dataset: TEMP_50PC_SON_2030_A1B

Projection data is described in the gridcode column of the attribute table. This number is 1000 times the actual value (retained in this form to capture significant figures through map processing). For example, "Gridcode -23599" equates to -24% (rainfall) and "Gridcode 1986" equates to 2.0 degrees Celsius (temperature). The results are from 23 climate models that were available for the IPCC Fourth Assessment Report (2007). It is assumed that that the model results give a representation of the real world response to a specific emissions scenario. The IPCC (2007) estimates of global warming are relative to the period 1980-1999. For convenience, the baseline is often called 1990. Projections are given for 2030 and 2070 but, of course, individual years can vary markedly within any climate period, so the values can be taken as representative of the decade around the single year stated, i.e. projections for 2030 are representative of 2026-2035. Natural variability (independent of greenhouse gas forcing) can cause decadal means to vary and estimates of this effect are included in the estimates of uncertainties. The projections comprise a central estimate and a range of uncertainty. The central estimate is the median – or 50th percentile - of the model results, while the uncertainty range is based on two extreme values – the 10th and 90th percentiles. 10% of values fall below the 10th percentile and 10% of values lie above the 90th percentile. Greater emphasis is given to projections from models that best simulate the present climate. The weightings are based on statistical measures of how well each model can simulate the 1975-2004 average patterns of rainfall, temperature, and sea level pressure over Australia. Subregions of Victoria are indicated. Victoria has an integrated catchment management system established under the Catchment and Land Protection Act 1994 (the CaLP Act). Under the CaLP Act, Victoria is divided into ten catchment regions, with a Catchment Management Authority (CMA) established for each region. (See: http://www.water.vic.gov.au/governance/catchment_management_authorities)