ABSTRACT:

The two small research catchments Obere Brachtpe (2.6 km²; 50.989986, 7.752013) and Bohlmicke (1 km²; 51.079319, 7.892988) are located in the Rhenish Massif, a low mountain range in Germany. Both catchments have been monitored within the time period 1999 and 2009 in order to understand how the antecedent soil moisture, stratified soils (periglacial cover beds) and topography (slope form) impacted the subsurface connectivity and the subsurface stormflow generation, a dominant runoff generation process in humid mountainous catchments. Detailed physically based investigations on runoff processes were carried out and the obtained results helped to understand how the antecedent soil moisture, stratified soils (periglacial cover beds) and topography (slope form) impacted the subsurface connectivity and the subsurface stormflow generation. The gained process knowledge, which was presented in many conferences and publications, was the basis for the discussion of open questions regarding the subsurface stormflow generation within the scientific network “Subsurface Stormflow - A well-recognized but still challenging process in Catchment Hydrology”, financed by German Research Foundation. Land use in both catchments is dominated by pasture land and spruce stands and mixed forests. Mean annual temperature is approximately 9.1°C and mean annual rainfall is approximately 1250 mm, while 15-20% of the annual precipitation comes in the form of snow. The geology is characterized by sandy silty clay shale from the Lower and Middle Devonian. Loamy Cambisols derived of periglacial slope deposits complemented by Leptosols and Stagnosols are the most prominent soils in the catchment. Long-term hydrological data sets of precipitation, throughfall, discharge, groundwater levels and soil moisture (in different soil depths) in a high temporal and spatial resolution are available for further analysis of any scientific purposes.