Temperature Variations in Sidi Bel Abbes during the Last Three Decades

The Mediterranean climate of the Sidi Bel Abbes city in northwestern Algeria has not been the subject of many investigations except some sporadic syntheses reports. However, climate change studying its most important parameters has not, at our knowledge, been the subject of a rigorous study. For this purpose this work intends to gather several temperatures ranging between 1980 and 2006 and find a mathematical model that tells us climate changes following changes in temperature during this time interval. Consequently and undesirably, the results confirm firmly the global greenhouse effect affecting our planet, but what seems rather puzzling is the fact that this warming trend has accelerated over time resulting in a changing climate toward warmer periods, for that reason a likely shift in the region of a semi-arid to tropical or arid regime overall, depending mainly on the evolution of the Azores anticyclone.

Impact of Industrial Pollution on the Zooplankton Population Diversity of the Hammam Boughrara Dam

Works concerning zooplankton of freshwaters of the western area of Algeria are only very fragmentary and remain at an embryonic state. Remediating to this situation, it led a study of the biodiversity and zooplanktonic populations distribution in time and space in the Boughrara dam lake which remains subject to a strong pollution coming essentially from Morocco. The preliminary results of the faunistic analysis of the zooplanktonic populations enabled to highlight an important richness of zoological groups. The CFA （correspondences factorial analysis） and the AHC （ascending hierarchical classification） methods used both enabled to define the species distribution of both open waters and littoral ones, and also to perform existing affinities between them and the state of the used medium. Compared to other barrages, such as those of Bouhanifia and of Sarno, the zooplanktonic populations of both open waters and littoral populations appear to a great extent numerous in rain period. On the quantitative and qualitative level, the zooplanktonic populations strongly suffer from the pollution contamination coming from the Mouillah River especially in summer period. It is time to think about the protection of this fauna which is the second trophic chain link and this intending to preserve the ecosystems in an equilibrium state and to consider the exploitation of natural resources in the realization of an aquacultural farm.

Complex Object Shapes Recognition. Automatic Aid Photointerpretation in a Satellite Image

The interpretation of geological structures on earth observation images involves like many other domains to both visual observation as well as specialized knowledge. To help this process and make it more objective, we propose a method to extract the components of complex shapes with a geological significance. Thus, remote sensing allows the production of digital recordings reflecting the objects’ brightness measures on the soil. These recordings are often presented as images and ready to be computer automatically processed. The numerical techniques used exploit the morphology ma- thematical transformations properties. Presentation shows the operations’ sequences with tailored properties. The example shown is a portion of an anticline fraction in which the organization shows clearly oriented entities. The results are obtained by a procedure with an interest in the geological reasoning: it is the extraction of entities involved in the observed structure and the exploration of the main direction of a set of objects striking the structure. Extraction of elementary entities is made by their physical and physiognomic characteristics recognition such as reflectance, the shadow effect, size, shape or orientation. The resulting image must then be stripped frequently of many artifacts. Another sequence has been developed to minimize the noise due to the direct identification of physical measures contained in the image. Data from different spectral bands are first filtered by an operator of grayscale morphology to remove high frequency spatial components. The image then obtained in the treatment that follows is therefore more compact and closer to the needs of the geologist. The search for significant overall direction comes from interception measures sampling a rotation from 0 to 180 degrees. The results obtained show a clear geological significance of the organization of the extracted objects.