The use of hybrid methods for change points and trends detection in rainfall series of northern Algeria

A new regionalization of rainfall patterns based on wavelet transform information and hierarchical cluster analysis in northeastern Algeria

“…12) of the three groups resulting from the cluster method shows exceptionally rainy years exceeding the significance level between 1972-1974, 1980-1984, and 2002-2006. In contrast, dry periods are marked by low variability, below the significance level, between 1974-1980 and 1984-2002. This period of drought is well-established, particularly in the region including G2 (Fig. 12c, d); it has also been observed in the Mediterranean basin (Zerouali et al, 2020;Khezazna, et al, 2017;Philandras et al, 2011;Piccarreta et al, 2013;Nouaceur and Murărescu, 2016). According to Hasanean (2004), the negative trends of rainfall in the western Mediterranean coincide with subtropical anticyclonic trends, which, since 1970, have been known to increase pressure.…”

“…Understanding climate variability, climate change and global warming is essential for understanding world's water cycle. Understanding the various components water cycle's components has been the aim of a large body of studies on rainfall, flow, temperature, evaporation, infiltration (Mengistu et al, 2021;Dang et al, 2021;Pokharel et al, 2020;Nistor et al, 2020;Li et al, 2020;Bouabdelli et al, 2020;Zerouali et al, 2020;Machiwal et al, 2019;Pathak et al, 2017;Santos et al, 2018;Gocic and Trajkovic 2014;Duncan et al, 2013;Meddi et al, 2010) to be the key elements in designing and managing civil engineering structures, particularly studies on the precipitation component (Wolski et al, 2021;Martinez-Artigas et al, 2020;Zerouali et al, 2021;Machiwal et al, 2019;Lazri 3 and Ameur, 2018;Teodoro et al, 2015;Conway et al, 2010;Massei et al, 2011). Studies on rainfall are the most common compared to the other components; thus, the results of these works can help managers in decision-making processes in the field of water resources.…”

“…Using copula analysis on data from 194 rain gauges located in northern Algeria for drought event identification, the severity-area-frequency and severity-duration-frequency curves indicated that the western part of the region is the most sensitive to dangerous and severe droughts of short durations and high probabilities of exceedance (Mellak and Souag-Gamane 2020). Based on rain gauges in northern Algeria, Zerouali et al (2020) used relatively new hybrid methods for the detection of changes points and trends during the period from 1920-2011. The results revealed a decline in the rainfall amount beginning in the 1970s in the western part of the region.…”

“…In contrast, humid and subhumid climate regions will be dominated by seasonal, annual and interannual fluctuations that explain shortto medium-term processes. Based on long-term and quality-controlled rainfall time series in southwestern Europe (Peña-Angulo et al, 2020) and northern Algeria (Zerouali et al, 2020), the authors of previous studies found that in the absence of statistically significant long-term trends (increasing/decreasing) in rainfall time series, except for over short periods, the interannual to interdecadal mode of variability detected in the analyses can contribute to hiding longterm trends in rainfall time series. This finding is important for the detection of change points and trends in studies of hydrology and earth science.…”

A new regionalization of rainfall patterns based on wavelet transform information and hierarchical cluster analysis in northeastern Algeria

“…Understanding climate variability, climate change and global warming is essential for understanding world's water cycle. Understanding the various components water cycle's components has been the aim of a large body of studies on rainfall, flow, temperature, evaporation, infiltration (Mengistu et al, 2021;Dang et al, 2021;Pokharel et al, 2020;Nistor et al, 2020;Li et al, 2020;Bouabdelli et al, 2020;Zerouali et al, 2020;Machiwal et al, 2019;Pathak et al, 2017;Santos et al, 2018;Gocic and Trajkovic 2014;Duncan et al, 2013;Meddi et al, 2010) to be the key elements in designing and managing civil engineering structures, particularly studies on the precipitation component (Wolski et al, 2021;Martinez-Artigas et al, 2020;Zerouali et al, 2021;Machiwal et al, 2019;Lazri and Ameur, 2018;Teodoro et al, 2015;Conway et al, 2010;Massei et al, 2011). Studies on rainfall are the most common compared to the other components; thus, the results of these works can help managers in decision-making processes in the field of water resources.…”