Use-dependent erosion hazard due to water for the natural areas of Germany in 2007 (scenario with 25 % of the land area in conservation order)

The usage-dependent, average annual erosion hazard due to water for 2007 is calculated according to DIN 19708 with the general soil removal equation ABAG for arable land. For the calculation, the factors R=lowfall intensity (long-year average summer precipitation of the period 1971-2000, DWD), K= soil erodibility (k-factors of the BÜK 1000, BGR, 2005), L=hang length, S=hang slope (DGM 25, BKG, 2007) and C=fruit succession factor (as crop species groups, agricultural structure survey 2007, FDZ Nord). For the ordering method (floor processing) it is assumed as a comparative scenario that about 25 % of the total arable area of Germany is processed in conservation (non-reversing, mulch seed) ordering method. Accordingly, the scenario represents the federal states that belonged to the Federal Republic until 1990. The cross-cutting in the form of the P factor was not taken into account due to the scale and viewing space. The calculation was carried out nationwide for a mesh size of 50 meters and C factors at the level of the natural area, because data at the municipal level, depending on the structure of the company, are subject to a secret reservation and there is a risk that a uniform basis of evaluation can then be used. For this reason, mean values for the natural spatial units (BFN, as of 2008) were calculated, which are shown here. The presentation was presented only for arable land determined on the basis of the use-differentiated soil overview map for Germany (BÜK 1000 N, BGR, 2007). The methodological approach and further results are the UBA text 16/2011 (http://www.umweltbundesamt.de/publikationen/wirkungen-klimaaenderungen-auf-boeden): “Impacts of climate change on soils — Studies on the effects of climate change on soil erosion by water” Wurbs, D. and Steininger, M.本数据集针对耕地，依据德国工业标准DIN 19708（DIN 19708）与通用土壤流失方程ABAG（ABAG），计算得到2007年与土地利用相关的年均水蚀灾害风险。本次计算用到以下核心因子：R因子为降雨侵蚀力（1971-2000年多年平均夏季降水量，德国气象局（DWD, Deutscher Wetterdienst））；K因子为土壤可蚀性（BÜK 1000的k因子，联邦地质与自然资源研究所（BGR, Bundesanstalt für Geowissenschaften und Rohstoffe），2005年）；L因子为坡长；S因子为坡度（德国地形模型25（DGM 25），联邦制图与大地测量局（BKG, Bundesamt für Kartographie und Geodäsie），2007年）；C因子为作物轮作因子（按作物类群划分，基于2007年农业结构调查数据，北德研究数据中心（FDZ Nord, Forschungsdatenzentrum Nord））。针对耕作模式（floor processing），本研究设定对比情景：德国总耕地面积中约25%采用保护性耕作模式（无翻转犁作业、覆盖播种）。该情景对应1990年前属于德意志联邦共和国的各联邦州。受研究比例尺与空间范围限制，未纳入以P因子形式体现的水土保持措施项。本次计算以50米网格分辨率在全国范围内开展，C因子采用自然区域尺度数据；由于市级层面的耕地数据受经营主体结构影响存在保密限制，难以形成统一的评估基准，因此本研究计算了自然空间单元（BFN，截至2008年）的平均值并予以展示。本次展示仅涵盖基于《德国依土地利用区分的土壤概图》（BÜK 1000 N，BGR，2007年）划定的耕地范围。本研究的方法框架与进一步结果详见德国联邦环境署（UBA, Umweltbundesamt）报告16/2011：《气候变化对土壤的影响——气候变化对水蚀土壤的效应研究》（作者：Wurbs, D. 与 Steininger, M.，链接：http://www.umweltbundesamt.de/publikationen/wirkungen-klimaaenderungen-auf-boeden）。