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Students of physical geography do not commonly interrogate its nature and method, largely because they take the positivist approach for granted. Nor indeed has there been much consideration of how physical geography under the socio-economic, political and environmental circumstances of South Africa might influence its practice. This paper explores the identity and place of physical geography and compares the South African intellectual landscape with the situation globally. This is achieved through a brief analysis of publication patterns in The South African Geographical Journal in relation to the major international geography periodicals. It is concluded that physical geographers in South Africa, as is the case with their Anglo-American counterparts, have largely abandoned their identity as geographers per se. Instead, physical geographers increasingly present their work to a scientific audience where geographers are proportionally minor players. The hegemony of the international scientific publication industry has encouraged or even enforced the participation of physical geographers. Unlike in human geography, where there is a vibrant 'critical geography', physical geographers in South Africa have apparently failed to develop novel and fundamental theories and methods despite its remarkable, even unique, physical environmental circumstances. Nevertheless, a more integrated physical geography in South Africa has the opportunity to grapple with key environmental and socio-economic problems, including poverty, that have the potential to re-invigorate the discipline.

Fine particulate matter in the lower atmosphere (PM 2.5 ) continues to be a major public health problem globally. Identifying the key contributors to PM 2.5 pollution is important in monitoring and managing atmospheric quality, for example, in controlling haze. Previous research has been aimed at quantifying the relationship between PM 2.5 values and their underlying factors, but the spatial and temporal dynamics of these factors are not well understood. Based on random forest and Shapley additive explanation (SHAP) algorithms, this study analyses the spatiotemporal variations in selected key factors influencing PM 2.5 in Zhejiang Province, China, for the period 2000–2019. The results indicate that, while factors influencing PM 2.5 varied significantly during the period studied, SHAP values suggest that there is consistency in their relative importance as follows: meteorological factors (e.g., atmospheric pressure) > socioeconomic factors (e.g., gross domestic product, GDP) > topography and land cover factors (e.g., elevation). The contribution of GDP and transportation factors initially increased but has declined in the recent past, indicating that economic and infrastructural development does not necessarily result in increased PM 2.5 concentrations. Vegetation productivity, as indicated by changes in NDVI, is demonstrated to have become more important in improving air quality, and the area of the province over which it constrains PM 2.5 concentrations has increased between 2000 and 2019. Mapping of SHAP values suggests that, although the relative importance of industrial emissions has declined during the period studied, the actual area positively impacted by such emissions has actually increased. Despite developments in government policy, greater efforts to conserve energy and reduce emissions are still needed. The study further demonstrates that the combination of random forest and SHAP methods provides a valuable means to identify regional differences in key factors affecting atmospheric PM 2.5 values and offers a reliable reference for pollution control strategies.