Author(s): Rosio Ruiz; Gabriel Echavez
Linked Author(s): Gabriel Echávez
Keywords: Flood risk evaluation; Zoning models; Nazas River; Flood risk map
Abstract: Due to growth population and immigration of the people from the country to the cities, many places along the rivers have been occupied and urbanized. When a flood occurs life losses and extensive social and property damages may happen. To prevent or at least diminish this, it is necessary to have a flood risk evaluation that prevents the construction of dwellings in dangerous zones and that allows the implementation of policies and contingency plans. On the other hand, in the last decades new techniques have been developed, like: digital aerial photography, remote sensing based on satellite imagining, and better analytical and numerical models that provide us with tools with great potential that allow to feed and to calibrate zoning models in a better and a more economical way. In this work, an integral methodology of risk evaluation and zoning that takes in consideration hydrological, geomorphologic, hydraulic and sociological data is proposed. As an application and validation of the method, a stretch of 22 km of the Nazas river in the vicinity of three cities: Torreon, Gomez Palacio and Lerdo (Mexico) is studied. The results are presented as danger, vulnerability and risk maps and, among other things, shown that for peaks greater than 350 m 3 /s (5 years return period) there are urban, industrial and agricultural zones in danger of being inundated. Finally, several recommended urban growth policies and a contingency plan to reduce the flood damages is proposed. The method can be applied in other areas with similar flood problems and can be used in the elaboration of a national flood risks map.
Year: 2002