Region Of Jijel Research Articles

Mass insulation enhancement of cork stoppers through heat treatment: experimental measurements, modeling, and optimization

Natural cork stoppers, used as bottle sealers for high-end products such as ingredients and flavorings, belong to the highest class in terms of cork quality. Various studies have been carried out to examine the solute diffusion in cork using conventional methods. However, the investigations were limited to natural cork stoppers that had been boiled and cut in a single direction. In this study, the anisotropic cylindrical shape of cork samples was modeled, considering various cutting directions. Additionally, we subjected the stoppers to boiling then to an optimal THT cycle to improve the cork's mechanical qualities. The optimal thermal cycle is determined using TGA analysis. IR and SEM tests are employed to verify the enhancements in the cork. The apparent mass diffusion coefficient (Dapp) is determined by the calibration of the model with the experimental data acquired via the conductometric method. The coefficient values are optimized using the Bat algorithm with a relative error of 10–5. The Dapp was found to be better for the treated cork grown in the Jijel region than for the cork Medea, which is better than of Skikda cork. Regarding the impact of the cutting direction on the Jijel's cork, the results indicate that the mass insulation is higher when the treated stoppers are cut in the tangential-longitudinal direction (DJTLt=4,12.10-13m2s-1) compared to the tangential-radial direction (DJTRt=7,75.10-13m2s-1) and the longitudinal-radial direction (DJLRt=8,53.10-13m2s-1). The treatment, which serves as a solution for the cork industry, showed an improvement in mass insulation 13-fold greater than the natural cork.

Seroprevalence and risk factors of Toxoplasma gondii infection among goats in Algeria

Toxoplasmosis is one of the most common zoonotic parasitic diseases worldwide and is caused by Toxoplasma gondii. It is implicated in reproductive disorders in small ruminants. This study aims to determine, for the first time in Algeria, the seroprevalence and associated factors of T. gondii infection in goats. The study was conducted in four regions, Ghardaia, Laghouat and Djelfa, southern Algeria, and Jijel region, northern Algeria. A total of 92 blood samples were collected including 74 females and 18 males. All sera were tested using an enzyme-linked immunosorbent assay (ELISA) to detect the T. gondii antibodies. The presence of anti-T. gondii antibodies was detected in 35 out of 92 goats (38.04%) (95% CI: 31.64%–44.44%) and in all flocks (100%). Risk factors that have a significant influence on the seroprevalence of T. gondii infection are breed, regions, production system, presence of cats, clinics and abortion history. However, variables such as age and gender were note significantly associated with toxoplasma infection in goats. The highest seroprevalences of infection was observed in saanen (52.94%) (p<0.001) and cross-breed race (44%) (p<0.01) in comparison with other breeds. Regarding regions, Jijel and Laghouat were most infected with seroprevalences of 50% (p<0.001) and 40.91% (p<0.01), respectively. Animals in intensive production systems were most infected, showing a seroprevalence of 51.85%, in comparison with extensive (28.13%) and semi-intensive systems (36.36%) (p<0.001). The presence of cats in farms was significantly associated with high seroprevalence (44.64%) (p<0.001). The infection was more prevalent in previously aborted females (50%) than females that had never aborted (3.35%) (p<0.001)and animals that have diarrhoea or poor health (41.67%) were significantly more infected than healthy animals (37.50%) (p<0.01). Seroprevalence in males (38.89%) was very close to those in females (37.84%) (p>0.05). Age-related seroprevalence did not vary significantly (ranged from 36.37% to 40%) between the three age classes. These results indicate that goat toxoplasmosis is widespread in Algeria, and goats may represent a high risk of contamination for humans. This requires more attention during consumption of goat meat.

Ethnobotanical Study on the Traditional Use of Pistacia lentiscus L. Among the Local Population of Northern Central-East Region of Algeria

The botanical heritage of a region is an important resource for local people, which allows them to treat themselves with plants that have already been experienced from generation to generation for their benefits and effectiveness. The aim of this study was to highlight the different uses of lentisk pistachio products in the region of Jijel (Algeria). Systematic surveys have been carried out among different categories of people, by age group; have shown a growing interest in the use of medicinal plants. Two approaches (observation, and interview) were used to support this study, with an ethnobotanical worksheet, to obtain other recipes and more information on lentisk benefits and uses. The survey data processing showed that the lentisk is used for therapeutic purposes, to treat diseases of the skin (29%) and respiratory system (28%). The main and most used part of the plant is its berries. The plant is harvested in a spontaneous state and the picking of berries is done from November (in winter). Oil extraction is the principal preparation (72%). The use of resinous gum was not mentioned. Ten percent of surveys gave culinary recipes for some traditional meals preferred by Jijelians. The current study highlighted the ancestral practices and uses of the lentisk by Jijelians. It is necessary to develop this niche and promote its value chain in order to consolidate the economy of the local population.

Investigation of physicochemical characterization and magnetic enrichment of iron ore from Sidi Maarouf deposit

The establishment of a new metallurgical complex in Bellara, located in El-Milia in the Jijel region, is geographically advantageous due to its proximity to the Sidi Maarouf deposit (Algeria). This proximity has been a fundamental motivation for the completion of the current study. The object of research is the quality of iron products from Sidi Maarouf. The research is aimed at developing a treatment process aimed at improving the quality of iron products from Sidi Maarouf, while reducing the impurities of quartz and clay present in this ore. This approach will be based on an approved technological treatment scheme, implemented through an experimental approach to ensure reliable results that meet the requirements of the steel industry. The problem issue revolves around the difficulties encountered in the production of steels due to the natural characteristics of the raw material. In the absence of a physico-chemical characterization of the Sidi Maarouf iron ore deposit, samples taken undergo a series of thorough analyses, including microscopic examinations, X-ray diffraction (XRD), as well as additional chemical analyses using X-ray fluorescence (XRF). The identified minerals are predominantly composed of hematite in terms of iron. As for the gangue, it is mainly composed of calcite and quartz. Through to the pre-treatment process involving washing, we have successfully removed lightweight particles, resulting in a concentrate containing dense particles. This approach was crucial in achieving satisfactory results during the high-intensity dry magnetic separation. As a result of the research it is shown that the enrichment of the Sidi Maarouf iron ore through high-intensity dry magnetic separation, a final concentrate was obtained with a Fe2O3 content exceeding 67 %, along with a significant reduction in silica impurities to 0.92 % and alumina to 0.77 %. It was concluded that this concentrate, derived from the -1+0.5 mm fraction and obtained under a current intensity of 12 A, meets the requirements of the steel industry. Following the work carried out, it is found that the methods of valorization of iron ore through mineralogical processes consistently require a high level of efficiency and performance in terms of equipment and characterization of the products obtained. In the future, iron ore processing will be conducted using innovative methods, integrating advanced technologies to enhance its characteristics while adopting environmentally friendly practices.

Ability of arbuscular mycorrhizal to protect tomato (Solanum lycopersicum) seedlings from Fusarium oxysporum

Present experiments were conducted in the microbiology laboratory, Department of Environmental and Agronomic Sciences and in a private nursery in the Tassoust region of Jijel during 2021 and 2022. This study was carried out on the use of strains of arbuscular mycorhizal fungi (Acaulospora sp. and Glomus sp.) as a means to control F. oxysporum effect. After 15 days of inoculation, several measurements of the lengths roots, stem and leaves were noted and symptoms of Fusarium disease were also recorded. The results revealed that F. oxysporum is a pathogen for tomato (Solanum lycopersicum L.) plants (super strain) variety, causing Fusarium disease of this host, which manifests by yellowing, wilting and necrosis of aerial parts, and reduced growth parameters in plants. Therefore, the disease incidence after 15 days of inoculation is estimated at 75 and 50% for (T1 and T3) respectively. In addition, our results revealed that the percentage of incidence was 100 and 25% respectively for T1 and T3 after 22 days. Whereas, the results showed that mycorhizal fungi are associated with the roots of tomato plants. They reduced the incidence rate of Fusarium disease by 50% (T3) and improved the growth of tomato seedlings (Super strain) which manifests itself by a vigorous root system and a very important development of the aerial parts. These results indicate that arbuscular mycorhizal fungi can effectively contribute to the ecological management of soil-borne fungal disease.

The first study on seroprevalence and risk factors of Neospora caninum infection in pregnant local cows from Northeast Algeria.

Background and Aim:Neospora caninum is one of the most common infectious organisms worldwide that causes abortion in cattle. To the best of our knowledge, no previous studies have focused on N. caninum infection in the local Atlas brown cattle from Northeast Algeria. This study aimed to assess the importance of bovine neosporosis for causing abortion in Atlas brown cattle and to identify selected risk factors.Materials and Methods:A case-control study was performed on 60 control farms and 30 case farms. We collected 650 blood samples from 650 pregnant cows from 90 farms in five Algerian provinces; Jijel, Skikda, Annaba, El-Tarf, and Souk-Ahras. Sera samples were analyzed for the presence of antibodies against N. caninum using enzyme-linked immunosorbent assays.Results:The seroprevalence of N. caninum infection in the cows was 36.2% (95% confidence interval [CI]: 32.7-39.8) and in the farms was 81.1% (95% CI: 73.0-89.2). Risk factors found by multivariable logistic regression included: Presence of dogs (odds ratio [OR] 4.7, 95 CI 2.9-7.3); age ≥84 months (OR 4.9, 95 CI 2.8-8.3); Jijel region (OR 2.2, 95 CI 1.1-4.5); white (OR 2.5, 95 CI 1.4-4.4) and gray (OR 2.5, 95 CI 1.4-4.5) coat; moderate (OR 2.30, 95 CI 1.4-3.8) and bad (OR 3.1, 95 CI 1.8-5.3) hygiene; and second (OR 2.5, 95 CI 1.4-4.4); and last (OR 2.3, 95 CI 1.3-4.2) stage of pregnancy. Our case-control study showed no significant association between seropositivity of N. caninum and abortion at the farms level (OR 0.9, 95 CI 0.3-2.7). Similarly, there was no significant association between seropositivity of N. caninum and abortion at the individual level (OR 0.8, 95 CI 0.6-1.2).Conclusion:This is the first study of N. caninum infection in pregnant local cows from Northeast Algeria. The prevalence rate of antibodies against N. caninum was high. Almost all risk factors studied for infection were significantly associated with seroprevalence. Our analysis showed no relation between N. caninum infection and abortion. Consequently, these local cows are resistant to abortion caused by N. caninum.

Assessment of surface water quality: a case of Jijel region, North-East Algeria

Assessment of surface water quality: a case of Jijel region, North-East Algeria

Effects of substrate on the germination and seedling growth of Quercus suber L.

Abstract The seedling quality is one of the most important factors for the success of reforestation programs. In this sense, this work aimed to evaluate the effects of substrate on the germination of cork oak acorns from El Aouana forest, located in the Jijel region of north-eastern Algeria, and on the performance of seedlings, particularly their growth. The experiment was performed in the nursery of the Tlemcen Forest Conservation. For this purpose, five substrates were used: S1 (sand), S2 (topsoil), S3 (potting soil), S4 (1/2 sand + 1/2 topsoil) and S5 (1/3 sand + 1/3 topsoil + 1/3 potting soil). Germination and survival rates, and seedling morphological traits: average height of seedlings, average root collar diameter, stem height/root collar diameter ratio (H/D), average number of leaves per plant, leaf length, leaf width and leaf area, were evaluated. Results obtained after 16 months of monitoring in the nursery showed high germination rates of 91.4%, with an average survival rate of 89.5%, and significant differences were recorded between the substrates tested. In terms of growth, the best results were obtained with the potting soil substrate (S3) for all parameters. The lowest yields were recorded in seedlings grown on sand alone (S1).

The 13 July 2019 Mw 5.0 Jijel Earthquake, northern Algeria: An indicator of active deformation along the eastern Algerian margin

On July 13, 2019, a moderate earthquake shook the Jijel region of Algeria, ~300 km east of Algiers (Capital of Algeria). In the past, the Jijel region experienced a destructive earthquake (I0: X) on 21–22 August 1856, triggering a moderate tsunami in the western Mediterranean region. The 2019 event is the second important event to have occurred along this part of the Algerian margin, which has been undergoing an inversion process since the Pliocene Epoch. The event occurred 40 km to the north of Jijel City, at 10 km depth. No property damage or injuries were associated with this event. The seismic moment release estimated from waveform modeling was M0 = 3 × 1016 Nm, corresponding to a Mw 5.0 event. The mainshock focal mechanism is associated with the rupture of an E–W thrust fault that is clarified by a 4-km-long × 10-km-wide aftershock cluster along the continental slope of the Jijel margin. In the same area, ~30 km to the west and offshore of the coastal village of Ziama–Mansouriah (west of Jijel) a Mw 4.1 earthquake occurred in 2014. This event is also associated with the rupture of a western contiguous E–W thrust fault. Stress tensor inversion produces a main (σ1) maximum stress axis oriented N356E, which is in agreement with previous stress studies of the Lesser Kabylia–Babors block. The present-day stress field is characterized by a compressional tectonic regime (R' = 2.96 ± 0.21). Coulomb stress analysis of the 2014 Ziama and 2019 Jijel earthquakes indicates that the two earthquakes appear to be individually triggered events with no stress transfer between them. The 2019 Jijel earthquake is associated with one of the three active en echelon faults that have already been identified in the central part of the Algerian margin via recent marine surveys. It belongs to the serie of many moderate seismic events that have recently affected the Algerian margin (Boumerdes, Algiers, Bejaia), and is representative of the active deformation process along the Algerian margin that is marked by the initiation of an incipient subduction zone with a progressive plate boundary migration since the late Miocene.

Identification and incidence of hard tick species during summer season 2019 in Jijel Province (northeastern Algeria).

Ticks are haematophagous arthropodsand tick-borne diseases causes billions of dollars in losses in the cattle industry because of the ability of ticks to be vector for many pathogens. This paper identifies and compares the infestation rate (prevalence and intensity) of females of hard tick species compared to males with respect to sex, age and breed of cattle in the region of Jijel, northeastern Algeria. A total of infested 53 cattle were screened and 1214 ticks were collected manually during summer 2019 (June, July and August) and identified based on their morphology. Seven tick species were identified as infesting the cattle: viz. Rhipicephalus (Boophilus) annulatus, Rhipicephalus bursa, Rhipicephalus sanguineus, Hyalomma marginatum, Hyalomma lusitanicum, Hyalomma scupense, and Hyalomma anatolicum. The predominant tick species recorded is Rhipicephalus (Boophilus) annulatus. The maximum intensity of tick infestation as a function of age is between 3 and 4years and 5 and 6years (39 ticks/cow). The study shows that the comparison between the prevalence of infestation in females and males is significant as a function of sex and breed of cattle. In addition, only the intensity of infestation as a function of the age of the cattle, when comparing the sexes of the ticks, is significant (p < 0.05). This study also provides data for the development of an active control plan based on tick mating strategies for the management of ticks in cattle in Jijel, Algeria.

Comparison of Male and Female Morphometric Indices of the 3-Spot Form of Calliptamus barbarus (Costa, 1836), (Orthoptera: Acrididae: Calliptaminae) in Three Areas in The Jijel Region (Northeast Algeria)

To carried out this study, three stations were chosen These are Texenna, Kissir and Jijel.11 parameters were taken into account for each individual: Total body Length TL, Length of Elytra EL, Length of Femur FL, Width of Femur FW, Width of Head HW, Width of Pronotum PW, Total Femoral Area TFA and Area of Femoral Spots AFS as well as comparisons of FL / FW, EL / FL, and TFA/AFS. In order to analyze the results, the following statistical parameters are used: correlation and conformity test, regression line, and analysis of variance. The correlation between different parameters was initially low, then average, and finally strong. The conformity test gives values obst > t 0.95 between FL/ FW in the females of Texenna and between the males in the 3stations. The same observation is made for the EL/FL in females in the 3 stations and in Texenna males. The difference is not significant between these 2 parameters. The conformity test gave values obs t <t 0.95 for FL/FW only in females from Kissir and Jijel and between EL/FL in males from Kissir and Jijel. Difference is slightly significant. For TFA/AFS, the test indicates a significant difference for males of Kissir and Jijel but a non-significant difference in both females of Texenna and Jijel. Moreover, the linear regression shows that the 3 populations are homogeneous from the point of view of EL/FL, FL/FW, and TFA/AFS couples. Analysis of variance showed that the Fisher statisticF observed is higher than the theoretical F. Despite their apparent differences in size (8 out of 11 parameters gave non-significant differences), we can conclude that the 3 populations living in the Jijel region belong all to a single homogeneous group: the form with 3 femoral spots showing a clear heterogeneity with that of semi-arid bioclimate who contain individuals with big size and having only one femoral spot.

Regional modeling of soil sensitivity to water erosion in JIJEL region (Algeria) using MCA and GIS

Water erosion is a serious problem that threatens more and more soils in northern Algeria and particularly in Jijel region. The potential of its natural and tourist resources makes this region an important ecological and socio-economic area that deserves to be preserved. The main objective of this work is to apply a weighted-sum model to water erosion sensitivity mapping in Jijel region by integrating geographical information system (GIS). Four layers of data modeling factors responsible for soil erosion vulnerability were combined: precipitation, topography, lithology, and vegetation cover. The resulting water-erosion sensitivity map enabled distinguishing areas most threatened by erosion; 77% of the total area was found to be highly susceptible to water erosion, mainly caused by steep slopes and vegetation cover degraded by summer fires. The sensitivity map was validated by the high statistically significant value of chi-square test and is, therefore, a solid tool on which local decision-makers can rely to define priority protection areas.

Altitude Effect on the Properties of Honeys from the Region of Jijel (Algeria)

1. Alderman, D.J., Smith, P. (2001). Development of draft protocols of standard reference methods for antimicrobial agent susceptibility testing of bacteria associated with fish diseases. Aquaculture, 196(3-4), SI, 211–243. CrossRef Google Scholar

Water-Saving Technologies and Total Factor Productivity Growth in Small Horticultural Farms in Algeria

Investment in water-saving technologies (WST) was always considered as a solution to manage water demand. Indeed, the adoption of these techniques allows the use of less water in the agricultural production process. Actually, the WST have been widely promoted in Algeria in the last two decades. However, little research exists to support popular claims about their effectiveness. This study aims first, to identify the inputs use differentials between farmers using WST and traditional techniques (gravity irrigation) and, second, to evaluate the impact of WST use on total factor productivity growth (TFP) and determine the contribution of the different inputs in the overall TFP growth of small-scale horticultural farms in the northeastern Algeria (Jijel region). The Tornqvist-Theil index was used for the computation and decomposition of TFP. The results show that the differences of water consumption, gross margin, water productivity and water value indicators between the two groups of farms are statistically significant at 5%. The output growth differential between WST users and non-users is on average 12.73%. It is composed of 6.65% from input growth and 6.08% from TFP growth. Alternatively, output could be increased by 6.08% in average when using the same amount of input. These findings indicate the potential impact of WST on TFP gain. These findings provide helpful information for policy makers to expand the use of these technologies for a better use of irrigation water.

Protection by some plant methanol extracts of cherry tomatoes (Solanum lycopersicum var. Cerasiforme) from fungic infection by Alternaria alternata

Cherry tomato is very susceptible to fungal infections that can cause considerable damage in crops and during storage. Alternaria infection is one of the most common and dangerous alterations for this fruit. They are caused by Alternaria alternata or some other species belonging to the same genus. In this work, we tested the antifungal activity of methanol extracts from five plants harvested in the region of Jijel (Algeria) on A. alternata. The activity was first tested in vitro and then on greenhouse cherry tomato plants: extracts were applied to healthy plants before infection in order to test their preventive action, and after infection to determine whether they are able to knock out Alternaria. Results showed that Rosmarinus officinalis and Lavandula angustifolia extracts were the most active in vitro on A. alternata. Microscopic observations of the mold indicated that these extracts inhibited the dictyospores production. The antifungal activity tested on the plants grown in greenhouse revealed that R. officinalis extract still was the most active. Extracts of L. angustifolia and Punica granatum did not protect the plants from Alternaria infection, but provided a total cure at the end of the treatment. Extracts from Quercus suber and Eucalyptus globulus were the least active. They did not bestow any protection nor complete healing of the plants. Dictyospores counting on fruits at the end of the treatment confirmed the results obtained for the greenhouse crops.

Characteristics and firing behaviour of the under-Numidian clay deposits from the Jijel region (northeast Algeria): potential use in the ceramics industry

AbstractThe Numidian Aquitano-Burdigalian nappe from the Jijel region (northeast Algeria) shows an important clay-rich basal series. In this study, seven representative clay samples were collected from the Djimla and El-Milia areas of this region in order to analyse their mineralogy using X-ray diffraction and Fourier-transform infrared spectroscopy, chemical composition by X-ray fluorescence, particle size, plasticity, morphology by scanning electron microscopy and their ceramic properties. Samples were prepared by pressing the clays and firing them at 800–1100°C, and bulk density, water absorption, linear firing shrinkage, weight loss and bending strength values were determined on the fired samples. The clays are mainly composed of kaolinite and illite, with a small amount of 10–14 Å interstratified clay minerals and chlorite, associated with quartz and feldspars. The main oxides in the samples were SiO2, Al2O3and Fe2O3. The clays may be classified as moderately plastic according to their Atterberg limits. Ceramic tiles have been produced by dry pressing. At all tested firing temperatures, the clays present the required standard values for linear firing shrinkage, weight loss, bulk density, water absorption and bending strength, and they are defect-free. The main transformations were observed at 1000°C with the appearance of new crystalline phases. The measured technological properties of the investigated deposits confirm that the Numidian clays from the Djimla and El-Milia regions are suitable materials for the production of high-quality structural ceramics.

EFFECTS OF IRRIGATION TECHNOLOGY ADOPTION ON FARMS PERFORMANCE IN ALGERIA: A STOCHASTIC FRONTIER PRODUCTION FUNCTION APPROACH

The aim of this study is to evaluate the performance of water-saving technologies (WST) through an investigation of its effect at the farm level. Indeed, the study attempts to estimate the economic value of WST use in Algerian farming, through the comparison of some farm performance indicators between WST adopters, drip irrigation system as a WST, and farmers practicing gravity irrigation as a traditional system. A cross-section data from a survey is conducted in an irrigated perimeter situated in the north-eastern Algeria (Jijel region) encompassing 106 small horticultural farms (including 60 pepper producers and 46 tomato producers). First, the study compares some performance indicators between the two groups of farms. Second, a stochastic production frontier model is used to estimate the productivity gain generated by the WST adoption. Main results show that water consumption, gross margin, and water productivity are statistically significant between the two groups of farms. The average water productivity differential between WST users and non-users is 29% and 25% for tomato and pepper, respectively. The regression model has shown that increasing the WST use by 1% help to increase water productivity of the region by 0.20% for pepper production and 0.11% for tomato production. The findings of this study confirm the hypothesis that WST economize on water quantity, positively affects crop yield and can enhance water productivity.

EFFECTS OF IRRIGATION TECHNOLOGY ADOPTION ON FARMS PERFORMANCE IN ALGERIA: A STOCHASTIC FRONTIER PRODUCTION FUNCTION APPROACH

The aim of this study is to evaluate the performance of water-saving technologies (WST) through an investigation of its effect at the farm level. Indeed, the study attempts to estimate the economic value of WST use in Algerian farming, through the comparison of some farm performance indicators between WST adopters, drip irrigation system as a WST, and farmers practicing gravity irrigation as a traditional system. A cross-section data from a survey is conducted in an irrigated perimeter situated in the north-eastern Algeria (Jijel region) encompassing 106 small horticultural farms (including 60 pepper producers and 46 tomato producers). First, the study compares some performance indicators between the two groups of farms. Second, a stochastic production frontier model is used to estimate the productivity gain generated by the WST adoption. Main results show that water consumption, gross margin, and water productivity are statistically significant between the two groups of farms. The average water productivity differential between WST users and non-users is 29% and 25% for tomato and pepper, respectively. The regression model has shown that increasing the WST use by 1% help to increase water productivity of the region by 0.20% for pepper production and 0.11% for tomato production. The findings of this study confirm the hypothesis that WST economize on water quantity, positively affects crop yield and can enhance water productivity.

Assessment of surface water quality of Mencha River, Northeastern Algeria by index method

Mencha River is one of the largest river in the region of Jijel, Algeria. The human activities such as urban discharges, industrial, agricultural and livestock have significant effects on the quality of water. Because of its importance in the agricultural activities and dense population residing at its banks, the river faces several challenges from various anthropogenic activities. This situation exposes surface water to a severe pollution. The objectives of this study are to use different indexes to assess the current pollution status in Mencha River. Indexes used in this study were Organic Pollution Index (OPI) and Microbiological Quality Index (MQI). Based on the data collected throughout this study, results indicated that the upper reaches of the river (station 01) has had good water quality (OPI=4, MQI=4), while the station 04 presented a poor quality (OPI=2.75, MQI=2.33). Indeed, several pollution sources exist in this site. The agricultural activity, among different sources, was the strongest point in the downstream section of the river, as it contains high amounts of chemicals, causing major decrement in water quality. The used indexes also showed that at stations 02 and 03, the water quality was moderate (OPI=3.25, MQI=3). This study can be used to support the evaluation of regulatory and monitoring decisions.

Preface to the special issue “Seismotectonics and Seismic hazards in North Africa”

North Africa region from Egypt to Morocco experienced several damaging earthquakes in the past, and the largest recorded seismic event reached Mw 7.3 in 1980 at El Asnam (now Chlef) in the Tell Atlas of Algeria. This reality is linked with the regional situation along the Africa–Eurasia plate boundary, or in proximity of the Hellenic Arc plate boundary, or near the midRed Sea spreading floor. This special issue in seismotectonics and relationships with the seismic hazards includes different contributions in seismotectonics, seismology, active faulting, and seismic hazard and risk assessment in North Africa. Specifically, nine articles address the earthquake activity and its effect at the crustal level, Earth surface, and building design. The issue begins with the article of Bezzeghoud et al. that describe the earthquake distribution along the Africa–Eurasia plate boundary and gives the characteristics and seismic strain rate of the tectonically active regions from the Gloria transform fault to NW Africa. Using the tomographic investigations, Timoulali and coauthors explore the crustal structure of the Rif Mountains (Morocco), Alboran Sea, and surrounding areas. A fairly exhaustive account of the earthquake distribution and related active tectonic structures by Bahrouni and coauthors reveals the potential for large earthquakes in Tunisia. Badawy and coauthors describe the seismic activity of east North Africa using relocation procedure and source mechanisms of main continental earthquakes in Egypt. The volume switches into the study of historical earthquakes in Algeria by Ferdi and Harbi using epigraphic documents. Benhamouche and coauthors investigate the surface effects and liquefaction features of past earthquakes in the coastal region of Jijel (east Algeria) that experienced the damaging 1856 earthquakes with tsunami (Io IX, EMS). The evaluation of earthquake hazards and risks represents a natural continuation of previous studies on the seismotectonics of North Africa. The comprehensive analysis of the seismic hazards using an updated deterministic approach provides new results and emphasizes the need for the integration of geological and seismological data along the whole North Africa (Mourabit et al.). Gherboudj et al. present a probabilistic seismic hazard assessment as applied to the Algiers city. Finally, the vulnerability of building design to destructive seismic events is explored through conceptual frameworks and application in Algeria by Mebarki et al. J Seismol (2014) 18:203–204 DOI 10.1007/s10950-014-9424-5