Land use and land cover changes such as agricultural land abandonment along with soil erosion are perceived to be important factors that add to land degradation worldwide. In this study, we used aerial imagery, archival-Structure from Motion (SfM) reconstruction and airborne-LiDAR surveys to reconstruct land abandonment along with pipe collapse and gully development in a semi-arid Mediterranean catchment area of the Ebro Valley (Spain) during 1957–2021. Agricultural land dynamics were analysed from the study of planform changes to field crops. Land degradation associated to pipe collapse and gully development was inferred from the geomorphic change detection deduced from the comparison of topographic models obtained from archival-SfM and LiDAR datasets. Through spatial correlation analysis, we identified that higher, steeper, and more hydrologically connected field crop areas were the first to be abandoned. Additionally, the extent of pipe collapses and gullying processes was significantly correlated with the degree of land abandonment over the duration of the study period. Our findings reveal that approximately 20 % of agricultural lands within the study area were abandoned during said study period, with up to 15 % of the abandoned area directly impacted by pipe collapse and gullying processes. Erosion rates associated with these processes within the catchment, implied erosion areas of 3.9 ha and 1.5 ha for the period 1977–2009 and 2009–2021, ranging between 120 Mg/ha yr−1 and 203.2 Mg/ha yr−1, respectively. Our study highlights that abandonment in said area is predominantly conditioned by land degradation resulting from pipe collapses and gully development. The recognition and protection of piping and gully affected areas as geodiversity sites is presented as an alternative at a local level to mitigate the economic impacts of soil degradation. Understanding the effects that pipe collapse and gully development have on arable lands over long-term study periods (i.e., >50 years) is essential in order to shed light on the interconnected factors influencing land productivity and agricultural sustainability. This ultimately guides us to make informed policy decisions that mitigate these detrimental effects.

中文翻译：

---

与管道坍塌和沟壑开发相关的农业用地撂荒：从档案 SfM 和 LiDAR 数据集重建


土地利用和土地覆盖变化（例如农业用地撂荒和水土流失）被认为是导致全球土地退化的重要因素。在这项研究中，我们使用航空图像、运动档案结构 （SfM） 重建和机载 LiDAR 调查来重建 1957 年至 2021 年间埃布罗河谷（西班牙）半干旱地中海集水区的土地撂荒以及管道坍塌和沟壑开发。通过对大田作物的平面形态变化的研究，分析了农业用地动态。与管道坍塌和沟壑开发相关的土地退化是从从档案 SfM 和 LiDAR 数据集获得的地形模型的比较中推断出的地貌变化检测。通过空间相关性分析，我们确定更高、更陡峭、水文联系更紧密的田间作物区最先被放弃。此外，管道坍塌和沟渠过程的程度与研究期间土地撂废程度显著相关。我们的研究结果表明，在上述研究期间，研究区域内大约 20% 的农业用地被废弃，高达 15% 的废弃区域直接受到管道坍塌和沟壑过程的影响。与集水区内这些过程相关的侵蚀率，1977-2009 年和 2009-2021 年期间的隐含侵蚀面积为 3.9 公顷和 1.5 公顷，分别在 120 毫克/公顷 yr-1 和 203.2 毫克/公顷 yr-1 之间。我们的研究强调，上述地区的废弃主要受到管道坍塌和沟壑开发导致的土地退化的影响。 在地方层面，将管道和沟壑影响区域作为地质多样性地点进行承认和保护，作为减轻土壤退化经济影响的替代方案。了解管道坍塌和沟壑开发在长期研究期间（即 >50 年）对耕地的影响对于阐明影响土地生产力和农业可持续性的相互关联的因素至关重要。这最终会指导我们做出明智的政策决策，以减轻这些不利影响。