@article{VormoorHeistermannBronstertetal.2018,
  author    = {Vormoor, Klaus Josef and Heistermann, Maik and Bronstert, Axel and Lawrence, Deborah},
  title     = {Hydrological model parameter (in)stability},
  series = {Hydrological sciences journal = Journal des sciences hydrologiques},
  volume    = {63},
  journal   = {Hydrological sciences journal = Journal des sciences hydrologiques},
  number    = {7},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0262-6667},
  doi       = {10.1080/02626667.2018.1466056},
  pages     = {991 -- 1007},
  year      = {2018},
  abstract  = {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.},
  language  = {en}
}
@article{VormoorSkaugen2013,
  author    = {Vormoor, Klaus Josef and Skaugen, Thomas},
  title     = {Temporal disaggregation of daily temperature and precipitation grid data for Norway},
  series = {Journal of hydrometeorology},
  volume    = {14},
  journal   = {Journal of hydrometeorology},
  number    = {3},
  publisher = {American Meteorological Soc.},
  address   = {Boston},
  issn      = {1525-755X},
  doi       = {10.1175/JHM-D-12-0139.1},
  pages     = {989 -- 999},
  year      = {2013},
  abstract  = {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\%).},
  language  = {en}
}