Increasing population and the consequent rise in the demand for food and water resources pose significant challenges for the future of agriculture in Egypt. Rapid large-scale agricultural expansion has occurred in the country to meet the growing demand, but agricultural loss from urban infringement and field abandonment remains prevalent. Documenting the full spectrum of changes within Egypt’s agricultural systems is crucial for developing effective land-use policies that improve food security. Here we map and estimate the areal extent of multiple types of agricultural change in Egypt (i.e., agricultural gain, agricultural abandonment, and agricultural loss from urban growth) by applying the Landsat-based detection of trends in disturbance and recovery (LandTrendr) algorithm, a widely used time series temporal segmentation algorithm. First, we used LandTrendr to identify areas of agricultural gain and loss throughout Egypt from 1987 to 2019. Second, we combined land-cover maps and the LandTrendr results to create a comprehensive land-cover change map. Lastly, we evaluated the accuracy of our findings and estimated per-class areas with quantified uncertainty using high-quality reference data. Our results reveal a notable expansion in Egypt’s agricultural land area. However, this growth is accompanied by the widespread loss of prime agricultural land, a consequence of urban development and agricultural abandonment. This study emphasizes the pressing need for the implementation of sustainable land-use policies in Egypt, particularly as climate change will exacerbate pressures on the agricultural sector in the future.

中文翻译：

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使用 Landsat 时间序列估计埃及农业范围的扩大和减少


人口的增加以及随之而来的对粮食和水资源的需求的增加对埃及农业的未来构成了重大挑战。为了满足不断增长的需求，该国的农业迅速大规模扩张，但因城市侵占和田地废弃而造成的农业损失仍然普遍存在。记录埃及农业系统内的全方位变化对于制定有效的土地利用政策以改善粮食安全至关重要。在这里，我们通过应用基于陆地卫星的干扰和恢复趋势检测 (LandTrendr) 算法，绘制并估计了埃及多种类型农业变化的面积范围（即农业收益、农业废弃和城市增长造成的农业损失），一种广泛使用的时间序列时间分割算法。首先，我们使用 LandTrendr 确定了 1987 年至 2019 年埃及各地农业增减的区域。其次，我们将土地覆盖图和 LandTrendr 结果结合起来，创建了全面的土地覆盖变化图。最后，我们评估了我们的研究结果的准确性，并使用高质量的参考数据估计了具有量化不确定性的每类区域。我们的结果显示埃及农业用地面积显着扩大。然而，这种增长伴随着主要农业用地的广泛丧失，这是城市发展和农业废弃的结果。这项研究强调埃及迫切需要实施可持续土地利用政策，特别是因为气候变化将加剧未来农业部门的压力。