Program for Managing the Risk due to Natural and Anthropogenic Threaths in the Municipality of Pilón,
Granma Province, Cuba.
Engineers Fernando Guasch Hechavarría, Belmis Avich Durán
and Eberto Hernández Surós
National Center for Seismic Research.
Ministry of Science, Technology and the Environment, Republic of Cuba.

BACKGROUND

Pilón is located on the border of two great regional structures: The Sierra Maestra Anticlinorium and the Barlett Deep (Cobiella, et al, 1988). Tectonically, this territory is found within what is called the Pilón Block (Guasch, et al, 1992). Its limits are the Bartlett-Cayman Fault to the south and a system which separates it from Western Sierra Maestra, from the east to the west.

The seismic activity of Eastern Cuba reveals that the coastal municipality of Pilón has been the most affected area during the last 25 years, due to the occurrence of seisms of great intensity.

A detailed macro-seismic study of both earthquakes that occurred on February 19, 1976 (Imax = VIII) and on May 25, 1992 respectively (Imax = VII), states that the intensity reported in Pilón, additionally to being associated with the hypocentral distance and the earthquakes’ magnitude itself, reflected a number of local geological, tectonic, engineering and geological conditions, which decisively influenced the structural response of a number of buildings in this locality, as well as the damages produced in such buildings. (Guasch, F. et al, 1992)

As a result of this research and previous studies, a Forecast Outline for Seismic Risk was established, in order to optimize land use and utilize available construction systems.

Additionally, a number of studies were carried out within the municipality of Pilón, to determine the structural and non-structural seismic vulnerability of health, education and communication facilities. These studies were developed in the context of the National Defense Program (different authors, 1998) and were characterized by the breadth and depth of their analysis. As a result, recommendations were made in order to reduce this risk.

To date, housing has not been a focus in these studies, especially regarding prefabricated buildings, in which most people live. These houses or buildings are technically unsound, since their strengthening structures are rusty. Therefore, it is necessary to conduct a detailed study, through a number of tests, to analyze the possibility to restore and/or repair these buildings.

This locality has been affected by a series of hydro-meteorological phenomena. During the last 30 years, for instance, the occurrence of 7 tropical cyclones have been reported. Furthermore, Pilón often endures intense droughts, resulting in the declaration of a state of emergency twice during the last ten years. Taking this background into consideration, it is concluded that seisms, tropical cyclones and intense droughts represent the main natural phenomena that affect this locality.

Man has also played a relevant role, as he controls and modifies the environment. In this context, it is recognized that the environment in Pilón has been anthropized. Balance between man and the environment has been disrupted. Population growth and economic activities associated with sugar industry, cattle raising and tourism in this area, have increased the demand for water. The superficial sources and micro-dams supplying water to this area are not enough and, therefore, the extraction of underground water and saline intrusion are taking place.

In addition, the lack of appropriate infrastructure for waste management causes the pollution of streams.

Saline intrusion and pollution have had a negative impact on Pilóns quality of water. It is also obvious the high saline level of these soils, deforestation and the impact of anthropic activities on wetlands.

LEVEL OF STUDY

There exists a detailed study on this locality, as a result of a number of research projects carried out by the National Center for Seismic Research within this municipality, such as:

• A Study on the 1976 Earthquake in Pilón.
• A Study on the Southern Coast of Sierra Maestra (From Boca de Toro to Macío River, for tourist facilities). This study was carried out as a rationale for the tourist development of this region (it also constituted a basic element for land ordering).
• An Integral Study on the 1992 Earthquake in Cabo Cruz.
• The Status of Engineering and Geological Conditions of the locality of Pilón, regarding the structural response of buildings. (It was due to this study that the Seismic Risk Map was outlined in Pilón). A number of recommendations were made regarding zones, associated phenomena and construction systems to be used in each of these zones.
• A Study on the Seismic Vulnerability of Health, Education and Communication Facilities in the Municipality of Pilón.
• A Technical Report published by the NIHR on Hydric and Geological Features in the Municipality of Pilón.

Although these studies are available, there exists no strategy to integrate all those actions aimed at reducing the impact of extreme natural phenomena on the environment. Instead of emphasizing in the history and hypothesis of damages, our study focuses on an Action Program for Appropriate Risk Management, which would allow for developing and improving the quality of life of Pilón’s inhabitants.

General goal of this program:

The preparation of an Integral Diagnosis of Natural and Anthropogenic Threats within the Municipality of Pilón, that allows for the establishment of a Sustainable Development Strategy to reduce the loss of human lives, material damages, and economic and social problems, as well as to increase the quality of life and the safety of its inhabitants, This will also increase the community work carried out by the rural population of Sierra Mestra, who face the risk of isolation in case of a disaster.

Specific goals of this program:

• Carry out a number of studies on specific settings and on damage hypotheses in the face of those natural threats already identified. This will be achieved through the completion and standardization of the level of study.
• Develop studies on how anthropized the environment is.
• Determine the influence of water (as a natural resource) on the quality of life of the population, as well as on environmental deterioration, as a result of saline intrusion and pollution.
• Establish a Strategy to manage the risks identified, through actions for restoring those factors related to vulnerability. This, in order to guarantee sustainable development within this municipality.
• Contribute to consolidating a culture of community prevention and mitigation, through the joint identification of threats, the recovery of our historic memory and the identification of factors related to vulnerability in our community.

Outcomes

• An integral environmental diagnosis of the municipality of Pilón, by using Geographic Information Systems (GIS).
• A project aimed at restoring a representative sample of housing in the locality of Pilón, especially those educational facilities affected by previous seisms. This project would be carried out with community participation.
• A project for restoring the underground basin used for water supply.
• The establishment of a Plan for Land Ordering that includes natural and anthropogenic hazards, as well as the appropriate use of natural resources and physical planning. In a similar manner, develop a Plan for Risk Management in the municipality of Pilón.
• Increase the capacity of a Project for Community Education to respond adequately, especially regarding risk management.

Fore more information, Please contact:
CENAIS, Fernando Guasch guasch@cenais.ciges.inf.cu

BIBLIOGRAPHY:

• Alvarez, et al, 1984. Informe Científico-Técnico sobre el terremoto de Pilón, del 19 de Febrero de 1976 y sus efectos.
• Avich, et al, 1993. Informe Científico-Técnico sobre la valoración ingenieril del terremoto de Cabo Cruz del 25 de Mayo de 1992 en Cuba Oriental
• Cardona A., O. M. (1988). Enfoque Metodológico para la evaluación de la amenaza, la vulnerabilidad y el riesgo sísmico
• Colectivo de autores, (1998) Informe Científico-Técnico Proyecto Granma. Programa Nacional de la Defensa. Fondos del CENAIS
• Cobiella, et al, (1988) Algunos rasgos de la geología de Cuba Oriental. Revista Ciencia y Técnica. ISPJAE.
• CONCE-CEN Norma Sismorresistente Cubana
• Guasch F., Arango E., Avich B., Chuy. T, (1992): Investigaciones Sismológicas Complejas para la región turística del Litoral Sur de la Sierra Maestra. Municipio Pilón. Provincia Granma. Informe Científico-Técnico. Fondos del CENAIS-CITMA.
• Guasch F., Avich B., Arango E., (1993). Influencia de las condiciones ingeniero-geológicas de la localidad de Pilón en la respuesta estructural de las edificaciones. Revista Geología y Minería. ISSN 0258 5979, pp 39-44.
• Chuy T., Álvarez L. (1995) Mapa de Peligrosidad Sísmica de Cuba con fines de la Norma Sismorresistente Cubana. Reporte de Investigación.
• Fondos del CENAIS y del X Fórum de Ciencia y Técnica.
• DIRND (1993) STOP DISASTERS (pp. 1-26).