Multi-temporal assessment of land-condition change around Shwan Refinery Iraq using Landsat observations and soil metal evidence

This study assesses land-condition change around Shwan Refinery, Iraq, using 79 Landsat 8 Collection 2 Level-2 scenes covering fourteen summers (2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022)(2023)(2024)(2025)(2026) and twenty secondary soil-metal records.QA-masked summer medians were summarized on common valid support in five distance zones extending 10 km from an internal reference point.First-zone descriptive Theil-Sen slopes of annual means were +0.002066 per year for NDVI, +0.000703 for NDMI, -0.001015 for BSI and -0.009243°C per year for LST.Negative pixel-level NDVI slopes occurred in 23.29% of common first-zone cells.The four-sign screening condition-declining NDVI and NDMI with rising BSI and LST-occurred in 6.27% of first-zone cells and 9.48% of outermost-zone cells; these are not validated degraded areas.NDBI equals -NDMI and supplies no independent confirmation.Year-omission checks retained positive NDVI and negative BSI first-zone mean slopes, but their magnitudes were sensitive to 2026; NDMI and LST signs changed.Original spatial omission maps identified mixed NDVI signs in 57.20% of first-zone cells.Conditional residual block-bootstrap tests found no significant trend after Holm adjustment across 20 indexzone series at block lengths of two, three or four years.Summer NDVI covaried with antecedent rainfall (Spearman rho = 0.8505).Soil associations remained exploratory, without calibrated metal prediction or repeat chemical measurements.The evidence indicates heterogeneous surface change but does not establish generalized persistent degradation caused by refinery operations, exclude an industrial contribution or demonstrate environmental safety.Short-series uncertainty, climate covariation, spatial dependence and limited soil sampling constrain interpretation.