Intensity–duration–frequency curves from remote sensing rainfall estimates: comparing satellite and weather radar over the eastern Mediterranean
Intensity–duration–frequency (IDF) curves are widely used to quantify the probability of occurrence of rainfall extremes. The usual rain gauge-based approach provides accurate curves for a specific location, but uncertainties arise when ungauged regions are examined or catchment-scale information is...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-05-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/21/2389/2017/hess-21-2389-2017.pdf |
| Summary: | Intensity–duration–frequency (IDF) curves are widely used to quantify the
probability of occurrence of rainfall extremes. The usual rain gauge-based
approach provides accurate curves for a specific location, but uncertainties
arise when ungauged regions are examined or catchment-scale information is
required. Remote sensing rainfall records, e.g. from weather radars and
satellites, are recently becoming available, providing high-resolution
estimates at regional or even global scales; their uncertainty and
implications on water resources applications urge to be investigated. This
study compares IDF curves from radar and satellite (CMORPH) estimates over
the eastern Mediterranean (covering Mediterranean, semiarid, and arid
climates) and quantifies the uncertainty related to their limited record on
varying climates. We show that radar identifies thicker-tailed distributions
than satellite, in particular for short durations, and that the tail of the
distributions depends on the spatial and temporal aggregation scales. The
spatial correlation between radar IDF and satellite IDF is as high as 0.7 for
2–5-year return period and decreases with longer return periods, especially
for short durations. The uncertainty related to the use of short records is
important when the record length is comparable to the return period
( ∼ 50, ∼ 100, and ∼ 150 % for Mediterranean, semiarid,
and arid climates, respectively). The agreement between IDF curves derived
from different sensors on Mediterranean and, to a good extent, semiarid
climates, demonstrates the potential of remote sensing datasets and instils
confidence on their quantitative use for ungauged areas of the Earth. |
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| ISSN: | 1027-5606 1607-7938 |