Land cover in Upper Egypt assessed using regional and global land cover products derived from MODIS imagery

Irrigation along the Nile River has resulted in dramatic changes in the biophysical environment of Upper Egypt. In this study we used a combination of Moderate Resolution Imaging Spectroradiometer (MODIS) 250 m Normalized Difference Vegetation Index data and Landsat imagery to identify areas that changed from 2001 to 2008 as a result of irrigation and water-level fluctuations in the Nile River and nearby waterbodies. We used two different methods of time series analysis – principal components analysis (PCA) and harmonic decomposition – applied to the MODIS 250 m Normalized Difference Vegetation Index images to derive simple three-class land-cover maps and then assessed their accuracy using a set of reference polygons derived from 30 m Landsat 5 and 7 imagery. We analysed our MODIS 250 m maps against a new MODIS global land-cover product (MOD12Q1 collection 5) to assess whether regionally specific mapping approaches are superior to a standard global product. Results showed that the accuracy of the PCA-base...