |
20,317 |
Quantification approach
Data source
Provided by
Method
Monthly precipitation grids were produced using daily data from approximately 6,500 rain gauge stations and interpolated to a 0.05 degree (5 km) national grid (Jones et al. 2007).
The precipitation on each waterbody was estimated from the proportionally weighted average of grid-cells that intersected each water feature. The volume was then estimated using the surface area of each waterbody. The average monthly surface area of the major storages was calculated from daily storage levels and capacity tables.
The surface area of all the storages in the Perth region was calculated using this dynamic method.Assumptions, limitations, caveats and approximations
The precipitation estimates were subject to approximations associated with interpolating the observation point data to a national grid as detailed in Jones et al. (2007).
The dynamic storage surface areas calculated from the levels and capacity tables represent a monthly average and therefore will not capture changes that occur on a shorter temporal scale.
The total surface area of the surface water store within the Perth region included only the storages (and not the rivers).