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Water erosion is the geodynamic phenomenon that most affects the city of Brazzaville (Congo). A geological engineering mapping of the city was carried out with the objective of generating a map of water erosion hazard that facilitates the territorial ordering. The methodology focused on the processing and interpretation of Landsat and Radar SRTM images. From the geological engineering survey of the city it was made the types of water erosion Map for the diagnosis of the area. Thematic maps and the total hazard map were generated through a GIS. It is concluded that the districts located to the north, northeast and northwest of the city present the highest hazard level to water erosion, associated mainly with a low vegetation cover, sandy soil poor in clay and very erodible and the mountainous relief. [ABSTRACT FROM AUTHOR]

Landslides and rock sliding occur very frequently in the mining area of Catoca, located in Angola. Therefore, a physical/mechanical and geotechnical characterization of the massif and the rock matrix was carried out adopting the landslide classifications as proposed by Hutchinson and Varnes. The safety factor was applied based on the structural weakness coefficient (λ); resulting in 0.70 in surface rocks, sandstones and intraformational sands; 0.58 in oversaturated eluvial gneiss; 0.50 in cracked gneiss and 0.47 in the ore compound of weathered, moist kimberlitic porphyric and weathered porphyric kimberlite. These results indicate the low strength of the massif and the need to reformulate the activities in the mine and the construction of more stable slopes. It could also be observed that deformation of rocks in the slopes and the cuts in the Catoca mine is conditioned by the movement of underground water within the rock massif itself. [ABSTRACT FROM AUTHOR]

The paper represents a hydrogeologic regionalization of Pinar del Río province in GIS platform. The principles of elaboration of this map propose the division of the territory starting from the automatic integration of a group of such natural variables as: physical-geographical characteristics, hydrology, geomorphology, hydrogeology and structure particularities. It is recognized the regional regularities and the common features of each hydrogeologic structure, such as: the sources of the underground waters, the recharge conditions, circulation and discharges of the horizons and aquifer complexes, hydrochemical and hydrodynamic zoning. [ABSTRACT FROM AUTHOR]

At present time almost any information, mainly graphic, is susceptible of being transmitted through a GIS, that reduces the time of transference of the information besides providing greater functionality. The article describes the generation, by means of technology GIS, of morphostructural map of Pinar del Río Province. Proposed is a methodology in four stages that make possible to divide the territory, according to the altitude position and relief genesis, in twelve basic morphostructural regions: abrasivemarine plain, accumulative marine plain, erosive marine plain, flu-vial-marine plain, fluvial plain, marshy plain, small heights, medium heights, high heights, sub mountains and small mountains. [ABSTRACT FROM AUTHOR]

Several methods for seismic risk calculation were analyzed in order to obtain the more adequate one in relation with real data and conditions, available for seismic risk determination in Bayamo city. The seismotectonic risk, which expresses the periodicity of occurrence in determined zone, is analyzed using the computer techniques and systems. [ABSTRACT FROM AUTHOR]