Streamflow decline in southwestern Australia, 1950–2008

摘要: [1] Southwest Western Australia (SWWA) has experienced a 15–20% reduction in rainfall since the 1970s with severe reductions inflows to Perth drinking water reservoirs. To quantify and runoff patterns, we used trend change point analyses for 50 year record (1950–2008) last two decades (1989–2008). From 1950–2008, tests showed significant declines annual corresponding points both flow late 1960s or mid-1970s. In more recent (1989–2008), declined majority of catchments, but did not show downward trend. Rather, streamflow decline was observed as step response occurrence below-average years. A shift from perennial ephemeral streams coefficient (runoff/rainfall) decade suggests new hydrologic regime developed important implications future surface supply.