1° Congreso Argentino de ASAGAI

The Argentine Association of Geology Applied to Engineering (ASAGAI), Argentine National Group of the International Association for Engineering and the Environment (IAEG), invites you to participate in the Congress to be held on 22, 23 and 24 August 2018 in the city of San Luis, in the province of the same name.

The Association, created in 1975, organized in September 1981 the First Symposium of Geology Applied to Engineering and after the XI Symposium of Geology Applied to Engineering and the Environment, held in the Autonomous City of Buenos Aires in 2015, decided that the event organized every three years modify its name according to the hierarchy that it has reached over time.

It is a new stage that is opening up, that of the ASAGAI congresses, with the particularity that the first one will take place in the same area as the 1981 Symposium: the City of San Luis.

Geology Applied to Engineering is defined in the statute of the International Association for Engineering and the Environment (IAEG) as “the science of research, study and solution of environmental and engineering problems arising as a result of the interaction between geology and human activities and works, as well as of the prediction and development of measures to anticipate or correct geological hazards”.

Geology Applied to Engineering includes: “the definition of the geomorphology, structure, stratigraphy, lithology and aquifers of geological formations, the chemical and hydraulic properties of all materials involved in construction, resource extraction and environmental modification; the assessment of the hydrological and mechanical behaviour of soils and rocky massifs; the prediction of changes in the above properties over time; the determination of the parameters to be taken into account in the analysis of the stability of engineering works and land; the maintenance and improvement of the environmental condition of the land”.

Program

Susceptibility map of mass movements in the southern slope of Avila

The mass movements that originate on the southwestern flank of the Avila, as observed in the analysis of the risk carried out in this work, cause numerous economic losses since many neighborhoods in the area are very susceptible to this threat, in view of the urban expansion of the city that has caused many settlements

Constraints, triggers and erosive factors affecting mass movements in the mountainous south area of Ávila in Venezuela, are spatially analyzed through ArcGIS software 10.0 a synthetic methodology that performs the analysis of these factors in each movement type (rock falls, landslides, road slope and flows) and then synthesize on a single map areas with increased susceptibility.

The main cause of mass movements in this area relates to geological conditions which are reactivated by active seismicity, heavy rainfall, and artificial changes to the ground. Only in Caracas city has registered more than 500 landslides with important effects in the last 60 years.

While the study of the risk of mass movements is elaborate, (a dispersed event in space-time and with low intensity) is one of the most costly threats at a socio-economic level.

Most of the movements studied are mainly controlled by the slope and lithology, observing that most of the most frequent instabilities occur in the metamorphic rock of the San Julián and Esquistos las Brisas Complex type and in alluvial quaternary.

Slope, altitude and orientation vary depending on the type of movement. Observed for rock falls and slopes that go from 20º to 35º and altitudes from 740 m.a.s.l. to 1110 m.a.s.l. Northeast facing mostly for landslides and southeast to the southwest of rock falls.

On the other hand, for edge faults and debris flows it is very variable, with a much lower slope and altitude for flows (0 to 10º) and a higher one for landslides, with slopes of up to 40º of dip being observed. They coincide in the maximum orientation that goes from southeast to southwest and in the fact that they are movements controlled by the adjacent hydrographic networks.

It is recommended that Venezuelan authorities take a forecast of the most frequent climatic threats and keep a forecast and control of dry vs. wet periods as these are the most frequent triggers that cause mass movements. This can be done by expanding the meteorological stations since there is currently the Maiquetía airport station, whose climatic variation contrasts with that of the southern flank of Avila, and the Caracas Valley.

As far as vegetation control is concerned, a good spatial analysis is recommended to determine the current vegetation type and thus to take vegetation as a conditioning factor. It is known that from the end of 2015 to March 2016 the ENSO has hit the Ávila mountain range causing major droughts and fires, which are triggering factors for mass movements but due to a lack of spatial information could not be included in the present work.

In addition, if urban expansion were to be controlled, the most vulnerable communities could be organized and warned of the danger that exists in this study. The most susceptible neighbourhoods are Plan de Manzano, Macayapa, Blandín, Araguaney and La Cortada.

Periodic awareness campaigns and visits to such communities can maintain areas potentially susceptible to threats from movements of evicted or prevented masses depending on the level of probability.

Delimitation of the Wildland-Urban Interface and risk of fire

This work applies methods based on Geographic Information Technologies (TIG) For the cartographic definition of these spaces at different scales. The goal is to Test official and public standardized Geographic information resources (Web services, remote sensing and LIDAR images of data infrastructures)

Wildland‐Urban Interface (W‐UI) identifies areas with new territorial dynamics, forest areas bordering residential and mixed uses. The arrival of new residents from urban environment to these places, enhances the risk arising from the inevitable cultural change.

Wildfires show the problem, its control is complicated in these areas, reaching serious consequences of economic value and loss of life. The establishment of the zones (W‐UIZ) is vital in the work prevention and risk management.

Based on Geographic Information Technologies methods will be used for cartographic definition of these areas, at different scales. Resources Geographic Information, officers and public normalized will be tested (web services, remote sensing and LIDAR from Spatial Data Infrastructure (SDI), using GIS‐based free and open‐source software, in order to evaluate the advantages of its use.