Spatiotemporal analysis of precipitation and water balance components in the Kölnbrein catchment

VERBUND Energy4Business AG applies the conceptual precipitation-runoff model COSERO as part of its operational forecasting system for inflow forecasts of reservoirs and uses the INCA product as model input data. A previous study, carried out in the high-alpine catchment of ​​the Kölnbrein reservoir, operated by Verbund, showed that precipitation as model input is often severely underestimated. In this study, therefore, a spatiotemporal analysis of the precipitation conditions in this catchment is to be carried out in order to pursue the following four goals: 1) Analysis of the solid and liquid precipitation for various spatially distributed precipitation products as well as station measurements with a temporal resolution on a monthly basis: The aim is to determine whether in certain months the precipitation deficit is larger or smaller than the annual average and how the products differ seasonally. 2) Analysis of the effect of precipitation downscaling of the INCA product, as well as consideration of the precipitation distribution for altitude bands in comparison to the area mean: This analysis aims to determine to what extent the altitude-dependent downscaling leads to an improved representation of meteorological parameters in the area and how INCA can be assessed in comparison to other precipitation datasets for different altitude levels. 3) Preparation of monthly water balances and monthly comparison of the storage inflows observed by Verbund Energy4Business and those simulated with COSERO: The aim is to better understand the water balance components in the area with a higher temporal resolution (monthly). In addition to a possible seasonal precipitation deficit in the data sets, the generation of runoff over time and storage inflows from snowmelt can thus be better understood. 4) Investigation of the exceptionally low-snow season 2021/22: This season is characterized by a pronounced snow drought situation in the winter and spring months and shows a different picture in the temporal and quantitative snow cover development as well as the water balance components. This gives potential insights about a future development of snow cover development under climate change conditions.