TY  - JOUR
A1  - Vormoor, Klaus Josef
A1  - Heistermann, Maik
A1  - Bronstert, Axel
A1  - Lawrence, Deborah
T1  - Hydrological model parameter (in)stability
BT  - "crash testing" the HBV model under contrasting flood seasonality conditions
JF  - Hydrological sciences journal = Journal des sciences hydrologiques
N2  - This paper investigates the transferability of calibrated HBV model parameters under stable and contrasting conditions in terms of flood seasonality and flood generating processes (FGP) in five Norwegian catchments with mixed snowmelt/rainfall regimes. We apply a series of generalized (differential) split-sample tests using a 6-year moving window over (i) the entire runoff observation periods, and (ii) two subsets of runoff observations distinguished by the seasonal occurrence of annual maximum floods during either spring or autumn. The results indicate a general model performance loss due to the transfer of calibrated parameters to independent validation periods of -5 to -17%, on average. However, there is no indication that contrasting flood seasonality exacerbates performance losses, which contradicts the assumption that optimized parameter sets for snowmelt-dominated floods (during spring) perform particularly poorly on validation periods with rainfall-dominated floods (during autumn) and vice versa.
KW  - hydrological modelling
KW  - flood seasonality
KW  - differential split-sample test
KW  - flood generating processes
KW  - Nordic catchments
Y1  - 2018
U6  - https://doi.org/10.1080/02626667.2018.1466056
SN  - 0262-6667
SN  - 2150-3435
VL  - 63
IS  - 7
SP  - 991
EP  - 1007
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Vormoor, Klaus Josef
A1  - Skaugen, Thomas
T1  - Temporal disaggregation of daily temperature and precipitation grid data for Norway
JF  - Journal of hydrometeorology
N2  - This paper presents a simple approach for the temporal disaggregation from daily to 3-hourly observed gridded temperature and precipitation (1 x 1km(2)) on the national scale. The intended use of the disaggregated 3-hourly data is to recalibrate the hydrological model currently used by the Norwegian Water Resources and Energy Directorate (NVE) for daily flood forecasting. By adapting the hydrological model to a 3-hourly temporal scale, the flood forecasting can benefit from available meteorological forecasts with finer temporal resolution and can better represent critical events of short duration and at small spatial scales. By consulting the temporal patterns of a High-Resolution Limited-Area Model (HIRLAM) hindcast series for northern Europe with an hourly temporal and a 0.1 degrees spatial resolution, existing daily 1 x 1km(2) grids for temperature and precipitation covering all of Norway (the seNorge data) were disaggregated into 3-hourly values for the time period September 1957 to December 2010. For the period 2000-05, the disaggregated 3-hourly temperature and precipitation data are validated against observed values from five meteorological stations and against 3-hourly data from the HIRLAM hindcast and daily seNorge data simply split into eight fractions. The results show that the disaggregated data perform best with anomaly correlation coefficients between 0.89 and 0.92 for temperature. With regard to precipitation, the disaggregated data also provide the highest correlations and the lowest errors. In addition, the disaggregated data prove to be best in estimating intervals without precipitation and tend to be most appropriate in estimating extreme precipitation with low occurrence probability (<20%).
Y1  - 2013
U6  - https://doi.org/10.1175/JHM-D-12-0139.1
SN  - 1525-755X
VL  - 14
IS  - 3
SP  - 989
EP  - 999
PB  - American Meteorological Soc.
CY  - Boston
ER  -