Identifying differences in the regionalisation of low flows and low flow salinity

摘要: Water resources in many parts of the world are experiencing degradation of the resource base and stress due to increasing demands. River diversions, clearing of native vegetation and irrigated agriculture can lead to salinisation of water and land resources and result in significant economic losses. The salinisation problem is a major threat to environmental sustainability. In order to better manage and control further degradation of limited water resources, predictions of water resource quantity as well as quality have to be improved.This study is motivated by salinisation of streams in response to landuse changes and aims to examine links between the regional behaviour of low flows and stream salinity. Stream salinity can be used as a hydrological response to catchment scale anthropogenic changes and a measure of stream water quality. It is observed that low flows have usually higher salt concentrations compared to high and medium streamflows. However, the question is how low flow salinity is associated with low flows, as the observed data on low flows and low flow salinity show great variability in space and time. This paper analyses the relationship between low flows and low flow salinity. In order to explain the spatial variability in low flows and low flow salinity in a sub-humid region, this study develops regional regression models, and identifies differences in the two regional models.