Defining the climatic signal in stream salinity trends using the Interdecadal Pacific Oscillation and its rate of change

V. H. Mcneil (1) , M. E. Cox (2)

1 Resource Sciences and Knowledge
2 School of Natural Resource Sciences

The impact of landuse on stream salinity is difficult to separate from decadal climatic variability, as the decadal scale climatic cycles in ground water and stream hydrology have similar wavelengths to the landuse pattern. These hydrological cycles determine the stream salinity through accumulation or release of salt in the landscape. The Interdecadal Pacific Oscillation (IPO) has been investigated before as an indicator of hydrological and related time series in the southern hemisphere. This study presents a new approach, which uses the rate of change in the IPO, rather than just its absolute value, to define an indicator for the climate component of ambient shallow groundwater tables and corresponding stream salinity. Representative time series of water table and stream salinity indicators are compiled, using an extensive but irregular database covering a very wide geographical area. These are modelled with respect to the IPO and its rate of change to derive climatic indicators. The effect of removing the decadal climatic influence from stream salinity trends is demonstrated.

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

V. H. Mcneil, M. E. Cox. Defining the climatic signal in stream salinity trends using the Interdecadal Pacific Oscillation and its rate of change. Hydrology and Earth System Sciences Discussions, 2006, 3 (5), pp.2963-2990. ⟨hal-00298775⟩