Fall 2019 Office Hours:
Wednesday & Tuesday 10-11am
I am dedicated to the application of earth observation and geospatial sciences to improve society’s understanding of and adaptation to global change. My research focuses on deriving geospatial insight from large volumes of diverse satellite data. Earth observation represents a synergy between my two great passions for environmental science and space technology.
After completing my PhD in Geographical Sciences at the University of Maryland (on a NASA Earth System Sciences Fellowship) and postdoc at NASA Goddard, I returned to my native South Africa to lead the Remote Sensing Research Unit within the Council for Scientific and Industrial Research (CSIR), CSIR-Meraka Institute for Information and Communication Technology. As Chief Scientist, I have been involved in multi-disciplinary remote sensing projects in the following application areas: fire (active, burned area and fire danger modelling), modelling carbon stocks and fluxes at country level, above ground biomass estimation, carbon cycle modelling, quantifying ecosystem services, savanna ecology, communal resource management, land degradation, human settlement monitoring, land use and land cover change.
I believe scientific leaders have to reimagine the future instead of trying to predict the future from the confines of current paradigms. We need to envision a future where socio-economic prosperity is decoupled from environmental degradation.
- Time series analysis of optical and SAR satellite data
- Terrestrial ecosystem process modelling
- Natural Resource and human settlement monitoring
- Biomass estimation with LiDAR and SAR
- Mograbi, P.J., Witkowski, E.T.F., Erasmus , B.F.N., Asner, G.P., Fisher, J.T., Mathieu, R., Wessels, K.J. (2018). Fuelwood extraction intensity drives compensatory regrowth in African savanna communal lands. Land Degradation and Development. DOI: 10.1002/ldr.3210
- Mahlangu, P., Mathieu, R.,Wessels, K., Naidoo, L.,Verstraete, M., Asner, G., Main R. (2018) Indirect Estimation of Structural Parameters in South African Forests Using MISR-HR and LiDAR Remote Sensing Data. Remote Sensing. 10: 1537. https://doi.org/10.3390/rs10101537
- Wessels, K., van den Bergh, K., Roy, D., Salmon, B., Steenkamp, K., McAlister, B., Swanepoel, D., Jewitt, D. (2016). Rapid land cover map updates using change detection and robust Random Forest classifiers. Remote Sensing. 8, 888; doi:10.3390/rs8110888
- Mograbi, P.J., Asner, G.P., Witkowski, E.T.F., Erasmus, B.F.N., Wessels, K.J., Mathieu, R., Vaughn, N. (2017) Humans and elephants as treefall drivers in African savannas. Ecography 40: 001–011, 2017
- Main, R., Mathieu, R., Kleynhans W., Wessels, K., Naidoo, L., Asner G. (2016) Hyper-Temporal C-Band SAR for Baseline Woody Structural Assessments in Deciduous Savannas. Remote Sensing. 2016, 8, 661; doi:10.3390/rs8080661
- Naidoo, L., Mathieu, R., Main, R., Wessels, K., Asner, G.P. (2016). L-band Synthetic Aperture Radar imagery performs better than optical datasets at retrieving woody fractional cover in deciduous, dry savannahs. International Journal of Applied Earth Observation and Geoinformation. 52, pp 54-64.
- Fisher, J.T., Witkowski, E.T., Erasmus, B.F., Mograbi, P.J., Asner, G.P., Aardt, J.A., Wessels, K.J., & Mathieu, R. (2015). What lies beneath: detecting sub-canopy changes in savanna woodlands using a three-dimensional classification method. Applied Vegetation Science, doi: 10.1111/avsc.12160
- Kleynhans, W., Salmon, B., Wessels, K., & Olivier, J. (2015). Rapid detection of new and expanding human settlements in the Limpopo province of South Africa using a spatio-temporal change detection method. International Journal of Applied Earth Observation and Geoinformation, 40, 74-80
- Mograbi, P.J., Erasmus, B.F., Witkowski, E., Asner, G.P., Wessels, K.J., Mathieu, R., Knapp, D.E., Martin, R.E., & Main, R. (2015). Biomass Increases Go under Cover: Woody Vegetation Dynamics in South African Rangelands. PLOS One, DOI:10.1371/journal.pone.0127093
- Naidoo, L., Mathieu, R., Main, R., Kleynhans, W., Wessels, K., Asner, G., & Leblon, B. (2015). Savannah woody structure modelling and mapping using multi-frequency (X-, C-and L-band) Synthetic Aperture Radar data. ISPRS Journal of Photogrammetry and Remote Sensing, 105, 234-250
- Fisher, J.T., Erasmus, B.F., Witkowski, E.T., Aardt, J., Wessels, K.J., & Asner, G.P. (2014b). Savanna woody vegetation classification–now in 3D. Applied Vegetation Science, 17, 172-184
- Tsela, P., Wessels, K., Botai, J., Archibald, S., Swanepoel, D., Steenkamp, K., & Frost, P. (2014). Validation of the two standard MODIS satellite burned-area products and an empirically-derived merged product in South Africa. Remote Sensing, 6, 1275-1293
- Salmon, B.P., Kleynhans, W., van den Bergh, F., Olivier, J.C., Grobler, T.L., & Wessels, K.J. (2013). Land cover change detection using the internal covariance matrix of the extended Kalman filter over multiple spectral bands. Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of, 6, 1079-1085
- Mathieu, R., Naidoo, L., Cho, M.A., Leblon, B., Main, R., Wessels, K., Asner, G.P., Buckley, J., Van Aardt, J., & Erasmus, B.F. (2013). Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multi-temporal polarimetric RADARSAT-2 fine beam images. Remote Sensing of Environment, 138, 215-231
- Wessels K.J., Colgan M.S., Erasmus B.F.N., Asner G.P., Twine W.C., Mathieu R., van Aardt J.A.N., Fisher J.T. and Smit I.P.J. (2013) Unsustainable fuelwood extraction from South African savannas. Environmental Research Letters 8: 014007
- Wessel, K.J., Van Den Bergh F., Scholes R.J. (2012) Limits to detectability of land degradation by trend analysis of vegetation index data. Remote Sensing of Environment. 125: 10-22