On the Use of Satellite Rainfall Data to Design a Dam in an Ungauged Site

Claudia Bertini,Francesco Napolitano,Elena Ridolfi,Luca Buonora,Fabio Russo

doi:10.3390/w12113028

Claudia Bertini, Francesco Napolitano + Show 3 more

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https://doi.org/10.3390/w12113028

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Abstract

The estimation of the design peak discharge is crucial for the hydrological design of hydraulic structures. A commonly used approach is to estimate the design storm through the intensity–duration–area–frequency (IDAF) curves and then use it to generate the design discharge through a hydrological model. In ungauged areas, IDAF curves and design discharges are derived throughout regionalization studies, if any exist for the area of interest, or from using the hydrological information of the closest and most similar gauged place. However, many regions around the globe remain ungauged or are very poorly gauged. In this regard, a unique opportunity is provided by satellite precipitation products developed and improved in the last decades. In this paper, we show weaknesses and potentials of satellite data and, for the first time, we evaluate their applicability for design purposes. We employ CMORPH—Climate Prediction Center MORPHing technique satellite precipitation estimates to build IDAF curves and derive the design peak discharges for the Pietrarossa dam catchment in southern Italy. Results are compared with the corresponding one provided by a regionalization study, i.e., VAPI—VAlutazione delle Piene in Italia project, usually used in Italy in ungauged areas. Results show that CMORPH performed well for the estimation of low duration and small return periods storm events, while for high return period storms, further research is still needed.

Highlights

Peak flow estimation is of pivotal importance for the hydrological design of hydraulic structures.An incorrect evaluation can lead to the failure of the structures themselves
The methodology can be summarized in three macro-steps: first, we compare the goodness of satellite observations against the ground-based ones by computing several continuous and categorical evaluation indexes; second, we evaluate the design storm for different return periods, using intensity–duration–area–frequency (IDAF) curves built both with satellite observations and the parameters provided by a previous regionalization study, i.e., VAPI—VAlutazione delle Piene in Italia project [31]; last, we compute the design flood peak for the catchment and we determine the spillway dimensions as an applicative example
We use Center MORPHing (CMORPH) rainfall estimates to derive design peak flows for different return periods and we compare them with the corresponding quantities computed from the VAPI regionalization project, used in ungauged areas in Italy

Summary

Introduction

Peak flow estimation is of pivotal importance for the hydrological design of hydraulic structures.An incorrect evaluation can lead to the failure of the structures themselves. In the case of dams, the peak discharge is needed both for the design and for the evaluation of hydrologic safety of the structures. Due to the frequent lack of flow observations and thanks to the development of hydrometeorological models, the focus has moved on the estimation of the design storm, which is the one that gives rise to the design flood on the catchment [7]. Following this kind of approach, once the design storm is defined, a hydrological model is applied to estimate the corresponding peak flow. One of the most common approaches adopted is the event-based one, with the design storm being associated to a certain return period

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