Dr. Izaya Numata is an Assistant Research Professor at the Geospatial Sciences Center of Excellence, SDSU. His research interests are in monitoring, characterizing and evaluating land-use and land-cover (LULC) dynamics and human-environmental interactions that cause LULC change. His primary concern is to understand interchangeable relationships between human activity and the environment that drive LULC change. His research approach includes intensive use of remote sensing for biophysical and chemical characterization of land surfaces (land covers and land uses), monitoring its change, and the integration of different sources of data through GIS for the analysis of processes and consequences of LULC change at different spatial and temporal scales.
He has investigated Amazonian pasture dynamics under the combined influences of environmental (soil and climate) and human-factors (grazing intensity and pasture types) across different spatial scales in order to determine the requirements for establishing pasture sustainability in the Amazon. He also uses a variety of remote sensing data and techniques to study forest disturbances which include forest fragmentation and forest fire in the Amazon Basin. Additionally, he has been working on land- cover mapping and change detection in the Amazon using remote sensing.
Souza Jr, C.M., Siqueira, J.V., Sales, M.H., Fonseca, A.V., Ribeiro, J.G., Numata, I., Cochrane, M.A., Barber, C.P., Roberts, D.A., Barlow, J. 2013. “10-year Landsat classification of deforestation and forest degradation in the Brazilian Amazon”. Remote Sensing, Vol 5, 11. Pages:5493-5513.
Toomey, M., Roberts, D.A., Caviglia-Harris, J., Cochrane, M.A., Dewes, C., Harris, D., Numata, I., Sales, M.H., Sills, E., Souza, C. 2013. “Long term carbon balance of the Amazonian frontier: the importance of high spatial and temporal resolution land cover monitoring”. JGR Biogeosciences, Vol 118, 2. Pages 400-411.
Silveira, J.M., Barlow, J., Andrade, R.B., Louzada, J., Mestre, L.A., Lacau, S., Zanetti, R., Numata, I., Cochrane, M.A. 2012 "The responses of leaf litter ant communities to wildfires in the Brazilian Amazon: a multi-region assessment". Biodiversity and Conservation. doi:10.1007/s10531-012-0426-8.
Numata, I., Cochrane, M.A. 2012. "Forest fragmentation and its potential implications in the Brazilian Amazon between 2001 and 2010". Open Journal of Forestry. Vol 2, 265-271. doi:10.4236/ojf.2012.24033.
Barlow, J., Silveira, J.M., Mestre, L.A.M., Andrade, R.B., D'Andrea, G.C., Louzada, J., Vaz-de-Mello, F.Z., Numata, I., Laceu, S., Cochrane, M.A. 2012. "Wildfires in Bamboo-dominated Amazonian Forest: Impacts on above-ground biomass and biodiversity". PLoS One. 7(3): e33373. doi:10.1371/journal.pone.0033373.
Numata, I., Cochrane, M.A., Souza, C.M., Sales, M.H. 2011. “Carbon emissions from deforestation and forest fragmentation in the Brazilian Amazon”. Environmental Research Letters. 6, 044003. doi:10.1088/1748-9326/6/044003.
Numata, I. 2011. "Characterization on pastures using field and imaging spectrometers". Chapter 9. Thenkabail, P., Lyon, J.G., Huete, A. (Eds), "Hyperspectral Remote Sensing of Vegetation", Talyor and Francis. 207-225
Numata, I., Cochrane, M.A., Galvao, L.S. 2011. "Analyzing the impacts of frequency and severity of forest fire on the recovery of disturbed forest using Landsat time series and EO-1 Hyperion in the Southern Brazilian Amazon". Earth Interactions, 15. 14. 1-17, doi:10.1175/2010EI372.1
Numata, I., Cochrane, M.A., Roberts, D.A., Soares, J.V., Souza Jr., C.M., Sales, M.H. 2010. "Biomass collapse and carbon emissions from forest fragmentation in the Brazilian Amazon". Journal of Geophysical Research-Biogeosciences 115. G03027, doi:101029/2009JG001198.
Numata, I., Cochrane, M.A., Roberts, D.A., Soares, J.V. 2009 "Determining dynamics of spatial and temporal structures of forest edges in South Western Amazonia". Forest Ecology and Management 258. 2547-2555
Galvao, L.S., Roberts, D.A., Formaggio, A,R., Numata, I., Breunig, F.M. 2009 "View angle effects on the discrimination of soybean variaties and on the relationships between vegetation indices and yield using off-nadir Hyperion and MODIS data". Remote Sensing of Environment 113. 846-856
Numata, I., Roberts, D.A., Chadwick, O.A., Schimel, J.P., Galvão, L.S., Soares, J.V. 2008. “Evaluation of hyperspectral data for pasture characterization in the Brazilian Amazon using field and imaging spectrometers”. Remote Sensing of Environment. 112. 156901583
Numata, I., Roberts, D.A., Sawada, Y., Chadwick, O.A., Schimel, J.P., Soares, J.V. 2007. “Regional characterization of pasture changes through time and space in Rondônia using remote sensing.” Earth Interactions. 11. 14. 1-25. doi: 10.1175/EI232.1
Numata, I., Roberts, D.A., Chadwick, O.A., Schimel, J.P., Sampaio, F.F., Leonidas, F.C., Soares, J.V. 2007. “Characterization of pasture biophysical properties and the impact of grazing intensity using remotely sensed data”. Remote Sensing of Environment. 108. 314-327.
Numata, I., Chadwick, O.A., Roberts, D.A., Schimel, J.P., Sampaio, F.F., Leonidas., F.C., Soares., J.V. 2007. “Temporal and spatial nutrient variation in post-forest pastures, Rondônia, Brazil”. Agriculture, Ecosystems & Environment. 118. 159-172.
Powell, R.L., Matzke, N., de Souza, C., Clark, M., Numata, I., Hess, L.L., Roberts., D.A. 2004. “Sources of error in accuracy assessment of thematic land-cover maps in the Brazilian Amazon”, Remote Sensing of Environment, 90. 2. 221-234
Holmes, K.W., Roberts, D.A., Sweeney. S., Numata, I., Matricardi, E., Biggs, T., Batista, G., Chadwick, O.A. 2004. “Soil databases and the problem of establishing regional biogeochemical trends”. Global Change Biology, 10. 5. 796-814
Numata, I., Soares, J.V., Roberts, D.A., Leônidas, F.C., Chadwick, O.A., Batista, G.T. 2003. “Relationships among soil fertility dynamics and remotely sensed measures across pasture chronosequences in Rondônia, Brazil”. Remote Sensing of Environment, 87. 4. 446-455
Roberts, D.A., Numata, I., Holmes, K., Batista, G.T., Krug, T., Monteiro, A., Powell., B., Chadwick, O.A. 2002. “Large area mapping of land-cover change in Rondônia using multitemporal spectral mixture analysis and decision tree classfiers”. J. Geophys. Res. Atm., D10.
Ponzoni, F.J., Gomes, A.R., Maldonado, F.D., Sassagawa, H.Y., Numata, I., Araújo, L.S. 2002. “Comparação entre o fator de reflectância bidirecional de um dossel de mudas de Eucaliptus grandis e o fator de reflectância direcional hemisférico de suas folhas isoladas”. CERNE, v.8, n.1, 59-68. (in Portuguese)
Numata, I., Soares, J.V., Leônidas, F.C. 2002. “Dinâmica da fertilidade de solo da Amazônica sob efeito da conversão de floresta por pastagem”. Revista de Sociedade Brasileira de Ciência de Solos. 26: 949-955 (in Portuguese)