Konrad Wessels

Education

• 2005-2006: Postdoc / Research Associate, NASA Goddard Space Flight Center, Hydrospheric and Biospheric Sciences Laboratory, Greenbelt, MD and University of Maryland - Baltimore County (UMBC), MD.
• 2001-2005: PhD University of Maryland (UMD), Department of Geography. Thesis title: Monitoring land degradation in Southern Africa by assessing changes in Primary Productivity. Supervisor: Prof. Stephen D. Prince.
• 1995-97: MSc Cum Laude, University of Pretoria, South Africa (UP) , Conservation Biology / Landscape Ecology, Department of Zoology. Thesis title: Biodiversity assessment and conservation planning: the gradsect survey method and the use of local scale surrogate information. Supervisor: Prof. A.S. Van Jaarsveld
• 1993: BSc Honours, Department Zoology (UP)  
• 1990-92: BSc (UP)

Positions and Appointments

• 2006 (Aug.) to present: Principal Researcher and Research Group Leader, Remote Sensing Research Unit (RSRU), CSIR-Meraka Institute for Advanced Information and Communication Technology, CSIR, Pretoria.
• 2005 (Aug.) - 2006 (Aug.): Research Associate, NASA/Goddard Space Flight Center, Hydrospheric and Biospheric Sciences Laboratory and Goddard Earth Sciences Technology Centre, University of Maryland Baltimore County.
• 2002-2005 (Aug.): Research Assistant, Geography Department, UMD. Supervisor: Dr. Stephen D. Prince. The work involved analyzing trends in relationship between net primary productivity (NPP) and climate variables at a global scale.
• 2001-2004: Research assistant, Geography Department, UMD, Supervisor Dr. Ruth DeFries. NASA funded Project entitled, Land Use Change in and Around Protected Areas in LCLUC Sites: Synthesis of Rates and Consequences for Biodiversity. Responsibilities included mapping land cover with MODIS and Landsat satellite data.
• 1997-2001: Researcher, Agricultural Research Council - Institute for Soil, Climate and Water, Remote Sensing and Geo-Informatics Division, South Africa. Promoted to Senior Researcher in 2001. Responsibilities included: project proposal writing, project management, statistical analyses, satellite image processing, field survey planning and implementation, final report writing, producing final remote sensing products and communicating results to funding agencies and data users.
• 1995-1997: MSc student researcher. University of Pretoria, Conservation Planning GIS Laboratory and DeBeers Venetia-Limpopo Nature Reserve. Applied algorithms in GIS to analyze landscape pattern and identify priority conservation areas.
• 1994: Field assistant. U.S. Geological Surveys, Biological Resources Division (formerly National Biological Surveys), Boise Idaho, USA.
• 1994: Field assistant. US Fish and Wildlife Service, Juneau, Alaska.

Grants and Fellowships (selected)

• Principal investigator: CSIR Strategic Research Panel / Thematic Program   project: Time-series Analysis of Hyper-temporal satellite data using High Performance Computing. ZAR 6mil (~US$ 875 000, 2007-2010)
• Co-Investigator: CSIR Strategic Research Panel / Thematic Program project: Integration of lidar and imaging spectroscopy remote sensing for improved characterization of land degradation along a land use gradient and savannah system ecology ZAR 6mil (~US$ 875 000, 2008-2011)
• Principal investigator and project manager of the following grants funded by the National Department of Agriculture (South Africa, 1997 to 2001):
  
  • Developing techniques for Mapping and Monitoring the conservation status of Natural Resources (natural rangeland and soils) of the Mpumalanga Province by means of Remote Sensing and GIS technology.  Funding amount: ZAR 800 000 (~US$133 000)
  • Quantifying the potential impact of Land cover Change by Agriculture and other land uses on Regional Biodiversity.  Funding amount: ZAR 220 000 (~US$36 000)
  • Natural Resource Audit of the Gauteng Province with the aid of Remote Sensing and GIS. Funding amount: ZAR 800 000 (~US$133 000)
  • Monitoring land degradation using AVHRR NDVI, Net Primary Productivity and Rain Use Efficiency.  Funding amount: ZAR 240 000 (~US$40 000)
• NASA Earth System Sciences Fellowship (2002 to 2005) for a project entitled “Modeling and monitoring land degradation in Southern Africa”.  Funding amount (US$ 72 000).

Scholarships and Awards

• NASA Earth System Sciences Fellowship, 2002 to 2005.
• Baker Award for Best Graduate Student in Geography, University of Maryland, 2005.
• Foundation for Research Development (South Africa), Honours (1993) and MSc Scholarships (1995, 1996).
• De Beers Consolidated Mines (South Africa), MSc Scholarship 1995, 1996.
• IBM South Africa scholarships, 1990 to 1993.
• University of Pretoria bursaries 1991-1996.

Refereed Publications

Wessels K.J., Mathieu R., Erasmus B.F.N., Asner G.P., Smit I.P.J., van Aardt J.A.N., Main R., Fisher J., Marais W., Kennedy-Bowdoin T., Knapp D.E., Emerson R., Jacobson J. (2011) Impact of communal land use and conservation on woody vegetation structure in the Lowveld savannas of South Africa. Forest Ecology and Management. 261: 19-29

Wessels K., Steenkamp K., von Maltitz G., Archibald S. (2011) Remotely-sensed vegetation phenology for describing and predicting the biomes of South Africa. Applied Vegetation Science, 14: 49-66.

W. Kleynhans, B.P. Salmon, J.C. Olivier, F. van den Bergh, K.J. Wessels, T.L. Grobler and K. Steenkamp (in press) Land Cover Change Detection Using Autocorrelation Analysis on MODIS Time-Series Data: Detection of new human settlements in the Gauteng province of South Africa. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

Salmon B.P., J.C. Olivier, K.J. Wessels, W. Kleynhans, F. van den Bergh, and K. C. Steenkamp (2011) Unsupervised land cover change detection: Meaningful Sequencial Time Series Analysis. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 4: 327-336

Wessels. K.J. Comments on ‘Proxy global assessment of land degradation’ by Bai et al. (2008) Soil Use and Management, March 2009, 25, 91–92.

Van Den Bergh F., Wessels K.J. et al. (2012) HiTempo: a platform for time-series analysis of remote sensing satellite data in a high performance computing environment. International Journal of Remote Sensing – Time series analysis special issue 33: 4720–4740

Kleynhans, W., J.C. Olivier, K.J. Wessels, F. van den Bergh, B.P. Salmon (in press, on–line) Detecting Land Cover Change Using an Extended Kalman Filter on MODIS NDVI Time-Series Data, IEEE Geoscience And Remote Sensing Letters, VOL. 8, NO. 3, MAY 2011 (IEEE Early access) Doi: 10.1109/LGRS.2010.2089495

Fisher, J.T., E.T.F. Witkowski, B.F.N. Erasmus, J. Van Aardt, G.P. Asner, K. Wessels and R. Mathieu (2012) Human-modified landscapes: patterns of fine-scale woody vegetation structure in communal savanna rangelands. Environmental Conservation 39: 72–82

Kleynhans, W., J.C. Olivier, K.J. Wessels, F. van den Bergh, B.P. Salmon and K. Steenkamp (2010) Improving Land Cover Class Separation using an Extended Kalman Filter on MODIS NDVI Time Series Data. IEEE GeoScience and Remote Sensing Letters. 7(2) 381-385

Wessels, K.J., Prince, S.D., and Reshef, I. (2008) Mapping land degradation by comparison of vegetation production to spatially-derived estimates of potential production. Journal of Arid Environments. 72, 1940-1949.

Wessel K.J., Prince S.D., M. Carroll and J. Malherbe (2007) Relevance of rangeland degradation in semi-arid Northeastern South Africa to the non-equilibrium theory. Ecological Applications. 17, 815-827

Prince S.D., Wessels K.J., Tucker C.J. and Nicholson S.E. (2007) Desertification in the Sahel: a reinterpretation of a reinterpretation. Global Change Biology.13, 1308-1313.

Wessels K.J., Prince S.D., Malherebe J., Small J. and P.E. Frost (2007) Can human-induced land degradation be distinguished from the effects of rainfall variability? A case study in South Africa. Journal of Arid Environments, 68, 271-297.

Wessels K.J., Prince S.D., Zambatis N., MacFadyen S., Frost P.E. and D. VanZyl (2006) Relationship between herbaceous biomass and 1km² Advanced Very High Resolution Radiometer (AVHRR) NDVI in Kruger National Park, South Africa. International Journal of Remote Sensing, 27, 951-973.

Wessels K.J., S.D. Prince, Frost P.E., van Zyl D. (2004) Assessing the effects of human-induced land degradation in the former homelands of northern South Africa with a 1km AVHRR NDVI time-series. Remote Sensing of Environment, 91, 47-67.

Wessels K.J., DeFries, R., Anderson L.O., Hansen A.J., Powell, S.L. and Moran E.F. (2004) Mapping regional land cover with MODIS data for biological conservation: Examples from the Greater Yellowstone Ecosystem, USA and Pará State, Brazil. Remote Sensing of Environment 92, 67-83.

Wessels K.J., Reyers B., Van Jaarsveld A.S. and Rutherford M.C. (2003) Identification of potential conflict areas between land transformation and biodiversity conservation in north-eastern South Africa. Agriculture, Ecosystems and Environment 95, 157-178.

McCarthy J.M., Gumbricht T., McCarthy T., Frost P.E., Wessels K.J. and Seidel F. (2003) Flooding Patterns of the Okavango Wetland in Botswana between 1972 and 2000. Ambio, 32, 453-457.

Gumbricht T., McCarthy T.S., McCarthy J.M., Roy D., Frost P.E., Wessels K.J. (2002) Remote sensing to detect sub-surface peat fires and peat fire scars in the Okavango delta, Botswana. South African Journal of Science 98, 351-358.

Reyers B., Wessels K.J. and van Jaarsveld A.S (2002) An assessment of biodiversity surrogacy options in the Limpopo Province of South Africa. African Zoology 37, 185-195.

Erasmus B.F.N., Van Jaarsveld A.S. Chown S.L.., Kshatriya M. and Wessels K.J. (2002) Vulnerability of South African animal taxa to climate change. Global Change Biology 8, 679-693.

Reyers B., Fairbanks D.H.K., Wessels K.J., and Van Jaarsveld A.S. (2002) A multicriteria approach to reserve selection: Addressing long-term biodiversity maintenance. Biodiversity and Conservation 11, 769-793.

Wessels K.J., Reyers B. and Van Jaarsveld A.S. (2000) Incorporating land cover information into regional biodiversity assessments in South Africa. Animal Conservation 3, 67-79.

Wessels K.J., Freitag S. and Van Jaarsveld A.S. (1999) The use of Land Facets as Biodiversity Surrogates during reserve selection at a Local Scale. Biological Conservation 89, 21-38.

Wessels K.J., Grimbeek J.D., Van Der Linde M.J. and Van Jaarsveld A.S. (1998) An Evaluation of the Gradsect Biological Survey method. Biodiversity and Conservation 7, 1093-1121.

Wessels K.J. and van der Merwe, M. (1997) Facultative spermatozoa storage by female Geoffroy’s horseshoe bat (Rhinolophus clivosus). Canadian Journal of Zoology 75: 2142-2146.
 

Other Publications

Konrad J. Wessels, Karen Steenkamp, Graham Von Maltitz, Sally Archibald (2011) Extracting inter-annual variability in the phenological characteristics of Southern Africa's vegetation using satellite imagery. In Observations on Environmental Change in South Africa. Ed. Larry Zietsman, Sun Press: Stellenbosch. pp 88-91.

Konrad J. Wessels, Patrick C. Dwyer (2011) Impact of ENSO events on the Kruger National Park’s vegetation. In Observations on Environmental Change in South Africa. Ed. Larry Zietsman, Sun Press: Stellenbosch. pp 92-97. 

Konrad J. Wessels (2011) Monitoring land degradation with long-term satellite data. In Observations on Environmental Change in South Africa. Ed. Larry Zietsman, Sun Press: Stellenbosch. pp 105-110.

Jan A.N. van Aardt, Renaud Mathieu, Moses Cho, Konrad J. Wessels, Barend Erasmus, Gregory P. Asner, Izak P.J. Smit, (2011) Assessing degradation across a land-use gradient in the Kruger National Park area using advanced remote sensing modalities. In Observations on Environmental Change in South Africa. Ed. Larry Zietsman, Sun Press: Stellenbosch. pp 98-105.

Wessels, K. and Prince, S. (2007) Monitoring land degradation with long-term satellite data in South Africa. In: The Full Picture. Edited by Group on Earth Observations (GEO) Secretariat. ISBN 978-92-990047-0-8

Contributing author. Dryland Systems. Ch. 22, (2005) In: Ecosystems and Human Well-being: Current State and Trends, edited by the Millennium Ecosystem Assessment, Island Press, Washington DC

Wessels K.J. van Den Berg, H.M. and Pretorius D.J. (2000) Spatial Natural Resource Monitoring in the Mpumalanga Province of South Africa. In: Response to Land Degradation. Eds E.M. Bridges, I.D. Hannam, L.R. Oldeman, F.W.T. Penning de Vries, S.J. Scherr and Samran Sombatpanit, Science Publishers Inc., New Hampshire, USA. ISBN: 1578081521

Newby T.S. and Wessels K.J. (Eds) (1997) Report on the extent of Natural Resource Degradation in South Africa. ARC-ISCW Report: GW/A/97/57, Pretoria.

Wessels K.J. (1999) Quantifying the impact of human activities on biodiversity. In: Framework on Natural Resource Accounting in SA. Department of Environmental Affairs and Tourism report. Pretoria.
 

Oral papers presented (selected)

Remotely sensed phenology for mapping biomes and vegetation functional types. (2009) In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.

The reality of rangeland degradation mapping with remote sensing: the South African experience. K.J. Wessels, D.J. Pretorius, S.D. Prince. 14th Australian Remote Sensing and Photogrammetry Conference. Darwin, Australia. 29 Sept - 3 Oct. 2008

Detection of land cover change using an artificial neural network within a temporal sliding window on modis time series data. IGARSS 2008, Boston. ISBN: 9781424428083

Monitoring desertification’s impact on vegetation production in South Africa using long-term AVHRR and MODIS data: A test of the non-equilibrium rangeland theory. 32nd International Symposium on Remote Sensing of Environment Sustainable Development through Global Earth Observations June 25-29, 2007, San Jose, Costa Rica. ISBN: 978-0-932913-12-8

Monitoring land degradation by assessing primary productivity with satellite data. Seminar NASA GSFC, Greenbelt, USA, 2005.

Taking land cover transformation into account during Biodiversity assessments in South Africa. Society for Conservation Biology annual conference, Missoula, Montanna, USA, 2000.

Spatial Natural Resource Monitoring. 2^nd International Land Degradation Conference, Khon Kaen, Thailand, 1999.

Spatial natural resource monitoring in Mpumalanga. Earth Decision Information Systems Annual conference 1999 CSRI, Pretoria, SA. 1999

Natural Resource Monitoring with Remote Sensing. Decision Support in Agriculture Symposium (ARC-ISCW), Mpekweni Sun, SA, 1998.

Land cover change finally has a say in Regional Biodiversity Assessments. Annual Zoological Society of Southern Africa Symposium. Durban, SA, 1998.
 

Other conference papers (selected, recent)

B. P. Salmon, J. C. Olivier, W. Kleynhans, K. J. Wessels and F. van den Bergh (2010) Automated land cover change detection: The quest for meaningful high temporal time series extraction. IEEE Geoscience and Remote Sensing Symposium 2010 , Hawaii, USA, 25-30 July 2010, p 1968 - 1971

W. Kleynhans, J. C. Olivier, B. P. Salmon, K. J. Wessels and F. van den Bergh,(2010) A spatio-temporal approach to detecting land cover change using an extended Kalman filter on MODIS time series data. IEEE Geoscience and Remote Sensing Symposium 2010, Hawaii, USA, 25-30 July 2010, p1972 - 1975

Salmon, B.P., Olivier, J.C., Kleynhans, W., Wessels, K.J. and van den Bergh, F. (2009) The quest for automated land cover change detection using satellite time series data. In: Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.

Renaud Mathieu, Konrad Wessels, Gregory Asner, David Knapp, Jan van Aardt, Moses Azong Cho, Barend Erasmus, Izak Smit, (2009) Fractional cover and structural variations along a land use degradation gradient in savannas in and around the Kruger National Park, South Africa.

Izak Smit, Gregory Asner, Navashni Govendor, Shaun Levick, Renaud Mathieu, Konrad Wessels, Barend Erasmus, Basjan van Aardt (2009) Fire as browser:using lidar to visualise and quantify woody structure on a long-term fire experiment in an african savanna.  In: Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.

Jiaying Wu, Jan van Aardt Gregory Asner, Renaud Mathieu, Konrad Wessels, Barend Erasmus, Izak Smit, (2009) Connecting the dots between laser waveforms and herbaceous biomass for assessment of land degradation using small-footprint waveform lidar data. In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.  

The Sarvanna Project: SAR Mapping of vegetation structure in the African Savanna. (2009) Christiane Schmullius, Harold Annegarn, Charles Paradzayi, Izak Smit, Wolfgang Lück, Barend Erasmus, Renaud Mathieu, Melanie Vogel, Konrad Wessels. In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.  

Brian Salmon, Jan Olivier, Waldo Kleynhans, Konrad Wessels, Frans Van Den Bergh. (2009) The quest for automated land cover change detection using satellite time series data. In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.  

Waldo Kleynhans, Corne Olivier, Brian Salmon, Konrad Wessels. (2009) Improving NDVI time series class separation using an extended Kalman filter. In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Jul., Cape Town, South Africa.    
 

Conference posters presented (selected)

Wessels K.J., Mathieu R., Asner G.P. , Main R., Smit I.P.J., Erasmus B.F.N., van Aardt J.A.N., Fisher J., Marais W., Kennedy-Bowdoin T., Knapp D.E., Emerson R., Jacobso J. (2010) Impact of land use on tree canopy height distributions determined by Lidar in and around Kruger National Park, South Africa. American Society for Photogrammetry and Remote Sensing (ASPRS) conference, San Diego, April 2010.

Wessels, K. J., A. K. Bachoo, and S. Archibald. (2009). Influence of composite period and date of observation on phenological metrics extracted from MODIS data. in 33rd International Symposium on Remote Sensing of the Environment. ISRSE, Stresa, Italy.

Olivier J.C., Araya, S.T. and Wessels, K.J. (2007) Detection of land cover change using an Artificial Neural Network on a time-series of MODIS satellite data. Pattern Recognition Association of South Africa (PRASA). Pietermaritzburg.

Wessels K.J. and Prince S.D. (2004) Did “Apartheid” cause land degradation in the former homelands of South Africa? - Assessing ecosystem function with 17 years of 1km AVHRR NDVI data. Earth Science Scholars Network Symposium, College Park, Maryland.

Wessels K.J. and Prince S.D. (2004) Assessing the effect of human-induced land degradation on ecosystem function in the former homelands of South Africa. American Geophysical Union meeting, San Francisco.

Reshef I., Prince S.D., and Wessels K.J. (2004) Detection of human induced degradation of dry lands at regional scales. American Geophysical Union meeting, San Francisco.

Wessels K.J., Prince S.D., Small J. (2003) Monitoring Land Degradation in Southern Africa based on Net Primary Productivity. IGARSS Conference, Toulouse, France.

Smith H.J., Wessels K.J. and Twyman L. (2003) Spatial Soil Erosion Modelling for Conservation Planning in the Mpumalanga Province of South Africa. Soil Science Society of South Africa congress, Stellenbosch, awarded “Best Paper/Poster on New, Implementable Technology”

Wessels K.J., Prince S.D. and Reshef I. (2001) Detection and Mapping of Desertification. American Geophysical Union meeting, San Francisco.

Wessels K.J., Van den Berg H.M. and Van der Merwe A. (2000) Spatial natural resource monitoring in Mpumalanga province of South Africa. 28^th International Symposium on Remote Sensing of the Environment. Cape Town.

Van der Merwe A., Wessels K.J., van den Berg H.M. and Fortescue A. (2000) A benchmark approach to map rangeland condition from Landsat TM imagery in the Mpumalanga province of South Africa. 28^th International Symposium on Remote Sensing of the Environment. Cape Town.

Van den Berg H.M., van der Merwe A. and Wessels K.J. (2000) Soil and vegetation mapping using point data and multi-surface modeling. Accuracy 2000 Symposium, Amsterdam.

Frost P.E. and Wessels K.J. (2000) Identification and evaluation of potentially degraded areas in Mpumalanga using NOAA NDVI and rainfall data. Grassland Society of SA congress, Zimbabwe.

Hoare D. and Wessels K.J. (2000) Diversity and Conservation of Highveld grasslands. South African Association of Botanists Symposium, Cape Town.

Reyers B., Wessels K.J., and van Jaarsveld A.S. (1999) Rangeland transformation in northern South Africa: prospects for biodiversity conservation. International Rangeland Conference, Townsville, Australia.

Van den Berg H.M., Westfall B. and Wessels K.J. (1999) Identification and mapping of plant functional types using remote sensing and GIS modeling. International Rangeland Conference, Townsville, Australia.

Wessels K.J. and Frost P.E. (1999) NOAA NDVI dataset for long-term ecological research. Long term ecological research workshop. Skukuza, South Africa.
 

Referee for Journals

• Remote Sensing of Environment
• International Journal of Remote Sensing
• Journal of Geophysical Research
• Regional Environmental Change
• Photogrammetric Engineering & Remote Sensing
• Applied Vegetation Science
• Global Change Biology 

Co-Supervision

• Philemon Tsela. MSc Department of Geography, Geo-Informatics and Meteorology, University of Pretoria. (2011).
• Jolene Fisher. MSc Three-dimensional woody vegetation structure across land-use types and intensities in a semi-arid savanna. MSc School of Animal, Plant and Environmental Sciences, WITS (MSc thesis upgraded to PhD).
• Brian Salmon. PhD TBD Dept. Electrical, Electronic and Computer Engineering, University of Pretoria (PhD thesis submitted - graduating 2011).
• Waldo Kleynhans. PhD Detecting Land-cover change using MODIS time-series data. Dept. Electrical, Electronic and Computer Engineering, University of Pretoria (graduated 2011).
• Patrick Dwyer. MSc Spatial Estimation of Herbaceous Biomass Using Remote Sensing in Southern African Savannas. Animal, Plant and Environmental Sciences, WITS (graduated 2011).
• Lee-Ann Sinden. PhD Impacts of climate and climate change on vegetation in the Lowveld. School of Animal, Plant and Environmental Sciences, WITS (MSc thesis upgraded to PhD).
• Kerry Cause. PhD Using Random Matrix Theory to determine the intrinsic dimension of a hyperspectral image. Department of Computational and Applied Mathematics, WITS. (Submitting Nov 2011).
• Philip Frost. MSc Development of fire flashover prediction model for electricity transmission lines. Department of Geography, University of Johannesburg (graduated 2011)

External examiner

Dept Environmental and Geographical Science, University of Cape Town.
 

Other Courses attended

• Investment in Excellence - The Pacific Institute, CSIR, 2009.
• ERDAS-Imagine, image processing software, GIMS, Nov. 1998.
• ArcView Spatial Analyst, GIMS, Nov. 1998.
• Project management course, CSIR, Pretoria, 2000.
• Creative Research and Development Management course, Inside Lane, Oct. 1997.
• Marketing course, Inside Lane, Aug. 1997.

Technical proficiency

• ERDAS Imagine, image processing
• ENVI image processing
• ArcView GIS
• PCI EASI scripting, image processing
• UNIX and shell scriptingS-PLUS statistical software

References

S.D. Prince. Department of Geography, University of Maryland, 2181 LeFrak Hall, College Park, MD 20742, USA, sprince@geog.umd.edu, tel: 301-405 4062,     fax: 301-314 9299

J. Townshend. Chair of Geography Department, University of Maryland, 2181 LeFrak Hall, College Park, MD 20742, USA, jtownshe@geog.umd.edu tel: 301 405 4567