Dr. Mathias Ritter


Dissertation Title

Boni Island – Holozäne Landschaftsdynamik und Mensch-Umwelt-Beziehung am Vierten Nil-Katarakt (Nord-Sudan)

Supervisor: Prof. Dr. Ulrich Radtke, Prof. Dr. Helmut Brückner
Advisor: Prof. Dr. Olaf Bubenzer


The Fourth Cataract of the Nile in northern Sudan was flooded by the new Hamdab reservoir in 2008. This geoscientifically and archaeologically barely explored landscape formed a unique natural setting. The presented pre-flooding case study from Boni Island shows that the tectonically induced landform fragmentation is appa¬rently the most distinctive factor for landscape formation and its human utilization in Late Holocene. For the first time a complete map in scale 1:100,000 was generated for the Fourth Cataract containing new and precise data.

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Applying differential GPS (DGPS) and 011_Kartierung Standort 49high-resolution satellite imagery (QuickBird) at representative type localities enabled a transfer of morphological features and land use types on the whole island of Boni. Phases of alternating sedimentation and accumulation processes with intercalated periods of surface stability since the Eemian are observed. Intense local fluvial activity changed into enormous siltation controlled by remote climatic influence of the Nile´s head water region and was intermittently interrupted by times of hyperarid eolian dominance.


Correlation of soil-profiles, Boni Island

Geo-archives show that landform fragmentation caused a high diversity in sedimentation and conservation of these accumulations, their erosion respectively. Since the Middle Holocene fluvial activity is restricted to the Nile valley flood plain. Detailed morphometric analyses show a lowering of the erosion base of the Nile followed by incision into older sediments forming terraces or cause a steepening of tributary wadi´s lower sections.


Mollusk finds from Boni Island (Ritter 2012)

DGPS-recorded sediments and mollusk finds in corresponding heights above the present Nile this down cutting into this previous surface. Although human presence on Boni Island since the Late Pleistocene is documented by a small number of finds, stability of the landscape surface can be assumed for a period from 1800 BC on. The state of preservation of several archaeological sites dating back at least to this time support this idea. The most important steering factors limiting agrarian land use are the occurrence of utilizable sediments and the access to periodically rising and falling Nile waters.

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Geomorphological processes on Boni Island

The high fragmentation of the landscape causes a mosaic-like pattern of closely adjoining ecologically favorable and unfavorable conditions. Human-environmental interaction is closely related to a limited set of landscape units offering adequate conditions for highly specialized forms of land use. This means that the major landscape formation on Boni Island took place prior to 1800 BC and people inhabited an environment similar to present day conditions with a similar land use potential. Outside the Nile valley hyper aridity forms the dominant factor for morphological processes and land use.



2006–2012: PhD student at Institute of Geography, University of Cologne

1996–2005: Geography, Meteorology and Geology at the University of Cologne

Diploma Thesis: The new weather station of the SFB 389 at Balat (Dakhla Oasis/Egypt)” (in German)


Field Work

 Fall 2005: Sudan, Boni Island, Fourth Nile Cataract

 Fall 2006: Sudan, Boni Island, Fourth Nile Cataract



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