Susza i gromadzenie wód powierzchniowych w obszarach półsuchych. Przykład zapory wodnej Hammam Boughrara (w północno-zachodniej Algierii)

The dam of Hammam Boughrara is an embankment dam built in a transboundary basin, between Algeria and Morocco; it was type-approved and delivered in 1998. This dam was supposed to solve the lack of drinking water in Oran (Algeria's second largest city) and enhance the agricultural perimeter of the area. It should regulate an annual water volume of 59 million m3. However, the northwest Algeria has experienced a fairly severe drought since the 80s. This article aims to show the impact of this drought on the amount of surface water that can be mobilized by this dam. The rainfall series recorded at four stations, located within the basin of the dam, were examined using the proportional deviation from the average, the running average, the frequency analysis, the Pita’s index and the standardized precipitation index. These methods have shown a significant decrease of rain, starting from the hydrological year 1975/1976. These same approaches were also used to analyse series of flows spread over a longer period. This fact revealed three periods of drought which are 1940–1945, 1955–1967 and the most recent one highlighted by the rainfall series, starts at the year 1975/1976. The regularized water volume of the dam, calculated from the series of flow rates, is around 37 million m3. This value reflects a deficit of 40% of the regularized volume predicted by the designers of the dam.Zaporę Hammam Boughrara zbudowano na granicy Algierii i Maroka i uruchomiono w 1998 r. Zapora miała na celu rozwiązać problem braku wody pitnej w Oranie (drugim co do wielkości mieście Algierii) i zwiększyć zasięg rolnictwa w regionie. Miała regulować rocznie zasoby wody o objętości 59 milionów m3. Północnozachodnie regiony Algierii doświadczają jednak silnej suszy od lat osiemdziesiątych XX wieku. Artykuł ma wykazać wpływ tej suszy na ilość wody, którą może gromadzić zbiornik. Serie opadowe notowane w czterech stacjach zlokalizowanych w zlewni zbiornika analizowano z wykorzystaniem proporcjonalnego odchylenia od średniej, ruchomej średniej, analizy częstości, wskaźnika Pity i wskaźnika standaryzowanego opadu. Stosowane metody wykazały istotne zmniejszenie ilości opadu począwszy od roku hydrologicznego 1975/1976. Takie samo podejście zastosowano do analizy serii szybkości przepływu, które obejmują dłuższy okres. Analiza ujawniła trzy okresy suszy, które przypadały na lata 1940–1945, 1955–1967 i ostatni wykazany przez serie opadów, który rozpoczął się w roku 1975/1976. Zasoby wody regulowane rocznie obliczone z serii przepływów wynoszą ok. 37 milionów m3. Ta ilość w istocie odzwierciedla deficyt gromadzonej wody, gdyż jest o 40% mniejsza niż objętość przewidywana przez projektantów zapory

Genetic Diversity and Differentiation of Eleven Medicago Species from Campania Region Revealed by Nuclear and Chloroplast Microsatellites Markers

The species belonging to the genus Medicago are considered a very important genetic resource at global level both for planet’s food security and for sustainable rangelands management. The checklist of the Italian flora (2021) includes a total number of 40 Medicago species for Italy, and 27 for Campania region, with a number of doubtful records or related to species no more found in the wild. In this study, 10 Medicago species native to Campania region, and one archaeophyte (M. sativa), identified by means of morphological diagnostic characters, were analyzed in a blind test to assay the efficacy of nine microsatellite markers (five cp-SSRs and four n-SSRs). A total number of 33 individuals from 6 locations were sampled and genotyped. All markers were polymorphic, 40 alleles were obtained with n-SSRs ranging from 8–12 alleles per locus with an average of 10 alleles per marker, PIC values ranged from 0.672 to 0.847, and the most polymorphic SSR was MTIC 564. The cp-SSRs markers were highly polymorphic too; PIC values ranged from 0.644 to 0.891 with an average of 0.776, the most polymorphic cp-SSR was CCMP10. 56 alleles were obtained with cp-SSRs ranging from 7 to 17 alleles per locus with an average of 11. AMOVA analysis with n-SSR markers highlighted a great level of genetic differentiation among the 11 species, with a statistically significant fixation index (FST ). UPGMA clustering and Bayesian-based population structure analysis assigned these 11 species to two main clusters, but the distribution of species within clusters was not the same for the two analyses. In conclusion, our results demonstrated that the combination of the used SSRs well distinguished the 11 Medicago species. Moreover, our results demonstrated that the use of a limited number of SSRs might be considered for further genetic studies on other Medicago species