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Global warming has had significant effects on the hydrological cycle. In North Africa, these effects have resulted in a continued decrease in the amount of annual precipitation, greatly influencing the availability of surface and groundwater resources. This paper aims to evaluate drought episodes in a long dataset from Djelfa (Algeria) using a statistical approach based on a decision support system enabled by the Hyfran-plus software, to fit the best statistical distribution model and predict non-exceedance probability of precipitation. The standardized precipitation index is used to highlight sequences of meteorological drought and changes in weather patterns. Shift in precipitation has been identified by Wilcoxon Test for homogeneity; Wold-Wolfowitz test of independence, Kendall's test of trend and new cumulative mean difference curve (CMD) developed to visualize the trend of the precipitation and runoff dataset, Autocorrelation function (ACF) and Fourier spectrum and Deuterium excess isotopes has been used to visualize trends. Log–log plot; the mean excess function (MEF), AIC and BIC criteria are used to select the best distribution fitting model. The statistical results obtained indicate that the dataset follows a heavy-tailed distribution (Pearson type III), Values of excess Deuterium indicate that groundwater recharge has occurred in cold weather different from the actual period. SPI analysis shows that dry years cover more than 51% compared to 49% of wet years. The CMD curve shows a change and trend in the precipitation and runoff time series since 1974. Forecasts show drought recurrences to be between 3 and 200 years. [ABSTRACT FROM AUTHOR]

The average annual precipitation values in the Cheliff-Zahrez basin range from 80 to 600 mm/an, indicating a semi-arid climate. This work revolves around a new drought exceedance probability index (DEPI), a standardized precipitation index (SPI) and effective drought index (EDI) in different time scales (3, 6, 9, 12 and 24) derived from monthly precipitation series stretching from September 1970 to August 2015. The latter aims to analyze the performance, similarities and differences between the most used drought indices such as SPI and EDI and to compare their results with those obtained using DEPI. The results indicated that the majority of selected stations tend to a decline in annual rainfall, with a dominant break in series between 1970 and 1980. The Mann–Kendall test result showed that the monthly rainfall trend had significantly decreased in the majority of studied stations. Furthermore, the SPI and EDI series showed persistent monthly drought conditions from January 1970 to March 2010 with an extreme drought peak of − 3. However, the DEPI index showed monthly drought events (< 0.5) of different classes beginning from March 1980 to December 2010. In the study area, the coefficient of determination explained a high variation (> 80%) between SPI and EDI at the time scale of 24 months. At the 9- and 12-month scale, the coefficient of determination showed a variance greater than 50% over the entire basin. On the other hand, the coefficients of determination results between SPI and EDI for the time scale of 3 to 6 months are characterized by a gradient from the northeast to southwest or from 10 to 90%. The stations of the Coastline 2 basin have revealed that the relationship between SPI and DEPI as well as EDI and DEPI is not significant, being allowed between 10 and 30% on time scales of 3, 6, 9, 12 and 24 months. The results of this work and information on the severity and persistence of droughts will be essential to enable managers to adopt an integrated and sustainable management of scarce resources and aim at minimizing agricultural production losses in the region. [ABSTRACT FROM AUTHOR]

The design of hydraulic infrastructure requires careful evaluation of extreme precipitation events. This paper presents an estimation of extreme precipitation events based on the Probable Maximum Precipitation (PMP) concept. The PMP approach is useful in determining probable maximum flood (PMF), which is required for the design of large hydraulic structures. Therefore, in this study, 24-h PMP estimates were performed through 43 rainfall stations located in the Cheliff watershed in Algeria. This estimation was implemented based on moisture maximization and Hershfield statistical method. The 24-h PMP values vary between 109.2 and 741.6 mm for the first approach and between 151.5 and 369.4 mm for the second approach. Using the moisture maximization approach, the 24-h PMP values obtained are approximately double those based on the Hershfield statistical method, with return periods ranging from 1000 to 28 106 years for the majority of stations in the Cheliff basin. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Drought assessment and characterization using SPI, EDI and DEPI indices in northern Algeria" published in the journal Natural Hazards. The correction states that the given and family names of the authors were shuffled incorrectly in the original version of the article. The correction has been made to the original article. The publisher, Springer Nature, remains neutral in terms of jurisdictional claims and institutional affiliations. The authors of the article are Brahim Habibi, Mohamed Meddi, Topçu Emre, Abdelkader Boucefiane, and Abedelwahab Rahmouni. [Extracted from the article]

The rapid demographic evolution wields a big pressure on water resources potentialities; in addition, the climate change effects have influenced the natural renovation rate of water resources around the world. Starting from a previous published model, a sensitive analysis was established after introducing three parameters as watershed topography, stream network density and geology index to illustrate the impact of each of these parameters on the rate of groundwater recharge. This modified model has been improved by in-site experiment (soil chloride mass balance) tested in some selected sites in Sidi Slimane River located in the region of Djelfa at 300 km from Algiers (Algeria). The results obtained show that the parameters like geology, topography and the amount of rainfall and the drainage density influence the velocity of groundwater recharge. By introducing the chloride concentration in soil, the model becomes most independent and gives good results that can be used in water resources planning in semiarid land. [ABSTRACT FROM AUTHOR]