Homogenization and Trends Analysis of Monthly Precipitation Series in the Fez-Meknes Region, Morocco

High quality and long-term precipitation data are required to study the variability and trends of rainfall and the impact of climate change. In developing countries like Morocco, the quality of climate data collected from various weather stations faces numerous obstacles. This paper presents methods for collecting, correcting, reconstructing, and homogenizing precipitation series of Morocco’s Fez-Meknes region from 1961 to 2019. Data collected from national specialized agencies based on 83 rain gauge stations was processed through an algorithm specially designed for the homogenization of climatic data (Climatol). We applied the Mann-Kendall test and Sen’s slope estimator to raw and homogenized data to calculate rainfall trend magnitudes and significance. The homogenization process allows for the detection of a larger number of stations with statistically significant negative trends with 95% and 90% confidence levels, particularly in the mountain ranges, that threatens the main sources of water in the largest watershed in the country. The regionalization of our rain gauge stations is highlighted and compared to previous studies. The monthly and annual means of raw and homogenized data show minor differences over the three main climate zones of the region

Characterization of Moroccan Coal Waste Jerada Mine): Impact on Physical Properties of Mortars Made of Coal Waste

International audienc

Electrochromic properties of Mo-doped V

In this work, we have studied the Mo effect on V2O5 thin films, the samples were deposited by spray pyrolysis technique on heated glass substrates at 500 °C. The dopant amount was varied at different concentration, 2%, 4% and 6%. Different techniques were carried out, in order to studied the Mo effect on V2O5, such as XRD, Raman, SEM, AFM and electrochemical analysis. From the obtained results, all the samples exhibited orthorhombic structure with (001) predominant orientation. The optical properties of Mo concentration effect were studied in their colored and discolored states. These electrochemical studies were performed in LiClO4 electrolyte with 0.5 mol/L of C4H6O3. The transmittance value of the samples decreased from 76% to 10% at 690 nm, when the samples have changed color, from colored state to discolored state respectively

Optical properties of undoped and tin-doped nanostructured In

Tin-doped indium oxide (In2O3:Sn) thin films in different concentrations (Sn = 0, 3, 5, 8 at.%) were deposited by reactive chemical pulverisation spray pyrolysis on heated glass substrates at 500 °C. The effect of the tin dopant on the nonlinear optical properties was investigated using X-ray diffraction, transmission, electrical resistivity and third harmonic generation (THG). All films were polycrystalline, and crystallised in a cubic structure with a preferential orientation along the (400) direction. The Sn (5 at.%) doped In2O3 thin films exhibited a lower resistivity of 3 × 10-4 Ω cm, and higher transmission in the visible region of about 94%. Optical parameters, such as the extinction coefficient (k), refractive index (n) and energy band gap (Eg), were also studied to show the composition-dependence of tin-doped indium oxide films. The nonlinear properties of the In2O3:Sn thin films have been found to be influenced by doping concentration, and the best value of χ(3) = 3 × 10-11 (esu) was found for the 5 at.% doped sample

Impact of conduction band non-parabolicity and dielectric mismatch on photoionization cross section of donor bound polaron in spherical GaN/InN core-shell nanoparticle

Understanding the behavior of single dopant in semiconductors is a challenge to attain a high control on optoelectronic devices. Based on the fact that the external perturbations have an important impact on properties of doped nanocrystals, we have studied the simultaneous effects of phonons and conduction band non-parabolicity combined to dielectric mismatch and donor position on the photoionization cross section of an off-center donor in spherical GaN/InN core-shell quantum dots. The calculations were carried out within the framework of the effective-mass approximation and the eigenvalues equation has been solved using the Ritz variational method. The examination of the photoionization cross section, corresponding to the first donor energy level and the non-parabolic conduction band optical transition, shows clearly that the existence of non-parabolicity band or dielectric environment causes a blue shift of resonance peaks while the existence of phonon red shift them with a non-neglected variations in their intensity. The donor position has also an important effect on peaks position and amplitude

Assessment of the Sediments Contamination by Heavy Metals of the Cheliff River, Algeria..

International audienc

Analyzing Spatial Trends of Precipitation Using Gridded Data in the Fez-Meknes Region, Morocco

The aim of this paper was to present a precipitation trend analysis using gridded data at annual, seasonal and monthly time scales over the Fez-Meknes region (northern Morocco) for the period 1961–2019. Our results showed a general decreasing trend at an annual scale, especially over the mountain and the wetter parts of the region, which was statistically significant in 72% of the grid points, ranging down to −30 mm per decade. A general upward trend during autumn, but still non-significant in 95% of the grid points, was detected, while during winter, significant negative trends were observed in the southwest (−10 to −20 mm per decade) and northeast areas (more than −20 mm per decade) of the region. Spring rainfall significantly decreased in 86% of the grid points, with values of this trend ranging between 0 and −5 mm per decade in the upper Moulouya and −5 to −10 mm per decade over the rest of the region (except the northwest). At a monthly time scale, significant negative trends were recorded during December, February, March and April, primarily over the northeast Middle Atlas and the northwest tip of the region, while a significant upward trend was observed during the month of August, especially in the Middle Atlas. These results could help decision makers understand rainfall variability within the region and work out proper plans while taking into account the effects of climate change

Analyzing Spatial Trends of Precipitation Using Gridded Data in the Fez-Meknes Region, Morocco

The aim of this paper was to present a precipitation trend analysis using gridded data at annual, seasonal and monthly time scales over the Fez-Meknes region (northern Morocco) for the period 1961–2019. Our results showed a general decreasing trend at an annual scale, especially over the mountain and the wetter parts of the region, which was statistically significant in 72% of the grid points, ranging down to −30 mm per decade. A general upward trend during autumn, but still non-significant in 95% of the grid points, was detected, while during winter, significant negative trends were observed in the southwest (−10 to −20 mm per decade) and northeast areas (more than −20 mm per decade) of the region. Spring rainfall significantly decreased in 86% of the grid points, with values of this trend ranging between 0 and −5 mm per decade in the upper Moulouya and −5 to −10 mm per decade over the rest of the region (except the northwest). At a monthly time scale, significant negative trends were recorded during December, February, March and April, primarily over the northeast Middle Atlas and the northwest tip of the region, while a significant upward trend was observed during the month of August, especially in the Middle Atlas. These results could help decision makers understand rainfall variability within the region and work out proper plans while taking into account the effects of climate change