Spatio-temporal diagnosis of land fragmentation in the Yellow River Basin: providing a basis for comprehensive land improvement

CONTEXT Land fragmentation (LF) poses a major challenge to sustainable land management, land consolidation, and agricultural productivity, especially in ecologically sensitive and strategically important regions such as the Yellow River Basin (YRB) in China. This area faces prominent issues such as LF and land degradation during land-resource utilization, underscoring the need for spatially adaptive governance and targeted land consolidation strategies. OBJECTIVE This study aims to systematically examine the spatiotemporal evolution of LF in the YRB from 2000 to 2022, with the goal of identifying regional differentiation patterns and influencing factors. It further seeks to propose tailored land consolidation strategies based on fine-grained spatial assessment and functional zoning, in order to support sustainable land use and national food security. METHODS Landscape pattern indices and profile line analysis were used across five time periods to capture LF dynamics. A composite land fragmentation index (LFI) is developed from six landscape metrics, weighted by the entropy method, enabling high-resolution spatial evaluation at the grid scale. Additionally, a Four-Quadrant Model was applied to classify functional zones for land consolidation, incorporating factors such as elevation, temperature, and GDP. RESULTS AND CONCLUSIONS LF in the YRB exhibits significant regional variation, with lower fragmentation in the upper reaches and higher fragmentation in eastern regions—especially in Shanxi and Shandong provinces. Over 60% of the basin remained stable, and LF was strongly associated with elevation, temperature, and economic activity. Based on these patterns, four functional zones were delineated: dynamic reconstruction, optimization and enhancement, steady-state restoration, and collaborative demonstration areas. Comprehensive policy suggestions are provided for integrated land consolidation aligned with LF characteristics and zonal planning. SIGNIFICANCE This study innovatively developed a scientific and systematic LF evaluation framework from a raster-based perspective. Using this framework, we conducted a precise quantitative analysis of the dynamic LF process and explored the mechanisms and impacts of various factors such as policy direction, natural environmental conditions, and socioeconomic factors on LF. Based on the LF findings, this study proposes a comprehensive and feasible land consolidation plan, providing solid, reliable data support for the plan's rationale and scientific foundation. The results are of significant theoretical and practical value for optimizing land resource allocation, enhancing land use efficiency, and promoting regional sustainable development.