Per la serie di seminari in meteorologia ambientale dell’Università di Trento, giovedì 9 maggio 2024 alle ore 17:30, Paolo Reggiani, del Department of Civil Engineering, Research Institute for Water and
Environment dell’Università di Siegen (Germania), terrà un seminario dal titolo: A retrospective hydrological uncertainty analysis using precipitation estimation ensembles for the poorly gauged Upper Brahmaputra Basin.
Il seminario si terrà in presenza nell’aula 1P (primo piano) del DICAM – Università di Trento, in via Masiano 77, e sarà possibile seguirlo in streaming su Zoom attraverso il seguente link:
https://unitn.zoom.us/j/83986532497
Meeting ID: 8398653 2497, Passcode: 708707
Abstract
We study the impact of uncertain precipitation estimates on simulated
streamflows for the poorly gauged Chinese Upper Brahmaputra Basin (UBB)
in High Mountain Asia. The process-based hydrological model TOPKAPI at
0.5 km resolution is driven by an ensemble of precipitation estimation
products (PEPs), including analyzed ground observations, high-resolution
precipitation estimates, climate data records and reanalyses over the
2008-2015 control period. The model is then forced retrospectively from
1983 onward to obtain seamless discharge estimates till 2007, a period
for which there is very sparse flow data coverage in this part of the
basin. Whereas temperature forcing is considered deterministic,
precipitation is sampled from the predictive distribution, which is
obtained through processing PEPs by means of a probabilistic processor
of uncertainty. The employed Bayesian processor combines the PEPs and
outputs the predictive densities of daily precipitation depth
accumulation as well as the probability of precipitation occurrence,
from which random precipitation fields to force the hydrological model
are sampled. The predictive density of precipitation is conditional on
the precipitation estimation predictors that are bias-corrected and
variance adjusted. For the UBB, discharges simulated from reanalysis and
climate data records score lowest against observations at three flow
gauging points, whereas high-resolution satellite estimates perform
better,
but are still outperformed by precipitation fields obtained from
analyzed observed precipitation and merged products, which we corrected
against ground observations.
The methodology employed in this hydrological study indicates how
missing flows for poorly gauged sites can be successfully retrieved. The
method can be further extended for hydrological projections of climate.
Bio
Paolo Reggiani holds the Chair of Water Resources Management and Climate
Impact Research at the University of Siegen, Germany. He graduated at
the University of Trento, Italy, in 1994 in Environmental Engineering
with a Masters in Engineering. In 2000 he was awarded a Ph.D. with
‘Distinction’ in Environmental Engineering from the University of
Western Australia. Between 1999 and 2000 P. Reggiani worked at CSIRO
Land and Water in Floreat Park, WA, where he developed modeling
approaches to assess dryland salinity in Australia. After his return to
Europe in late 2000 he participated as “Marie Curie Fellow” at the
soil science lab “Laboratoire des Transferts en Hydrologie et
Environnement” (LTHE) in Grenoble, France. In 2002 he took up an
appointment as researcher and scientific consultant at the Institute
Deltares in Delft, The Netherlands. In 2014 he was appointed Full
Professor at the University of Siegen. During his career, P. Reggiani
worked in various applied scientific and consulting projects in Asia,
Africa and Europe. An important focal point of his scientific work has
been the interface between numerical weather prediction and hydrological
forecasting, including the area of forecasting uncertainty, as well as
operational water management in data-poor areas. P. Reggiani has
published more than 60 papers in different areas of hydrology, climate
change impacts on water resources, flood forecasting, channel hydraulics
and soil science. He also acted as coordinator for several projects,
among which the FP5 project “European Flood Forecasting System
(EFFS)”. P. Reggiani partakes in several scientific boards on water
resources issues. He frequently acts as expert reviewer for scientific
evaluations in the fields of catchment hydrology, flood forecasting,
climate change impacts and natural hazard risk assessment. He is Member
of the Hydrological Services Commission at the WMO (SERCOM-HYD).