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-based product was greater than the accuracy of either the harmonic decomposition or MOD12Q1 products for the years 2001, 2003 and 2008. However, the accuracy of the PCA product was only slightly better than the MOD12Q1 for 2001 and 2003. Overall, the results suggest that our PCA-based approach produces a high level of user and producer accuracies, although the MOD12Q1 product also showed consistently high accuracy. Overlay of 2001–2008 PCA-based maps showed a net increase of 12,129 ha of irrigated vegetation, with the largest increase found from 2006 to 2008 around the districts of Edfu and Kom Ombo. This result was unexpected in light of ambitious government plans to develop 336,000 ha of irrigated agriculture around the Toshka Lakes.

尼罗河沿岸的灌溉使上埃及的生物物理环境发生了巨大变化。在这项研究中，我们结合使用中分辨率成像光谱仪 (MODIS) 250 m 归一化差异植被指数数据和 Landsat 图像来识别从 2001 年到 2008 年因尼罗河及附近灌溉和水位波动而发生变化的区域水体。我们使用了两种不同的时间序列分析方法——主成分分析 (PCA) 和谐波分解——应用于 MODIS 250 m 归一化差异植被指数图像，以获得简单的三级土地覆盖图，然后使用一组来自 30 m Landsat 5 和 7 影像的参考多边形。我们针对新的 MODIS 全球土地覆盖产品（MOD12Q1 系列 5）分析了我们的 MODIS 250 m 地图，以评估区域特定的制图方法是否优于标准的全球产品。结果表明，2001年、2003年和2008年基于PCA的产品精度高于谐波分解或MOD12Q1产品的精度。然而，PCA产品的精度仅略好于2001年的MOD12Q1和 2003 年。总的来说，结果表明我们基于 PCA 的方法产生了高水平的用户和生产者准确度，尽管 MOD12Q1 产品也显示出一贯的高准确度。2001-2008 年基于 PCA 的地图的叠加显示，灌溉植被净增加了 12,129 公顷，其中在 2006 年至 2008 年期间发现的增幅最大的是埃德富和康翁波地区。