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Potential use of alluvial groundwater for irrigation in arid zones - Mhamid Oasis (S Morocco)

Dłużewski M., Kozłowski R., Szczucińska A.

Ecological Chemistry and Engineering. S

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2017

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Vol. 24, nr 1

129-140

EN

In arid zones, the availability of fresh water is usually very limited because of high salinity, which greatly limits their use for irrigation purposes. High mineralization of water used for irrigation leads to increased soil salinity. The aim of the study was to examine the potential use of alluvial groundwater for irrigation in arid zones. The works were conducted in the Middle Draa Valley in southern Morocco (the Mhamid Oasis) in October 2015. Water samples of alluvial groundwater were collected for laboratory analysis from 42 wells located in the oasis. In order to determine the possibility to use the water for irrigation purposes, the Sodium Adsorption Ratio (SAR), sodium percentage (%Na), permeability index (PI), Kelly’s ratio (KR), magnesium hazards (MH) and electrical conductivity (EC) were assessed. EC values, exceeding 3000 μS·cm-1 in all the samples, classify the water as unsuitable for irrigation. MH and the KR indexes show that 30% of water samples represent levels making them unsuitable for irrigation. SAR confirms the very high degree of susceptibility of the analyzed waters to salinity hazard. The PI index of these waters is moderate, however in terms of sodium content they can be deemed suitable for irrigation purposes. It has been found that even within a small area of the oasis, a very large differentiation in the alluvial groundwater suitability for irrigation purposes occurs.

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Morphodynamics of small high-mountain wadis in arid zones (on the examples of the tributaries of the upper Dades River, High Atlas Mountains, Morocco)

Dłużewski M., Krzemień K., Rojan E., Biejat K., Kokosiński Ł.

Landform Analysis

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2013

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Vol. 22

9--19

EN

The paper reports on a study of the impact of morphology and lithology of small catchments on episodic river channel development in the southern High Atlas Mountains in Morocco. A detailed analysis focused on three catchments of small wadis featuring different relief and lithology along the upper, middle and lower course of the Dades River. The fieldwork combined with an analysis of topographic and geological maps and of satellite images concluded that the development of the river valley and channel structures was related to the main stages in the development of the landform in this part of the High Atlas. The channel dynamics were found to be typical of arid mountains, which was particularly apparent within a denudational-and-fluvial zone that reached up to 3,000 m a.s.l. The dominant morphodynamic system of this zone was pluvio-gravitational where episodic heavy rainfall events triggered fast displacement of stone mantle covers down the slopes and into the river channels. An analysis of the deposition zones in the lower channel reaches and on alluvial fans at the confluence of the side valleys and the main valley leads to the conclusion that the main factor, which determines the channel morphology is the impact of debris flows and heavily loaded streams and rivers. The deposited material is then transported outside the mountain zone and deposited within broad river channels. The development of the river channels in the three catchments depends on their order, morphometric property, slope lithology and the amount of material received from the slopes.

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Zróżnicowanie procesów eolicznych w kształtowaniu wydm południowego Maroka

Dłużewski M.

Landform Analysis

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2008

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Vol. 9

183--186