Validez de la técnica de intensidad instantánea para la extracción de hietogramas de diseño típicos
Fecha
2013
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Centro Universitario Rosario de Investigaciones Hidroambientales (CURIHAM). Facultad de Ciencias Exactas, Ingeniería y Agrimensura. Universidad Nacional de Rosario.
Resumen
Descripción
La ausencia de registros históricos de caudales aptos hace necesario evaluar indirectamente las crecidas de proyecto, mediante transformación de lluvias de diseño, precipitaciones críticas que hipotéticamente ocurri-rían en el futuro con determinada frecuencia. La predicción de tales lluvias incluye su distribución temporal característica o hietograma tipo. Una técnica para estimarla es extraer datos de la relación intensidad-duración-recurrencia (i-d-T) de las lluvias máximas, alternando con aumentos de duración, como el método de Intensidad Instantánea. Esta técnica produce un hietograma continuo, automáticamente compatible con la relación i-d-T pues de ella se extrae y es factible explicitarlo analíticamente, como es el caso del Modelo DIT (Caamaño Nelli y García, 1999). Los objetivos del presente trabajo son: verificar la ecuación del hietograma tipo de intensidad instantánea que produce el modelo DIT con tres parámetros (Caamaño Nelli et al., 2012), aplicarla con datos de Ceres (Santa Fe) para duraciones breves y comparar los resultados con los de métodos de síntesis (Huff, 1967; Pilgrim y Cordery, 1975). Como resultados, la ecuación del hietograma no varía con la recurrencia, la pérdida de volumen se corrige y la altura del pico se muestra mucho más verosímil. Esto respalda el procedimiento ensayado y lo hace recomendable en ausencia de hietogramas históricos.
The absence of suitable historical flow discharge records makes it necessary to evaluate design floods indi-rectly, by transforming design storm which are critical rainfall event that are likely to occur with a certain probability. The prediction of such rainfall events includes the definition of its typical temporal distribution or typical hyetograph. A technique to estimate that temporal distribution is extracting data from the rainfall intensity–duration-recurrence (i-d-T) curves through the instantaneous intensity method. This technique produces a continuous hyetograph that is automatically compatible with the use of i-d-T models from where the data is extracted such as the DIT Model (Caamaño Nelli and García, 1999). The objectives of this work are: a) to evaluate typical hyetograph distribution generated using the instantaneous intensity method implemented with the DIT model with three parameters (Caamaño Nelli et al, 2012); and b) to apply this distribution using data from Ceres (Santa Fe) for short durations and to compare the results with the typical hyetograph distribution estimated using methods proposed by Huff (1967) and Pilgrim and Cordery (1975). As a result, the hyetograph equation does not change with the recurrence, the loss of volume is corrected and the peak height is much more plausible. This supports the procedure tested and does it recommendable in the absence of historical hyetographs.
The absence of suitable historical flow discharge records makes it necessary to evaluate design floods indi-rectly, by transforming design storm which are critical rainfall event that are likely to occur with a certain probability. The prediction of such rainfall events includes the definition of its typical temporal distribution or typical hyetograph. A technique to estimate that temporal distribution is extracting data from the rainfall intensity–duration-recurrence (i-d-T) curves through the instantaneous intensity method. This technique produces a continuous hyetograph that is automatically compatible with the use of i-d-T models from where the data is extracted such as the DIT Model (Caamaño Nelli and García, 1999). The objectives of this work are: a) to evaluate typical hyetograph distribution generated using the instantaneous intensity method implemented with the DIT model with three parameters (Caamaño Nelli et al, 2012); and b) to apply this distribution using data from Ceres (Santa Fe) for short durations and to compare the results with the typical hyetograph distribution estimated using methods proposed by Huff (1967) and Pilgrim and Cordery (1975). As a result, the hyetograph equation does not change with the recurrence, the loss of volume is corrected and the peak height is much more plausible. This supports the procedure tested and does it recommendable in the absence of historical hyetographs.
Palabras clave
lluvias de diseño, hietogramas tipo, método de intensidad instantánea, modelo DIT.