The aim of this present study is to determine the physicochemical properties of atmospheric particles in commune 5 of the Niamey region. For this purpose, the determination of the atmospheric physical and chemical properties was carried out using a low-volume sampler, a Davis-type weather station, a balance high sensitivity, The Thermo XL2 and the black carbon reflectometer. The pollutants concerned by this study are mainly fine particulate matter (PM2.5), black carbon and heavy metals such as Cr, Cu, Hg, Mn, Ti, V, Zn, Ba, Fe and Sr. According to the result of this study which is carried out over 30 days, the PM2.5 concentrations of air measured were between 0 and 286.54 μg/L with a mean value of 11.65 μg/L. The temperature values were between 24 and 27 °C with an average value of 25.3°C. The humidity value of measured air varies between 8 and 17 % with a mean value of 13.3 %. The measured wind speed values are between 3.24 and 6.48 Km/h with an average value of 4.14 Km/h. According to World Health Organization guidelines the PM2.5, Mn, Hg, Ba, Cr and black carbon concentrations measured during this study exceeded the permissible limit values. Correlation analysis results highlighted a strong correlation between Mn-Fe, Mn-Zn, Mn-Ti, Mn-V, Mn-Cr, Zn-Ti, Zn-V, Zn-Cr, Ti-V, and Ti-Cr indicating that these ions come from a common source. According to principal component analysis for heavy metals, three principal factors that explain 87.34% of the total variance have been formed. Component 1 includes V, Zn, Ti and Cr with a variance value of 56.067 %; the second factor includes Ba and black carbon with a variance value of 19.665 % and the third factor is only represented by Sr with a variance value of 11.612 %. The high value of variance observed in the first group of components indicated that V, Zn, Ti and Cr are the main pollutants that control the air pollution in the study area.

The SOMAÏR open-pit uranium mine, commonly known as « Société des Mines de l’Aïr Aïr » (Arlit, Northern Niger), has been using the topographic method for several years to monitor and estimate mine production. However, the method has limitations and constraints in the implementation and reliability of the results. The company is considering the use of an innovative, more reliable and economical method. Thus, a pilot project using drones is being implemented. The objective of this work is to carry out a comparative study between the topographic method and the photogrammetric method for monitoring and acquiring data from mining operations. Thus, the data acquired by topometry using a total station, for the so-called classical method and by drone for the photogrammetric method, were analyzed and interpreted. These two (2) methods were used for the follow-up of the M4_Art North ore deposit and the G4_Taossa pit of the SOMAÏR mine. The results of the analysis and processing show that the data acquisition time by drone is relatively low (30 to 40 minutes) compared to that of the topographic surveys (21 to 60 minutes). However, data processing times for the photogrammetric method are relatively higher (50 to 60 minutes) than those for the conventional method (14 to 20 minutes). Nevertheless, this processing time of drone images can be improved with powerful computer equipment. In addition, the use of UAVs offers additional advantages in the monitoring of mining operations, particularly with regard to worker safety, precision in the calculation of dimensions, volumes and tonnages at the mining slice and at the overburden.  Immediate analysis of the two methods shows the accuracy of the drone for the front survey and also shows all the details present on the ground, namely: the machines used, the purging products and other products or elements used. So, it would be wise to opt for the drone in downhole activities.

The aims of this study is to identify the behavior of the sealing grout in the Izegouandane and Tarât aquifers, which are the main water supply sources in the northern region of Niger, in order to prevent contamination and reduce the impact of uranium mining activities on the groundwater. This study also made it possible to evaluate the conformity of the mixing water as well as the bearing capacity of the grout in the aquifers crossed in order to verify its conformity. The study area is located in a desert zone in the northern band of Niger, in Arlit city. The measured compressive strengths are 60 bars for cylinder A, 52.5 for cylinder B and 62.5 for cylinder C with an average value of 58.33 bars. The deduced base stress value is 2.24 MPa. The sampled mixing water has a pH of 8.7 with a suspended solids content of 0.02g/l, a Cl- concentration of 93 mg/l and nitrate and nitrite concentration values that are 5 mg/l and 12 mg/l respectively. These waters comply with the general specifications of the standards relating to the quality of mixing water and can therefore be used to fill in boreholes. The analysis of groundwater shows that for Izegouandane and Tarat aquifers the values of concentration of suspended solids are respectively 0.04 g / L to 0.001 g / L. The values of Ph of these waters are 8.7 and 8.1 respectively for the water table of Izegouandane and Tarat. The analysis of Izegouandane aquifer showed that the concentrations of chloride, nitrates and sulfates are respectively 32 mg/L, 9 mg/L and 36 mg/L. Those of magnesium, ammonium and carbon dioxide, they are respectively 1.5 mg/L, 0.8 mg/L and 0.5 mg/L. For the Tarat aquifer, the concentrations of chloride, nitrates and sulphates are respectively 47 mg/L, 29.5 mg/L and 47 mg/L. As for magnesium, ammonium and carbon dioxide, they are respectively 10.02 mg/L, 1.6 mg/L and 1.6 mg/L.

The purpose of this study is to determine the hydrological characteristics and the morphometric parameters of the Sokouraba watershed (BV) where the climatic hazards make the water resource increasingly insufficient. This watershed has never been the subject of morphometric and hydrological characterization in the past. The present study made it possible thus, to better understand the functioning of the hydrographic networks as well as the quantity of water likely to be used for the construction of a dam in this watershed. According to the hydrologic analysis results, from 1960 to 2019, the annual precipitation values range from 347,3 to 1596,6 mm with an average of 1099,28 mm. The maximum daily rainfall values for the same period vary between 42 and 287 mm with an average of 82.85 mm. The values of wet decennial and wet quinquennial rainfall are respectively 1380 and 1280 mm. The dry five-year and dry ten-year rainfall values are 917 mm and 821 mm respectively. According to the watershed characterization results, the calculated Sokouraba watershed surface is 77,34 Km² and its perimeter is 44,3 Km. The values of the length and the width of the equivalent rectangle of the basin are respectively 17,81 Km and 4,34 Km. The longitudinal slope and the overall slope index values are 3.24 m/km and 3.20 m/Km respectively. The value of the corrected overall slope index of the watershed is 7.05 m/Km while the Gravelius compactness index is 1.42. This value of KG higher than 1 indicates that the watershed of sokouraba is of elongated shape. The specific gradient value of the watershed is 61.99. This value is included between 50 and 100 m, thus according to the classification of the reliefs the latter, the relief of the catchment area of Sokouraba can be qualified as moderate. The values of the length of the main watercourse and the total length of the watercourses calculated are respectively 15,41Km and 63,25 Km. The calculated value of the drainage density of the catchment area is 0.21 Km-1. The value of the attenuation coefficient and the ten-year rainfall calculated in this study are 0,78 and 100,062 mm respectively. The value of the decennial runoff coefficient thus calculated is 27,83%.