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An Image C lassification of Khartoum, Sudan

This project aims to delineate Khartoum's urban extent by classifying a Landsat ETM+ 2006 image into urban, desert, fallow, agriculture, and water classes. The classification process in ENVI involves composite bands and unsupervised/supervised techniques.

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An Image C lassification of Khartoum, Sudan

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  1. by Lia Sullivan An Image Classification ofKhartoum, Sudan

  2. Landsat ETM+ 2006 Image of Khartoum Global Land Cover Facility www.landcover.org

  3. Delineate the urban extent of Khartoum. • Create 5 output classes in the process: • urban • desert • fallow • agriculture • water • Become acquainted with the classification process in ENVI. Project Goals

  4. Composite Bands Used - Bands 7,4,2 Bands 4,3,2 Equalization Stretch Linear 5% Stretch

  5. Processes Used Bands 1,2,3,4,5,7 were combined using layer stacking tool. UnsupervisedClassificationof 30 classes.

  6. 33 training samples drawn using false color images and unsupervised classification to identify class types. Supervised Classification Regions of Interest: ROI’s Using Roi’s ran a Maximum Likelihood Classsification and a Mahalanobis Classification

  7. Output Comparison of Urban Classes Maximum Likelihood Mahalanobis Urban/Fallow/Ag confusion Urban/Desert confusion

  8. Used thresholding Troubleshooting Set Maximum Likelihood parameter to a probability of.9 or 90%

  9. Output Comparison Of UrBan Classes Thresholding No Thresholding Unclassified

  10. Exported the “problem” class to a vector file. Drew 15 more training samples within its boundary paying close attention to the spectral profile of my samples. Troubleshooting Cont.

  11. Performed a supervised classification, using the mask option along with thresholding so that only areas within the confused class were reclassified. The goal being to test the efficacy of these training samples on the problem area alone. Fallow Classes On Improved Results

  12. Combined new training samples with first set. • Ran another maximum likelihood classification with thresholding • Used the Rule Classifier Tool to combine class Final Output

  13. Final Output: Problem Areas

  14. Unclassified area: More training samples taken within the unclassified area. Problematic spectral profile: More than one class shared the same spectral profile. Develop an effective decision tree to try to resolve confusion. Challenges Encountered Potential Solutions

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