Seasonal and trend variation of methane concentration over two provinces of South Africa using Sentinel-5p data

Abstract

South Africa faces the urgency to comprehensively understand and manage its methane (CH₄) emissions. The primary aim of this study is to compare CH₄ concentrations between Eastern Cape and Mpumalanga regions dominated by cattle farming and coal mining industries, respectively. CH₄ concentration trends were analyzed for the period 2019 to 2023 using satellite data. Trend analysis revealed significant increasing trends in CH₄ concentrations in both provinces, supported by Mann-Kendall tests that rejected the null hypothesis of no trend (Eastern Cape: p-value = 8.9018e^-08 and Mpumalanga: p-value = 2.4650e^-10). The Eastern Cape, a leading cattle farming province, exhibited cyclical patterns and increasing CH₄ concentrations, while Mpumalanga, a major coal mining province, displayed similar increasing trends with sharper concentration points. The results show seasonal variations in CH₄ concentrations in the Eastern Cape and Mpumalanga provinces. High CH₄ concentrations are observed in the northwestern region during the December-January-February (DJF) season, while lower concentrations are observed in the March-April-May (MAM) and June-July-August (JJA) seasons in the Eastern Cape province. In the Mpumalanga province, there is a dominance of high CH₄ concentrations in southwestern regions and moderately low concentrations in the northeastern regions, observed consistently across all seasons. The study also showed an increasing CH₄ concentration trend from 2019 to 2023 for both provinces. The study highlights the urgent need to address CH₄ emissions from both cattle farming and coal mining activities to mitigate environmental impacts and promote sustainable development. Utilizing geographic information system (GIS) and remote sensing technologies, policymakers and stakeholders can identify and address the sources of CH₄ emissions more effectively, thereby contributing to environmental conservation and sustainable resource management.