Technical backdrop for the designation of nitrate-loaded areas in accordance with § 13a Fertilisation Ordinance 2020 (DüV 2020) in Brandenburg

§13a of the Fertilisation Ordinance contains, inter alia, an obligation on the Land governments to issue regulations for areas of groundwater bodies that require special measures and regulations due to nitrate pollution. These areas are presented in this technical setting and are updated in accordance with the legal requirements of DüV 2020 and AVV GEA. The basis for the technical backdrop is the provisions of the General Administrative Regulation on the designation of areas contaminated with nitrate and eutrophicated (AVV GEA) of 3 November 2020, in particular §§ 4-10. First, the groundwater measuring stations were identified where the threshold of the groundwater regulation (50 mg NO3/l) is exceeded. Based on this, geostatistical methods (§ 6 of the GEA AVV) delineate areas to which the threshold exceedances refer. For the areas thus determined, an emission-based determination of nitrogen balances is carried out on the basis of modelling results of the Thünen Institute, taking into account nitrogen supply and nitrogen removal (§ 8 of the AVV GEA). If the nitrogen balance thus determined exceeds the maximum tolerable nitrogen balance (based on modelling results of Forschungszentrum Jülich according to § 7 of the AVV GEA), the agricultural land used for the determination of high emission risk shall be classified. The result is the present landscape, which in turn forms the basis for the field block-related exclusion of the areas relevant to measures. All IACS field blocks, which are more than 50 % of their area in the specialist setting, are subject to special requirements for fertilisation.《施肥条例》（Fertilisation Ordinance）第13a条除涵盖其他规定外，要求各土地管理部门针对因硝酸盐污染需实施特殊管控措施的地下水区域制定专项监管规则。本数据集涵盖上述需管控的地下水区域，并根据DüV 2020与AVV GEA的法定要求进行更新。本数据集的编制依据为2020年11月3日发布的《硝酸盐污染与富营养化区域划定通用行政条例》（AVV GEA）中的相关条款，尤以第4至10条为核心依据。首先，筛选出地下水管控阈值（50毫克/升硝酸盐氮）超标的地下水监测站；以此为基础，采用地质统计学方法（《AVV GEA》第6条）划定硝酸盐浓度超标的对应区域。针对上述划定的区域，基于滕嫩研究所（Thünen Institute）的模拟结果，结合氮输入与氮输出情况，开展基于排放源的氮素平衡测算（《AVV GEA》第8条）。若经测算的氮素平衡值超过最大可容忍氮素平衡阈值（依据尤利希研究中心（Forschungszentrum Jülich）的模拟结果，符合《AVV GEA》第7条要求），则需对判定为高排放风险的农用地进行等级划分。上述工作形成的最终成果即为当前的管控区划成果，进而为基于地块的管控相关区域划定排除工作提供依据。所有在本技术范围内面积占比超过50%的一体化行政与控制系统（IACS）地块，均需遵守特殊施肥管控要求。