Potgieter, Andries B. and Apan, Armando and Hammer, Graeme L. and Dunn, Peter K. (2005) Spying on the winter wheat crop - generating objective planted area and crop production estimates using MODIS imagery. In: SSC 2005 Spatial Sciences Institute Biennial Conference, 12-16 Sep 2005, Melbourne, Australia.
With world commodity markets becoming more competitive and the deregulation of the wheat industry in Australia during the nineties, advanced knowledge of likely production and its geographical distribution has become highly sought-after information. During the past 5 years, the Queensland Department of Primary Industries & Fisheries (DPI&F) has generated shire/state and national yield (t/ha) forecasts for wheat and sorghum crops on a monthly basis throughout the crop-growing season with appreciable success. However, to achieve an accurate near real-time production forecast, a real-time estimate of the crop area planted is required. Generating objective estimates of planted area will allow near real-time crop production estimates, which can then be used in updating supply chain information at the regional, state and national levels. While there are alternative methods (e.g. subjective opinions, surveys, censuses, etc.) to derive the required information, the use of remote sensing (RS) offers more objectivity, timeliness, repeatability and accuracy. Furthermore, the use of multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) imagery (spanning an entire cropping season) is novel, and has been rarely used in determining crop area planted in targeted agricultural systems. In this paper, we provided a brief background of regional commodity forecasting in Queensland, and have reported some preliminary results on the use of digital image processing techniques to determine crop area planted. More specifically, different multivariate approaches to analysing remote sensing data [i.e. Harmonic Analysis of Time Series (HANTS) and Principal Component Analysis (PCA)] were compared in determining winter crop area planted from MODIS imagery for a specific case study in the Darling Downs region, Queensland. The methodology was validated for the 2003 and 2004 seasons at a shire level by contrasting aggregated shire total area planted with surveyed ABARE estimates. Finally, the ability of these methods to discriminate area planted for wheat, barley and chickpea at the shire level was determined. Preliminary results showed a significant potential to capture total crop area planted at a regional level and a good overall capability (>95% correct classification) in discriminating between these winter crops.
|Item Type:||Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)|
|Uncontrolled Keywords:||multi-temporal, harmonic analysis, principal component analysis, national grain yields, MODIS imagery, commodity forecasting|
|Subjects:||290000 Engineering and Technology > 291000 Geomatic Engineering > 291003 Photogrammetry and Remote Sensing
340000 Economics > 340400 Econometrics > 340401 Economic Models and Forecasting
|Depositing User:||epEditor USQ|
|Date Deposited:||11 Oct 2007 00:24|
|Last Modified:||02 Jul 2013 22:32|
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