Patch–Terrain Coupling and Resistance-Based Connectivity Adjustment for Assessing Contiguous Cropland Consolidation Potential in Hilly Terraced Regions: A Case Study of Huangzhong District, China

Abstract

Cropland fragmentation remains a major constraint on agricultural mechanization, land consolidation, and cropland protection in hilly and mountainous regions. In terraced landscapes, cropland patches that appear close in planar space may nevertheless be difficult to connect because of steep slopes, terrain relief, gullies, and river networks. Conventional assessments based mainly on two-dimensional adjacency or patch size may therefore overestimate the relative suitability of cropland for spatially coordinated consolidation when terrain- and hydrology-related resistance is ignored. In this study, contiguous cropland consolidation potential is defined as a regional screening-level measure of the relative suitability of existing cropland patches for spatially coordinated consolidation, rather than as a comprehensive assessment of project-level land consolidation feasibility. Taking Huangzhong District, Xining City, China, as a case study, we developed a regional screening framework integrating cropland patch spatial characteristics, terrain–hydrological suitability, and resistance-based connectivity adjustment. Cropland evaluation units, defined as vector cropland patches, were independently derived from the 2025 Esri Sentinel-2 10 m Land Use/Land Cover Time Series product, while single-date Sentinel-2 imagery was used only for auxiliary visualization and cartographic presentation. The analysis followed a three-stage logic. First, cropland spatial characteristics and terrain–hydrological suitability were integrated using AHP–entropy weighting to estimate the initial regional consolidation suitability of each cropland unit. Second, relatively favorable cropland patches were identified as core sources, and minimum cumulative resistance analysis was used to quantify the resistance-based connection of each unit to the core-source network. Finally, the initial suitability was adjusted using the resulting resistance-based connectivity proxy to derive the final contiguous cropland consolidation potential index. The final assessment revealed clear spatial differentiation among the 1507 cropland evaluation units. Although the three potential classes contained similar numbers of patches, the high-potential class accounted for 88.285% of the total cropland area, indicating a strongly uneven area distribution among potential classes. High-potential areas were concentrated mainly in the north-central and south-central farming zones, where terrain conditions were relatively favorable and cumulative resistance was lower, whereas lower-potential units occurred more frequently in southern and marginal areas characterized by stronger terrain dissection and higher resistance. After resistance-based connectivity adjustment, 88.334% of the cropland area retained its original potential grade, while 10.733% was downgraded. This pattern indicates that the adjustment did not broadly overturn the initial assessment but mainly affected cropland units whose favorable patch–terrain conditions were offset by less favorable modeled connection to the core-source network. These findings demonstrate the value of distinguishing intrinsic patch–terrain suitability from resistance-based connection when screening contiguous cropland consolidation potential in hilly terraced regions.