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Use of Spatial Remote Sensing to Study the Temporal Evolution of the Water Retention of Al Massira Dam in Morocco

Bounif Mohammed, Rahimi Abdelmejid, Boutafoust Rachid, El Mjiri Ikram

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

340--349

EN

In Morocco, irrigated agriculture is still very much linked to the climate and the water retention of dams. With climate change, this country is experiencing recurrent drought, which has led to deficits in water inflow from the rivers to the various dams. The Al Massira dam, the area of study, does not escape this trend. This dam is the only surface water source for the irrigated area of Doukkala. Therefore, special attention must be paid to monitoring this resource at this dam. Thus, the proposed study examined the possibilities offered by spatial remote sensing to improve the current information system. It aims to evaluate this dam’s reservoir by exploiting the data generated by using satellite images. The Landsat satellite images were used to assess the area of this dam by adopting an approach combining spectral indices with thresholding. Then, the existing relationship between the area of the dam lake were examined, determined by spatial remote sensing and its water retention measured in situ. The results obtained revealed a strong correlation between the two parameters. Therefore, a study was conducted to find the best model for predicting the dam’s impoundment based on its lake. The second-degree polynomial model showed a better performance. Given the results obtained, it is recommended to use geospatial methods in the current and prospective monitoring and steering system of water resources.

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Hydrochemical and isotopic methods of identifying the impact of irrigation on the quality of groundwater: a case study from the guelma-bouchegouf region, ne Algeria

Soltani Akram, Djabri Larbi, Fehdi Chemseddine, Bouguerra Hamza, Salah Eddine Tachi

Geomatics, Landmanagement and Landscape

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2023

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no. 4

211--233

EN

The Guelma-Bouchegouf irrigated perimeter uses water from the Bouhamdane dam between May and the end of October. It should be noted that the water is channelled to the perimeter via Seybouse Wadi, which serves as a water collector. The water is supplied during the dry season, which causes water pollution due to strong evaporation and industrial discharges. Moreover, during the summer period irrigation increases since the crops grown are industrial tomatoes, melon, watermelon and beans, requiring intense and sustained watering. The measurement of the conductivity of the water flow shows a clear increase from 3000 μs/cm to 6000 μs/cm. This increase is connected to interactions between water and rock, compounded by the adverse impact of climate change. It should be noted that during this period the average temperature is 26°C and sometimes temperature values exceeding 40°C are recorded. In addition, industrial discharges into the Seybouse Wadi occur without pre-treatment, leading to water pollution by heavy metals. The results of the analyzes of the Seybouse Wadi waters show the presence of pollutants such as iron, manganese, zinc, copper and nutrients in the upstream zone (Guelma region). In the downstream area (Annaba) we notice the presence of pollutants such as chromium, lithium, iron, manganese and nutrients.

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Geospatial Assessment of Soil Organic Matter Variability at Sidi Bennour District in Doukkala Plain in Morocco

Bouasria Abdelkrim, Ibno Namr Khalid, Rahimi Abdelmejid, Ettachfini El Mostafa

Journal of Ecological Engineering

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2021

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Vol. 22, nr 11

120--130

EN

Understanding the spatial variability of soil organic matter (SOM) is critical for studying and assessing soil fertility and quality. This knowledge is important for soil management, which results in high crop yields at a reduced cost of crop production and helps to protect the environment. The benefits of an accurate interpolation of SOM spatial distribution are well known at the agricultural, economic, and ecological levels. It has been conducted this study for comparing and analyze different spatial interpolation methods to evaluate the spatial distribution of SOM in Sidi Bennour District, which is a semi-arid area in the irrigated scheme of the Doukkala Plain, Morocco. For conding this study, it was collected 368 representative soil samples at a depth of 0–30 cm. A portable global positioning system was used to obtain the location coordinates of soil sampling sites. The SOM spatial distribution was performed using four interpolation methods: inverse distance weighted and local polynomial interpolation as deterministic methods, and ordinary kriging and empirical Bayesian kriging as geostatistical methods. High SOM levels were concentrated in vertisols, and low SOM levels were observed in immature soils. The average SOM value was 1.346%, with moderate to high variability (CV = 35.720%). A low SOM concentration indicates a continuous possibility of soil degradation in the future. Ordinary kriging yielded better results than the other interpolation methods (RMSE = 0.395) with a semivariogram fitted by an exponential model, followed by inverse distance weighted (RMSE = 0.397), empirical Bayesian kriging (RMSE = 0.400), and local polynomial interpolation (RMSE = 0.412). Soil genetics and the strong influence of human activity are the major sources of SOM spatial dependence, which is moderate to low. Low SOM content levels (< 1.15%) were present in the southwestern and eastern parts of the digital map. This situation calls for the implementation of specific soil recovery measures.