Johanna is a postdoctoral researcher in the Department of Chemical Engineering at the University of Cape Town focusing on dust generated by mining activities and its impact on communities and the environment. Her background is in aeolian processes and mechanisms, with her PhD completed in Environmental and Geographical Sciences, focusing on natural dust emission from desert regions in Southern Africa. She has a broad range of experience starting in private industry where she worked for SGS (Société Générale de Surveillance) in their minerals division laboratory and air quality monitoring section performing compliance testing for a variety of clients.

Her research career developed during her time at the Texas Transportation Institute (TTI) at Texas A&M University and at the Council for Scientific and Industrial Research (CSIR) in Pretoria where she was involved in several research studies on soils and materials for road construction. She also wrote and implemented the ISO17025 quality system in the Built Environment lab at the CSIR. Johanna built on her research experience by pursuing her postgraduate studies at the University of Cape Town and completed her MPhil in 2013 during which she shifted her focus to aeolian mechanisms, processes and impacts. She has developed several successful collaborations during her time at UCT, including providing expertise on the influence of soils and aeolian processes on spatial vegetative patterning as part of a research team based in Biosciences, lecturing on soils in Landscape Architecture, and facilitating the Honour’s field trip in Geology.

Current Positions

• Postdoctoral research fellow in the Department of Chemical Engineering, University of Cape Town

Previous Positions

• Candidate researcher/technician, Council for Scientific and Industrial Research (CSIR) (2 years)
• Research Laboratory Technician, Texas Transportation Institute (part of Texas A&M University system) (3 years)
• Mineral Services Technician and Chemical Trade Analyst, Société Générale de Surveillance (SGS) South Africa (5 years)

Johanna’s research interests have focused on aeolian sediment dynamics, the sources, mechanisms and controls of emission, as well as the impacts of the transport and deposition of wind-blown sediments on air quality, the environment and people. This has included assessing the methods used to study dust emission at different spatial and temporal scales and how these methods are connected from the use of satellite data at the landform-scale to electron microscopy at the grain-scale. Her current focus is on applying her aeolian expertise to the study of mine dust with emphasis on the monitoring and measurement, exposure and health effects, environmental impacts and mitigation strategies. Her research aims to advance knowledge and solutions suited to resource-limited developing countries.

von Holdt, J. R. C., Eckardt, F. D., Baddock, M. C. & Wiggs, G. F. S., 2019. Assessing landscape dust emission potential using combined ground-based measurements and remote sensing data. Journal of Geophysical Research: Earth Surface, 124.

von Holdt, J.R. and Eckardt, F.D., 2018. Dust activity and surface sediment characteristics of the dustiest river in southern Africa: the Kuiseb River, Central Namib. South African Geographical Journal, 100(1), pp.104-121.

von Holdt, J.R., Eckardt, F.D. and Wiggs, G.F.S., 2017. Landsat identifies aeolian dust emission dynamics at the landform scale. Remote Sensing of Environment, 198, pp.229-243.

Cramer, M.D., von Holdt, J.R. and Midgley, J.J., 2019. Causes of landscape mega-ripples: The kommetjies of South Africa. Geoderma, 340, pp.25-37.

Cramer, M.D., von Holdt, J.R., Uys, V.M. and Midgley, J.J., 2017. The present and likely past climatic distribution of the termite Microhodotermes viator in relation to the distribution of heuweltjies. Journal of Arid Environments, 146, pp.35-43.

Cramer, M.D., Von Holdt, J., Khomo, L. and Midgley, J.J., 2016. Evidence for aeolian origins of heuweltjies from buried gravel layers. South African Journal of Science, 112(1-2), pp.01-10.

Eckardt, F.D., Livingstone, I., Seely, M. and Von Holdt, J., 2013. The surface geology and geomorphology around Gobabeb, Namib Desert, Namibia. Geografiska Annaler: Series A, Physical Geography, 95(4), pp.271-284.