Spatial economic modelling of flood-induced salinisation: Quantifying losses and economy-wide spillovers in coastal agri-food systems

Flood-induced salinisation poses a significant threat to agricultural productivity and economic stability, particularly in flood-prone regions like Greater Lincolnshire, United Kingdom, where agriculture contributes substantially to the local economy. This study assesses the impacts of salinisation on crop production value and its cascading effects on the broader economy, employing spatial econometric models, propensity score matching (PSM), regression analysis, and Leontief input-output frameworks. Focusing on key crops such as winter/spring wheat/barley, beet, oilseed, and potato, the study integrates spatial data on crop distribution, land quality, and flood zones to model salinity effects. Results reveal strong spatial spillovers, with land quality and crop area as dominant predictors of value losses, while salinity's direct impact is minimal, suggesting effective adaptations or confounding factors. PSM ensures robust causal inference, showing excellent covariate balance for most crops, though potato exhibits some imbalances. Economy-wide analysis indicates total losses exceeding £253 million for the chosen crops, with £124 million for winter wheat alone, with ripple effects through supply chains, including wholesale trade and fertilizer sectors. Sensitivity simulations highlight systemic vulnerabilities to shock magnitudes. The findings underscore the need for spatially targeted policies, such as enhanced drainage and salt-tolerant crop promotion, to mitigate clustered risks and ensure food resilience. Future research should incorporate dynamic models and comparative studies to address methodological limitations and enhance predictive accuracy.