Michael Gebel

• PhD
• Manager at VisDat geodatentechnologie GmbH

For particle-bound substances such as phosphorus, erosion is an important input pathway to surface waters. Therefore, knowledge of soil erosion by water and sediment inputs to water bodies at high spatial resolution is essential to derive mitigation measures at the regional scale. Models are used to calculate soil erosion and associated sediment in...

Changes in land-use, agricultural management and climate affect the turnover and storage of organic carbon in soils (SOC) as well as the nitrogen mobilization from soil organic matter (SOM), with potential side effects on nitrogen availability and leaching. When addressing the requests for increased carbon storage in soil as well as for the reducti...

The paper presents an improved approach for investigating submarine groundwater discharge (SGD) based on radon mapping and radon mass balancing in the coastal sea. While the use of radon as an environmental tracer in SGD studies is well-established, we identified based on our longstanding experience six methodical shortcomings of the conventional a...

Since the 1990’s, the groundwater quality along the southern coast of the Western Cape Province of South Africa has been affected by increasing land use activities. Groundwater resources have become increasingly important in terms of providing good quality water. Polluted coastal groundwater as a source of submarine groundwater discharge also affec...

The inclusion of biogas production into the agricultural system has modified crop management and as a result the soil organic carbon (SOC) cycle of the agricultural landscape. To evaluate the effects for the German federal state of Saxony this study determines: (1) the share of agricultural land required for biogas production, (2) the change in reg...

A major challenge for water resource management in Western Cape, South Africa, is the reduction of the growing sediment and nutrient loads in coastal areas, which belong to the areas most affected by land use change. We used the WebGIS based software STOFFBILANZ to simulate runoff, soil loss, sediment, phosphorus, and nitrogen input in the surface...

Die Veröffentlichung dokumentiert die Entwicklung eines Modellwerkzeuges zur dynamischen Bilanzierung von Humushaushalt und Nährstoffaustrag auf der mittleren Maßstabsebene. Dazu wurde eine Kopplung der praxiserprobten Teilmodelle CCB (Kohlenstoffhaushalt) und STOFFBILANZ (Nährstoffhaushalt) realisiert und erfolgreich getestet. Die Veröffentlichung...

The Miyun reservoir, located approximately 100 km North-East of the Beijing municipality, is one of the main surface water supply sources for the 20 million people living in this metropolitan area. For a variety of anthropogenic and natural reasons the Miyun reservoir suffers from increasing water quantity and quality problems. Over the past 20 yea...

Introduction Changes in land use and agricultural management have caused a strong increase in sediment and particulate phosphorus input into the Miyun reservoir. The simulation of the relevant runoff and sediment fluxes at the mesoscale needs adequate procedures, adapted to a semiarid monsoon climate and regional land-use pattern. Results The modi...

Change of land use and agricultural management, combined with severe droughts during the last two decades, are the main reasons for a strong decrease of water quality and quantity in the Miyun reservoir (China). Due to semi-arid monsoon climate, episodic water fluxes have to be considered adequately in an integrated water resources management in th...

The production of energy crops in Germany is a growing agronomic sector and is expected to occupy a substantial share of farmland in the near future. At the same time, there are concerns that energy crops might cause increased nitrogen pollution of soil water, surface water and groundwater. Therefore, the Federal State of Saxony, Germany, funded a...

From 2005 to 2009 we modelled the input of nitrogen and phosphorus in waters in the area of the Federal State of Saxony (Germany). The model results are an important component in elucidating the present situation of nutrient loads in groundwater and surface water as well as its future development. The present contribution focuses on the modelling o...

In order to derive measures to reduce nutrient loadings into waters in Saxony, we calculated nitrogen inputs with the model STOFFBILANZ on the regional scale. Thereby we have to compare our modelling results to measured loadings at the river basin outlets, considering long term nutrient retention in surface waters. The most important mechanism of n...

A multi-compartment model is applied at the mesoscale to simulate the spatially differentiated nitrate pollution of rivers by groundwater in a test area of 800 km2 in the northern part of Saxony. Both nitrate influx and discharge processes are considered. Mass transport is represented by applying a multiple flow direction algorithm to the groundwat...

Mit dem Modell STOFFBILANZ wurden die Stickstoff-, Phosphor- und Sedimenteinträge in die Gewässer im Freistaat Sachsen quantifiziert. Die Ergebnisse enthält der Nährstoffatlas Sachsen. Daraus wurden regionale Bewirtschaftungsziele abgeleitet und eine Gebietskulisse „Wasserrahmenrichtlinie/ Hochwasserschutz“ zur Förderung von Agrarumweltmaßnahmen im...

The input of nitrogen, phosphor and sediments in the waters of Saxony was quantified with the model Stoffbilanz. The results are compiled in the nutrient map Saxony. Regional management objectives were drawn from these results and the special area of conservation "Water Framework Directive/Flood protection" for the promotion of agricultural environ...

Die EU-Wasserrahmenrichtlinie (WRRL) verlangt bis zum Jahr 2009 die Erarbeitung von Bewirtschaftungsplänen nach Flusseinzugsgebieten und das Erstellen von Maßnahmenprogrammen für Wasserkörper, die die Ziele der Richtlinie bis 2015 wahrscheinlich nicht erreichen. Bei der Bestandsaufnahme der WRRL wurden Grundwasserkörper ausgewiesen und deren Belast...

Using the N-BILANZ model it is possible to quantify diffuse and point-related nitrogen deposits in medium scale river catchment areas. The present version is designed particularly for larger areas of both lowlands and hilly terrain with predominantly agricultural land use. The results of the model reflect the in- and output situation as well as tur...