Study of the temporary hydrographic networks as a conditioner of the urban morphology. Case Las Grutas Beach Resort, Argentina

GENCHI, SIBILA A.; CARBONE, M. ELIZABETH; PERILLO, GERARDO M. E.; PICCOLO, M. CINTIA

Bahía Blanca, Buenos Aires, Argentina

Congreso; ECSA 44 Science and mangement of estuaries and coasts: A tale of two hemispheres; 2008

Estuarine Coastal Science Association-Instituto Argentino de Oceanografía

Las Grutas beach resort is located in the North-West coast of San Matías Gulf. The coastal area is characterized by active cliffswhich are bordered by wave-cut platform and beaches. Las Grutas is mainly intersected by two river basins with fourth-ordertemporary hydrographic networks. The purpose of this study is to analyze the increasing urbanization and its relationship with thepresence of the fluvial geoforms. Climatic variables such as precipitation and humidity were statistically processed. Urbanmorphology and geomorphologic environments were analyzed through the cadastral map of 2003, topographic charts and aephotographs corresponding to the years 1963, 1986 and 2008. The activation of the hydrographic network is caused by torrentialrainfall events greater than 40 mm, favored by its average slope between 2.44 and 1.90%. The surface runoff produces smallscarps on the beach at the mouth of both main channels. The flooding and draining of rain liquids on the streets that converge onthe courses, contributes to increase the flow and the risk of flooding. This analysis shows that temporary hydrographic networksdetermine the urban development. The sharp increase of the urbanization (61%) during the period 1986-2008 not altered the naturaldisposition of channels. However, the area adjacent to water courses is occupied by urban uses in recent years. The lack of acoastal urban management plan suited to geomorphologic environments determined that much of the buildings are located invulnerable areas