Erosionsatlas Hessen

Bodenerosion ist eine flächenhaft vorkommende schädliche Bodenveränderung in Hessen. In der Mittelgebirgslandschaft spielt vor allem die Wasser- und Bearbeitungserosion eine bedeutende Rolle. Größere Schäden durch Winderosion sind nur lokal und zeitlich sehr begrenzt zu beobachten. Der Bodenerosionsatlas Hessen 2018 liegt nun in der 2. Auflage vor (https://www.hlnug.de/?id=8569). Auf Grundlage des Digitalen Geländemodells mit einer Auflösung von 5m, kann der Atlas für teilschlagspezifische Bewertungen und eine Bewirtschaftungsberatung herangezogen werden. In die neue Auflage des Atlas wurden auch Grünlandflächen und Sonderkulturen mit einbezogen, um Nutzungsszenarien bspw. bei einem Umbruch des Grünlandes bewerten zu können. Grundlage der schlagspezifischen Bewertung der C-Faktoren ist eine landesweite Schlagdatei, die für Hessen quasi flächendeckend vorliegt. Der landesweite Erosionsatlas stellt neben einzelnen Erosionsfaktoren die potenzielle Bodenerosion durch Wasser nach der Allgemeinen Bodenabtragsgleichung (ABAG) für 2 Bodennutzungsszenarien (Winterweizen und Mais) sowie einer lokalen Fruchtfolgenbewertung bereit. Als fruchtfolgenrepräsentativer C-Faktor wurde der teilschlagspezifische Mittelwert der C-Faktoren für die Jahre 2011 bis 2016 verwendet. Die unterschiedlichen Nutzungsszenarien sowie schlag- bzw. feldblockorientierte Berechnung der örtlichen Hanglänge, bieten umfassende Interpretationsmöglichkeiten für die Gewässerschutz-, Bodenschutz- und Landwirtschaftsberatung

A rainfall data intercomparison dataset of RADKLIM, RADOLAN, and rain gauge data for Germany

Quantitative precipitation estimates (QPE) derived from weather radars provide spatially and temporally highly resolved rainfall data. However, they are also subject to systematic and random bias and various potential uncertainties and therefore require thorough quality checks before usage. The dataset described in this paper is a collection of precipitation statistics calculated from the hourly nationwide German RADKLIM and RADOLAN QPEs provided by the German Weather Service (Deutscher Wetterdienst (DWD)), which were combined with rainfall statistics derived from rain gauge data for intercomparison. Moreover, additional information on parameters that can potentially influence radar data quality, such as the height above sea level, information on wind energy plants and the distance to the next radar station, were included in the dataset. The resulting two point shapefiles are readable with all common GIS and constitutes a spatially highly resolved rainfall statistics geodataset for the period 2006 to 2017, which can be used for statistical rainfall analyses or for the derivation of model inputs. Furthermore, the publication of this data collection has the potential to benefit other users who intend to use precipitation data for any purpose in Germany and to identify the rainfall dataset that is best suited for their application by a straightforward comparison of three rainfall datasets without any tedious data processing and georeferencing

Groundwater recharge in Slovenia - Results of a bilateral German-Slovenian Research project

Groundwater is a resource of utmost strategic importance for Slovenia and Germany providing drinking water of good quality to its population. For decades, management of this key resource has received the highest priority of our national hydrological services. In the framework of the service activities in both countries, groundwater status in terms of quantity and quality has been observed and studied systematically for more than 50 years. In the eighties of the last century the first models forgroundwater recharge assessment at local and regional scale were developed. However, long time assessment of groundwater status and estimation of groundwater recharge for heterogeneous hydrogeology systems of entire countries were not available. In this respect the GROWA model, developed at the Agrosphere Institute of Research Centre Jülich, was one of the first groundwater recharge models that was applicable at the level of river basins and Federal States in Germany. The transfer and application of the GROWA model to groundwater systems of the Republic of Slovenia was a pioneering effort, establishing for the first time a groundwater recharge model covering the whole territory of Slovenia and not focusing on individual aquifers only, being the practice in Slovenia before. [...

Die Phosphatbelastung großer Flusseinzugsgebiete aus diffusen und punktuellen Quellen

This dissertation is embedded in the inter-disciplinary project named ”REGFLUD“ which is funded by the German Federal Ministry for Education and Research. The overall aim of the thesis is to develop and apply a GIS-based model for the analysis of P-fluxes from point and diffuse sources in macroscale river basins. For this purpose two stuy basins with varying natural conditions are chosen, i.e. the River Ems catchment (12,940 km$^{2}$) and parts of the River Rhine catchment (12,160 km$^{2}$). The new empirical phosphate model MEPhos allows the quantification of mean longterm P-inputs via drainage, groundwater-borne runoff, erosion, wash-off, rainwater sewers, combined sewers overflows, municipal sewage treatment plants and industrial effluents. Additionally the model takes into account P-retention in both running and standing waters. Diffuse P-entries to surface waters via drainage, groundwater-borne runoff, erosion and wash-off are modelled area-differentiated based on a phosphotope-approach. Phosphotopes are homogeneous sub-area types with defined properties and are used to discretize the river basin. To derive phosphotopes highly-resolved data sets are clipped in GIS. This approach enables the localization of “hot spots”, i.e. subareas with high potential for P-output. Because natural and agricultural conditions of these sub-areas are known, efficient reduction measures can be proposed. Pemissions from municipal waste water treatment plants and industrial effluents are quantified for every plant, inputs via rainwater sewers and combined sewers overflows are modelled integratively for river sub-basins. The modelled mean annual P-entries to surface waters (1995-1999) sum up to 1666 t/a for the Ems study basin and to 1574 t/a for the Rhine study basin. The relations between diffuse and point sources are 87:13 for Ems and 32:68 for Rhine. In the lowland catchment of the River Ems P-entries via the drainage pathway dominate the diffuse load (69 %). The contrasting natural conditions in the sub-catchment of the River Rhine as well as the far higher population density lead to a totally different relevance of sources. P-entries from municipal waste water treatment plants make up 41 % of the total load. Among diffuse sources erosion plays the most important role (11 %). The highest contribution to the diffuse P-load in the River Ems basin is made by the phosphotope “drained raised bogs under grassland use”. This sub-area type emits about 30 % of all diffuse entries, while it makes up only 3.5 % of the basin area. In the River Rhine sub-basin about 24 % of all diffuse P-entries originate from the phosphotope “hydraulically connected arable land with erosion potential of more than 15 t/(ha·a)“, which has an area share of only 0.7 %. Due to the combination of small area share and high share of the overall diffuse P-load efficient reduction measures should concentrate on these two phosphotopes. The validation of MEPhos modelling results against loads, estimated from measured water quality and runoff data, is performed for 58 sub-catchments. It shows good correlations between measured and modelled mean annual P-loads (1995-1999). Sustainable use of water resources creates the demand for data as a basis for decision making. The implementation of the EU-water framework directive requires river basin district management programmes. In this context MEPhos modelling results can be of use