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基于历史复耕行为的四川省撂荒耕地复耕潜力及分区

Recultivation potential and zoning of abandoned cropland based on historical abandonment–recultivation events in Sichuan Province

  • 摘要: 撂荒耕地治理不仅需要掌握其规模与空间分布,还需要识别不同撂荒耕地的实际复耕可能性。现有复耕潜力评价多侧重地形、土壤和区位等条件,对历史复耕行为反映的实际利用差异关注不足。本文基于Landsat系列遥感影像构建1997—2025年四川省30 m分辨率逐年土地覆盖数据集,逐年识别耕地撂荒与复耕过程并分析其时空变化,再以历史“撂荒—复耕”事件为样本,构建Stacking复耕概率预测模型,并结合SHAP方法解释影响因素的作用关系,进而评价2025年现存撂荒耕地的复耕潜力。结果表明:(1)2000—2025年四川省年度现存撂荒耕地面积持续增加,由1 897.48km2增至35 034.2km2;年度复耕面积则呈波动状态,二者变化并不同步。(2)连续撂荒年数是复耕概率预测中重要性最高的因素,地均农业产值、机械化强度、耕地连通性、高程和坡度的重要性次之。连续撂荒约7年后对复耕概率的贡献由正转负,坡度约20°以上总体表现为负向贡献。(3)2025年低、中、高复耕潜力区分别占当年撂荒耕地面积的98.23%、1.19%和0.58%。县域尺度上,撂荒规模与复耕潜力的空间分布并不完全一致。本研究从历史复耕行为角度补充了基于理论视角的复耕潜力评价,为撂荒耕地优先核查、潜力分级和分类治理提供了参考。

     

    Abstract: Managing abandoned cropland requires knowledge of its extent and spatial distribution, as well as an assessment of the likelihood that individual abandoned parcels will return to cultivation. Existing studies of recultivation potential mainly consider terrain, soil, location and related conditions. They give less attention to differences in actual land use outcomes reflected in historical recultivation behavior. This study therefore assessed the recultivation potential of existing abandoned cropland in Sichuan Province, China, using evidence from historical recultivation behavior. This study first constructed an annual land cover dataset for Sichuan Province at a spatial resolution of 30 m for 1997–2025 using Landsat imagery. This dataset provided the basis for identifying cropland abandonment and recultivation each year and analyzing their spatial and temporal changes. Historical abandonment–recultivation events were then used as samples to develop a Stacking model for predicting the probability of recultivation of abandoned cropland. Shapley additive explanations (SHAP) analysis quantified the contributions of individual factors to model predictions and identified the importance and direction of the contributions of the main factors. Finally, the model was applied to cropland that remained abandoned in Sichuan Province in 2025 to assess its recultivation potential. The spatial distributions of abandonment extent and recultivation potential were also compared at the county level. The results showed that: (1) From 2000 to 2025, the area of remaining abandoned cropland in Sichuan Province increased continuously from 1,897.48 km2 to 35,034.20 km2. Annual recultivated area fluctuated during the same period. Changes in the area remaining abandoned and in annual recultivated area were not synchronized. (2) The number of consecutive years of abandonment was the most important predictor of recultivation probability, followed by agricultural output per unit area, mechanization, cropland connectivity, elevation, and slope. SHAP analysis showed that the contribution of consecutive years of abandonment to model predictions shifted from positive to negative after approximately seven years. Slope generally made a negative contribution to model predictions when it exceeded approximately 20°. (3) In 2025, low, moderate, and high recultivation potential zones accounted for 98.23%, 1.19%, and 0.58% of the abandoned cropland area, respectively. Low recultivation potential characterized the vast majority of the area assessed. The county-level comparison showed that the spatial distribution of abandonment extent did not fully correspond to that of recultivation potential. This study incorporated differences in actual land use outcomes reflected in historical recultivation behavior to complement theoretically based assessments of recultivation potential. The results provided a reference for identifying abandoned cropland for priority verification, classifying recultivation potential, and developing differentiated management strategies.

     

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