An enhanced methodological framework for objective assessment of regional land subsidence risks: a case study in Cangzhou city, China

Abstract

Regional land subsidence risk assessment is often constrained by low-resolution contour-based continuous data and subjective empirical grading, which may weaken the objectivity and spatial detail of evaluation results. To address this limitation, this study establishes an enhanced methodological framework for objective regional land subsidence risk assessment by integrating high-resolution remote-sensing raster data, an enhanced raster information quantity method, AHP-EWM combined weighting, natural-break risk zoning, and sensitivity analysis. The framework organizes 11 indicators into hazard, vulnerability, and exposure components. The raster information quantity method assigns objective class-level risk scores based on observed raster deformation intensity, whereas AHP-EWM weighting combines literature-based process understanding with data-driven variability. This enhanced methodological framework supports a complete evaluation process, from index construction and class-level scoring to integrated weighting, risk zoning, and stability verification. The results indicate that deep groundwater exploitation and land subsidence rate are the dominant hazard-related factors, whereas road proximity, population density, gross domestic product, and land use strongly influence exposure-related risk. The comprehensive risk pattern shows clear spatial heterogeneity, with higher-risk zones mainly concentrated where strong subsidence hazards, high vulnerability, and dense socioeconomic exposure overlap. Sensitivity analysis indicates that most areas remain unchanged or change by only one risk class under alternative classification schemes, demonstrating good stability and robustness. This study provides a reproducible methodological reference for high-resolution and objective assessment of regional land subsidence risk. Proposes a robust index system for regional land subsidence risk assessment. Formulates an enhanced raster information quantity method in individual index scoring of land subsidence risk assessment. Assesses zoning stability through sensitivity analysis and relates higher-risk zones to infrastructure exposure. Provides transferable methodology for global geohazard-prone regions