TY  - JOUR
A1  - Pilz, Tobias
A1  - Delgado, José Miguel Martins
A1  - Voss, Sebastian
A1  - Vormoor, Klaus Josef
A1  - Francke, Till
A1  - Cunha Costa, Alexandre
A1  - Martins, Eduardo
A1  - Bronstert, Axel
T1  - Seasonal drought prediction for semiarid northeast Brazil
BT  - what is the added value of a process-based hydrological model?
JF  - Hydrology and Earth System Sciences
N2  - The semiarid northeast of Brazil is one of the most densely populated dryland regions in the world and recurrently affected by severe droughts. Thus, reliable seasonal forecasts of streamflow and reservoir storage are of high value for water managers. Such forecasts can be generated by applying either hydrological models representing underlying processes or statistical relationships exploiting correlations among meteorological and hydrological variables. This work evaluates and compares the performances of seasonal reservoir storage forecasts derived by a process-based hydrological model and a statistical approach.

Driven by observations, both models achieve similar simulation accuracies. In a hindcast experiment, however, the accuracy of estimating regional reservoir storages was considerably lower using the process-based hydrological model, whereas the resolution and reliability of drought event predictions were similar by both approaches. Further investigations regarding the deficiencies of the process-based model revealed a significant influence of antecedent wetness conditions and a higher sensitivity of model prediction performance to rainfall forecast quality.

Within the scope of this study, the statistical model proved to be the more straightforward approach for predictions of reservoir level and drought events at regionally and monthly aggregated scales. However, for forecasts at finer scales of space and time or for the investigation of underlying processes, the costly initialisation and application of a process-based model can be worthwhile. Furthermore, the application of innovative data products, such as remote sensing data, and operational model correction methods, like data assimilation, may allow for an enhanced exploitation of the advanced capabilities of process-based hydrological models.
KW  - Water Availability
KW  - Uncertainty Processor
KW  - Forecasting Framework
KW  - Sediment Transport
KW  - Reservoir Networks
KW  - Jaguaribe Basin
KW  - Climate
KW  - Precipitation
KW  - Nordeste
KW  - Connectivity
Y1  - 2019
U6  - https://doi.org/10.5194/hess-23-1951-2019
SN  - 1027-5606
SN  - 1607-7938
VL  - 23
SP  - 1951
EP  - 1971
PB  - Copernicus Publications
CY  - Göttingen
ER  -