41.1 Precipitation on storages
The volume reported (10,700 ML) represents the total precipitation falling onto surface water storages within the Adelaide region during the 2010–11 year. Precipitation to each surface water storage during the 2010–11 year is provided in the following table.
|Surface water storages||Volume (ML)
|Mount Bold Reservoir||2,177|
|Kangaroo Creek Reservoir||667|
|Little Para Reservoir||592|
|South Para Reservoir||3,170|
Monthly precipitation data were produced by the Bureau of Meteorology. These were based on daily data from approximately 6,500 rain gauge stations and interpolated to a 0.05 degree (approximately 5 km) national grid (Jones et al. 2007)
Precipitation at each waterbody was estimated from the proportionally weighted average of grid-point cells that intersected each storage or weir (water feature). The precipitation volume was then estimated using the surface area of each waterbody. Surface area varied dynamically with changing storage level for storages, where the relationship between storage level and surface area has been derived.
Assumptions, Limitations, Caveats and Approximations
- The precipitation estimates were subject to approximations associated with interpolating observation point data to a national grid 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.
- Precipitation was only estimated for the surface water storages and weirs (for which data were available) within the Adelaide region and did not include river channels.
The uncertainty estimate was not quantified.