On November 25th 2015, we had the opportunity to host a lecture titled ‘Wetlands in Drylands’ by Dr Stephen Tooth in Geography Seminar Series. Dr Tooth is a Professor of Geography at Aberystwyth University. His research interests include geomorphology and sedimentology, especially in the drylands of Australia and southern Africa.
Dylan Potter, a third year undergraduate student, took the time to write a blog on the event:
I had the pleasure of attending the lecture by Dr Stephen Tooth of Aberystwyth University on Wednesday, November 25th. This lecture titled “Wetlands in Drylands” was a brief but insightful talk on the fundamentals of wetland processes within arid and semi-arid regions, in an oxymoronically pairing of two very different systems. Dr Tooth outlined how the wetlands found in these regions break the convention that is upheld by wetlands in more humid areas, despite possessing the basic characteristics. Several case studies in Southern Africa, including Dr Tooth’s own research on the Klip River in South Africa, demonstrated the nature of this rule-breaking, highlighting abnormalities such as the disappearance and reforming of channels at various intervals and the decreases in sinuosity and channel width further downstream. Some rivers in the case studies also exhibited unusual features, drawing attention to unique structures such as waterholes and salinized islands within these landscapes. Comparing humid and dryland wetlands raised questions regarding hydrological budgets, channel processes and the timescales and ages of the system. While most wetlands in humid regions formed after deglaciation and during the Holocene, wetlands in dryland were unaffected by glaciation and thus have signs of a rich history made apparent by multitudes of abandoned channels. Dr Tooth’s work with his colleagues on the Klip River found lateral migration of meander belts to be at a rate of 0.16m/yr, meaning the process which created the abandoned channels were thousands of years in the making, and interestingly had no effects on the long-term stability of the channel. Thus wetlands in drylands still prove to be a bit of an enigma. Some final remarks were then made on how these anomalies can be managed, with particular focus on the Dalai Lake Nature Reserve, where efforts were being made to prevent possible habitat destruction.
Those interested in Dr Tooth’s area of expertise should have a look at his work “10 reasons why Geomorphology is important” found at goo.gl/XHsmdY
Blog authored by: Dylan Potter. Edited and photographs by: Ankit Verma