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Barchans are characterized by a symmetric shape independently of their stage of development and the axis of symmetry parallels to the dominant wind direction. However, shape of the dunes can be modified by several factors, among which most important are: change of wind regime, dune collisions or interaction of closely spaced dunes, ground surface relief, asymmetric sediment supply. The aim of the study was to analyze the impact of short-term (diurnal) and long-term (seasonal) changes in wind direction and velocity on shape of barchan dunes. The study was conducted in southern Moroccan area of Western Sahara, between Tarfaya and Laâyoune. This area is characterised by significant variability of active wind (RDP/DP=0,66) which is unfavourable for barchans development. Measurements were conducted in two spring seasons of 2011 and 2012 and two autumn seasons of 2007 and 2011. 52 isolated barchans were selected for detailed studies. Based on GPS-RTK measurements, precise 3D models of the landforms were obtained allowing the detailed analysis of dune shapes. Changes of basie morphological parameters were analyzed as well as shape changes occurring the windward slope and within dunes horns. The shapes of the barchans were correlated with the short-term and the long-term wind regime. It was found that basic morphological parameters are not good indicators of wind variability, with the exception of barchan horns lengths which change according to the seasonal wind regime. Short-term wind regime changes are well registered by: i) "collars" developing along the dune crestlines, ii) "tongues" developing at the ends of dune horns and iii) location of the dune apex. On the other hand, beaded horns testify for very strong wind. I was found, that mentioned features develop and undergo modification during first days or even hours of changed wind regime. The analyzes of barchan shapes, performed in different seasons, proved that even a several-month long period of highly diversified wind regime does not change basie shape of the barchans. Therefore, it can be inferred that barchans development does not depend exclusively on wind regime.
The paper describes the results of research in the Upper Dades Valley in the High Atlas Mountains in Morocco. The purpose of the research was to identify the impact of river channels changes, fluvial accumulation nad erosion on human activity. Fieldwork and maps were used to characterize the structure of the Dades river channel and the intensity of present-day fluvial processes. Research data show that the Upper Dades Valley is shaped primarily by short but frequent and intense hydrometeorological events. The structure of the Dades river channel indicates a complex functionality. Tributary episodic riviers and gorges sections supply most of the weathering material. Narrow sections of Dades channel serve for material as transfer zones, while deposition occurs across broader areas. Research has shown that extreme fluvial processes occurring in semi-arid mountains result in fast river chanels changes and accelerated deposition of weathering material across valley floors, which usually leads to limits on the development of agriculture in such areas.
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Źródło wilgoci w barchanach Sahary Zachodniej

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The aim of the study was to determine the impact of climatic and meteorological conditions on aeolian sand transport within barchans. The study area was located at Western Sahara, around the towns of Tarfaya and Laâyoune. Particular attention was paid to the factors that increase the moisture content of the surface and subsurface layers of sand dunes. It could be one of the important factors to have an influence on threshold wind velocity. Western Sahara dune fields are situated in the zone of the dominant wind direction from the northern sector, which determines the barchan dunes shape and orientation, as well as the supply of moisture from the Atlantic Ocean. The results of investigations confirm that dunes receive quite a lot of moisture from rainfall and such phenomena as fog as well. Studies have confirmed that the water supply from the fog is comparable to, or even exceeds the amount of water from rainfall in the area. Wetted surface layer reduces the transport of aeolian material, even in case of a wind speed greater than 4-5 ms⁻¹. The presence of fog and dew does not affect the moisture of the deeper sand layers, which occurs after rainfall. Analysis of aeolian sand transport within the barchan dunes in the areas such a Western Sahara, should not be therefore limited to the measurement of wind speed and its direction. It must include the investigations on other meteorological elements, especially air temperature and humidity conditions, responsible for the amount of atmospheric deposits on the dune surface.
Z racji bezpośredniej bliskości geograficznej i złożonej sieci powiązań historycznych, politycznych, gospodarczych i społeczno- kulturowych, Unia Europejska od lat sześćdziesiątych buduje relacje z państwami basenu Morza Śródziemnego, regionu zwanego MENA (Middle East and North Africa), przy czym szczególne miejsce w jej polityce zajmują państwa Maghrebu — Królestwo Maroka, Algierska Republika Ludowo-Demokratyczna i Republika Tunezji. Polityka śródziemnomorska Unii Europejskiej ulegała ewolucji na przestrzeni lat, co zarazem miało -wpływ na jej skuteczność. Artykuł ma na celu prześledzenie tej ewolucji oraz ocenę skuteczności polityki unijnej na przykładzie osiągnięć transformacji państw Maghrebu. Pierwsza część artykułu przedstawia zarys polityki śródziemnomorskiej do 2005 roku tj. do momentu sformułowania Europejskiej Polityki Sąsiedztwa oraz związanych z nią Planów Działań., Część druga dotyczy okresu późniejszego i zawiera całościową ocenę procesu euro-śródziemnomorskiego, oraz jego implikacji dla Polski jako kraju członkowskiego UE.
Three mammalian molars from the Early Cretaceous of Morocco reveal the existence, at that time, of two new and peculiar species, one of them assigned to the Eotheria Triconodonta (uncertain family), Dyskritodon amazighi gen. et sp. n., the second only tentatively assigned to the Triconodonta, Ichthyoconodon jaworowskorum gen. et sp. n. The former is represented by a last lower molar which three main cusps (a, c, d) decrease regularly in size posteriorly while cusp b is very small and lingually situated, a unique condition for post-Liassic triconodonts. The second taxon (two specimens) is characterized by very narrow and trenchant teeth not intermeshing with adjacent ones, and carrying three subequal main cusps (b, a, c). Such dental morphology suggests that these mammals might have been semi-aquatic and piscivorous.
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