A drought index based on river flows
Roddy Henderson, NIWA
Catchment Proccesses and Water Resources
Figure 1: River flows for the Selwyn River in Canterbury, representative of the South Island east coast. The RDI reached a peak of almost 6 at the start of 1999, highlighting the major drought of 1998–99 and its relative severity.
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Figure 2: Flows from Lake Wanaka between 1970 and 2002, representative of flows through the major South Island hydro-electric stations.