Developing a Composite Risk Index for Secondary Soil Salinization Based on the PSR Sustainability Framework

Risk assessment of secondary soil salinization, which is caused in part by the way of people manage the land, is a challenge to agricultural sustainability. The objective of our study was to develop a soil salinity risk assessment model by selecting a consistent set of risk factors based on the conceptual Pressure-State-Response sustainability framework, incorporating the grey relational analysis and the Analytic Hierarchy Process methods. The development of the composite risk index for secondary soil salinization was presented through a case study in the Yinchuan Plain of China. Fourteen risk factors were selected in terms of three PSR criteria: pressure, state, and response. The results showed that the salinity risk in the Yinchuan Plain was strongly influenced by the subsoil and groundwater salinity, land use, and depth to groundwater. To maintain agricultural sustainability in the Yinchuan Plain, a suite of remedial and preventative actions were proposed to manage soil salinity in the regions that are affected by salinity at different levels and by different salinization processes. The weight sensitivity analysis results also showed that the overall salinity risk of the Yinchuan Plain would increase or decrease as the weights for pressure or response risk factors increased, signifying the importance of human activities on secondary soil salinization. Ideally, the proposed method will help us develop more consistent management tools for risk assessment, management, and control of secondary soil salinization.