{% extends base_template %} {% load static %} {% load i18n %} {% block content %}

{% trans "KOSTRA Method" %}

{% trans "Heavy rainfall index (SRI)" %}

{% trans "The present Heavy Rainfall Index (SRI) assigns various precipitation levels to a 12-stage heavy rainfall scale. The heavy rainfall index was created site-specifically for 12 different duration levels. Depending on the duration level, a given amount of precipitation leads to a different heavy rainfall index." %}

{% trans "The classification of precipitation levels into individual heavy rainfall categories is based on the method of" %} Schmitt et al. (2018). {% trans "For the heavy rainfall categories from 1 to 7, precipitation with a certain probability of recurrence is used. The precipitation amounts of the heavy rainfall categories from 8 to 12 are derived from the precipitation heights of category 7 multiplied by an increase factor that is constant for all duration levels." %}

{% trans 'In general, precipitation events in heavy rainfall categories 1 and 2 can be categorized as "normal" heavy rainfall events; events in categories 3 to 5 can be categorized as intense heavy rainfall events; events in categories 6 and 7 can be categorized as exceptional heavy rainfall events; and events in categories 8 and above can be categorized as extreme heavy rainfall events.' %}

{% trans "Data basis SRI" %}

{% trans "The assignment of precipitation heights to the heavy rainfall scale is based on area-wide available design precipitations, in each case for each of the duration levels under consideration. In this case, the design precipitation from" %} KOSTRA-DWD-2020 {% trans "was used as the base data." %} {% trans "However, as the KOSTRA-DWD-2020 data are not available for each of the duration levels or required return intervals considered in the SRI, the corresponding values were derived using the available KOSTRA extreme value & correction parameters on the ordinary KOSTRA-DWD-2020 grid and then conservatively distributed to the spatially higher-resolution grid of the SRI (~ 2km x 2km)." %}

{% trans "Event data" %}

{% trans "The heavy rainfall events listed in this web application were extracted from the" %} {% trans "radar climatology data" %} (RADKLIM) {% trans "of the German Weather Service (DWD)." %} {% trans "This data is available throughout Germany in a grid of approx. 1km x 1km. All events that occurred in the period from 2001 to 2021 were taken into account for the listing. You can find more information about the DWD's RADKLIM product " %} {% trans "here" %} .

{% trans "In order to compensate for the systematic underreporting of heavy rainfall events in the radar data compared to station measurements, the events were corrected using a statistical method. This procedure is described in" %} Hänsler & Weiler (2020) {% if LANGUAGE_CODE == 'de' %} beschrieben{% endif %}.

{% trans "In order to intersect the RADKLIM data with the coarser SRI tiles (approx. 2km x 2km), the original 5-minute data from the grid points that intersect with the respective SRI tile were averaged according to their area fraction." %}

{% trans "In general, only events that correspond to an SRI ≥ 1 are displayed. Furthermore, the maximum number of events shown was limited to 15. If fewer than 15 events with an SRI ≥ 1 were observed in the considered period, correspondingly fewer events are shown." %}

{% trans "In order to prevent the majority of the events listed from being caused by the same precipitation event (same event, but different duration level), the additional criterion that a maximum of 4 duration levels per event are shown in the table was introduced." %}

  1. Schmitt, T., Krüger, M., Pfister, A., Becker, M., Mudersbach, C., Fuchs, L., Hoppe, H., Lakes, I., 2018. Einheitliches Konzept zur Bewertung von Starkregenereignissen mittels Starkregenindex 65, 113–120. DOI:10.3242/kae2018.02.002. {% trans "Online available" %}: {% trans "here" %}
  2. Deutscher Wetterdienst (DWD), 2023. Koordinierte Starkniederschlagsregionalisierung und -auswertung des DWD (KOSTRA-DWD-2020). {% trans "Online available" %}: {% trans "here" %}
  3. Winterrath, T., Brendel, C., Hafer, M., Junghänel, T., Klameth, A., Lengfeld, K., Walawender, E., Weigl, E., Becker, A., 2018. Radar climatology (RADKLIM) version 2017.002; gridded precipitation data for Germany: Radar-based gauge-adjusted one-hour precipitation sum (RW). DOI:10.5676/DWD/RADKLIM_RW_V2017.002
  4. Hänsler, A., Weiler, M., 2022. Enhancing the usability of weather radar data for the statistical analysis of extreme precipitation events. Hydrology and Earth System Sciences 26, 5069–5084. DOI:10.5194/hess-26-5069-2022
{% endblock %} {% block scripts %} {% endblock %}