Effective water balance during the main vegetation period (May-August) in Germany based on climate scenario data

The effective water balance is the difference between water supply and potential evapotranspiration during the main vegetation period (May-August). The water supply consists of the precipitation during this period, the amount of water present in the soil (described by the usable field capacity in the effective rooting zone) and possibly a capillary rise. The capillary rise is the result of the ascent rate per day and the culture-dependent duration of the ascent. The rate of ascent depends essentially on the soil texture and the distance of the lower limit of the effective rooting zone to the groundwater or backwater body. The landuse stratified soil map of Germany at scale 1:1,000,000 (BUEK1000N) was used as pedological input to the model. The landuse information was derived from CORINE land cover data set (CLC2006). The climate scenario data (https://www.dwd.de/ref-ensemble) was provided by the German Meteorological Service (DWD) in a resolution of 5 x 5 km. It contains 16 bias-corrected datasets (combination of global and regional climate models), which describe the scenario RCP8.5 (RCPs Representative Concentration Pathways) assuming an additional radiation of 8,5 W/m². The nine raster datasets with a resolution of 5 x 5 km represent the mean, the 15th and 85th percentile of the effective water balance during the main vegetation period in Germany for the climate periods 1971-2000, 2031-2060 and 2071-2099.有效水分平衡（effective water balance）指主要植被生长期（5月至8月）内水分供给与潜在蒸散量（potential evapotranspiration）之间的差值。水分供给由该时段内的降水量、土壤中留存的水量（以有效根系层（effective rooting zone）的有效田间持水量（usable field capacity）表征）以及可能存在的毛管上升水（capillary rise）组成。毛管上升水由每日上升速率与依赖于作物类型的上升持续时长共同决定，而上升速率主要取决于土壤质地，以及有效根系层下限与地下水或回水区之间的距离。本模型的土壤学输入数据采用了比例尺1:100万的德国土地利用分级土壤图（BUEK1000N），其中土地利用信息源自CORINE土地覆盖数据集（CLC2006）。气候情景数据（链接：https://www.dwd.de/ref-ensemble）由德国气象局（German Meteorological Service, DWD）提供，空间分辨率为5×5千米；该数据集包含16套经过偏差校正的数据集（由全球与区域气候模型耦合构建），用于描述典型浓度路径（Representative Concentration Pathways, RCPs）中的RCP8.5情景，该情景假设额外辐射强迫为8.5 W/m²。本数据集包含9套空间分辨率为5×5千米的栅格数据集，分别对应德国在1971-2000年、2031-2060年及2071-2099年三个气候时段内，主要植被生长期有效水分平衡的均值、15分位数与85分位数。