Climatic compound events in Bavarian counties between 1981 and 2021 during the development phases of maize and winter wheat

The dataset contains the yearly number of climatic compound events in the 96 counties of Bavaria between 1981 and 2021 in the development phases of maize and winter wheat. Compound events are defined as multiple extreme events occurring together, in this case, heat (high temperatures) and drought (low precipitation). Climatic values are considered extreme if they are higher (or lower in the case of precipitation) than certain thresholds. The thresholds were defined via the percentiles of values in the climatically more stable reference period between 1951 and 1980. The temperature and precipitation values were obtained from the weather stations run by the German Meteorological Service (DWD). For the study period 1981 – 2021, they were brought on the spatial scale of the Bavarian counties via Thiessen-Polygons. For the reference period, the values were not differentiated spatially but applied for whole Bavaria which leads to a higher number of extreme events in dryer regions. Temporally, the extreme events were differentiated for the development phases of maize and winter wheat. The percentiles were applied to the climatic values from the whole development phases (May – October for maize, November – July for winter wheat, always for the whole months), the vegetative phase (May – July for maize, November – April for winter wheat), and the reproductive phase (August – October for maize, May – July for winter wheat). To account for the water storage in the soil, in addition to the precipitation of one day, extremes of the precipitation sums of this day with the 9, 19, and 29 preceding days were calculated as well. Multiple extreme events were defined as compound events when they fall together in the same county and on the same day. These compound events were calculated in five severity levels depending on the applied percentiles (above the 95th percentile for temperature values and below the 10th percentile for precipitation as the most severe level, followed by the 90th and 20th, 85th and 30th, 80th and 40th, as well as the 75th and 50th percentile). From the daily compound events, finally, the yearly sums were built for each county. The first column of the dataset describes from how many days the precipitation sum was built, in which development phases the compound events lie, and with which severity level. For each of these 120 combinations, the values for the years 1981 – 2021 in the 96 counties are given. These values are used to examine how differently defined compound events affect the variability of maize and winter wheat yields.

Research domain: Climate data

Research question: How affect climatic compound events the variability of maize and winter wheat yields?