Physical Geography and Earth Systems Science

Our research focuses on the interaction between spheres, specifically the impact of environmental change on surface processes, ecohydrology and geochemical cycles and their consequences for environmental services. Conceptually, we transfer the analytical concepts of Earth System Sciences into smaller domains to study the impact of both natural and man-made environmental change on landscape systems. Our approach combines monitoring and experiments with GIS, remote sensing and environmental modelling. Based on an understanding of the functioning of a landscape system, this combination enables the identification of the spatial extent and relevance of a particular combination of landscape properties and reaction to change.

 

Interaction of surface processes and vegetation at the foot of the Eiger North Face (left): in a mountainous environment the presence or absence of soil as well as disturbances (natural and man-made) determine the distribution of trees. On such regional scale climate change has therefore only a limited impact. The change of tree and forest cover between 1898 and 2008 (right) shows hardly any reaction to warming, but mostly to land use change. (Source: www.geogr-helv.net/67/15/2012/gh-67-15-2012.pdf)

Interaction between humans, Vegetation and watercourses: the invasive species impatiens glandulira outcompetes native woody plants along watercourses in Europe, leaving soils near the river banks unprotected. As a consequence, erosion increases by an order of magnitude, changing river ecology and channel geomorphology.

Project: Impatiens glandulifera and its influence on the ecohydromorphic functioning of inland watercourses

Our general research interests fall into three categories of projects

Surface processes and geochemical cycles

Soil erosion is a part of Earth’s geochemical cycles. Land use change by humans has accelerated erosion and thus affected geochemical cycles. Our research combines the study of soil erosion and the Carbon and Phosphorous cycles. Experimental work on the movement and deposition of sediment and the subsequent fate of the eroded substances is linked to field sampling and monitoring as well as GIS-based extrapolation of those results to larger, slope to global scales.

Erosion, transport and deposition of soil. The redistribution of soil affects spatial patterns of carbon and nutrient stocks across a landscape and their interaction with vegetation, hydrosphere and climate.


Projects:
Movement and Fate of eroded soil organic matter in small catchments
Interill Carbon in the global Carbon Cycle
Phosphorous erosion potential of rivers banks in Denmark
Biochar erosion in Denmark

Use of a modified Griffith tube for the frachtionation of sediment.
https://www.youtube.com/watch?v=ZLHRSFvK9Uw

Land use change in southern Africa

Southern Africa is both ecologically as well as economically and politically one of the most diverse and dynamic regions on planet Earth. This renders the region as one oft he most interesting to study human-environment interaction, but offers also the opportunity to make a contribution to the sustainable development both of the region, but also on a global scale by protecting biodiversity and fostering livelihoods to maintain political stability. Our research focuses on land use in communal land in northern Namibia and the establishment of nature conservancies in the South African Karoo highlands on private land.

Small-scale farming in Northern Namibia is 
seen as an economic dead end by many farmers, but is subject to a development effort by governments, NGOs and multinational agro-business who consider increased production as a way to both improve livelihoods locally and increase food security globally.

Projects:
Potential of Payment for Environmental Services to Develop Small-Scale Farmers
Communal land reform in Namibia - Implications of Individualisation of land tenure
Land Degradation and Carbon Storage in the Karoo region of South Africa
Deforestation and land degradation in north eastern Namibia

Experimental Geosciences

A particular highlight of the environmental research in Basel is the development and application of innovative experiments to study surface processes in a wide range of environments. Our experiments aim at identifying system interactions requiring a better understanding in future climate or land use, or because exploration has just opened up new frontiers to be studied, such as the surface of Mars.   

 

Wind affects the kinetic energy of falling raindrops. Under constant climatic conditions, ignoring the effect of varying wind simply reduces the quality of model outputs by a given margin. Changing climate, and thus wind-driven rain, on the other hand, potentially has unknown effects on runoff, erosion and sediment quality.

Video of Sediment Transport by Rain Impacted Flow

Project:
Relevance and physics of wind-driven rainfall erosion