An Enhanced Innovative Triangular Trend Analysis of Rainfall Based on a Spectral Approach

The world is currently witnessing high rainfall variability at the spatiotemporal level. In this paper, data from three representative rain gauges in northern Algeria, 1920 to 2011, an annual scale, were used assess a relatively new hybrid method, which combines innovative triangular trend analysis (ITTA) with orthogonal discrete wavelet transform (DWT) for partial identification. revealed that period 1950 1975 transported wettest periods, followed by long-term dry beginning 1973. also increase during latter decade. combined method (ITTA–DWT) showed good efficiency extreme event detection. addition, indicated inter- multiannual phenomena explained short medium processes dominated variability, masking components existing time series and making identification of such trends challenging task. results indicate approaches—combining ITTA selected input combination models resulting DWT—are auspicious compared those found using original observations. This ITTA–DWT outperformed identification, proved DWT’s as coupling method.