Análisis de las crecidas presentadas en los ríos Tarqui, Yanuncay y Tomebamba desde 1997 hasta 2011

Abstract

The city of Cuenca is crossed by four rivers that occasionally overflow as consequenceof heavy rainfall, especially during the rainy season, causing human and material losses. In order to face these climate risks, studies that describe the behavior of the flow are required, allowing carrying out a proper risk management and applying this knowledge as a non-structural approach to disaster mitigation. The present study describes the hydrometeorological conditions of flow and precipitation that induced floods in Tomebamba, Yanuncay andTarqui rivers, between 1997 and 2011. Firstly, the relevance of the rainfall and discharge stations to describe the configuration of floods is analyzed, while evaluating whether the strongest floods were caused by extraordinary rainfall. Then the accumulated volume of rainfall that triggered floods isdetermined, as well as the time (in days) it took to accumulate; it is also established the dischargeabove which risk situations start. Finally, the values of precipitation and flow, together studied,are used to determine the behavior of these two parameters prior the occurrence of flooding. It has then been possible to propose flow values that involve risk; rainfall volumes accumulated a certain number of days that can cause floods, and reference slopes for the cumulative average flow vs. cumulative rainfall relationship; information that with adequate monitoring enables early warning of floods in these 3 rivers.