Patterns and drivers of population in the borderlands of Mainland Southeast Asia

Abstract

Population concentration is a visible manifestation of the spatial pattern of demographic distribution, exerting significant impacts on local socio-economic and natural environment. Currently, population-analysis mainly focuses on administrative units, with limited attention given to borderlands characterized by rapid changes and complex geopolitical and economic environment, let alone drivers. Here, based on WorldPop (100 m and 1 km) datasets, we take population agglomeration index (PAI), population change amplitude (PCA), and relative change in population density (RCPD) as the three main indicators, use GIS spatial analysis and mathematical statistics to quantify the spatio-temporal patterns of population in the borderlands of Mainland Southeast Asia (MSEA) during 2000–2020, and then reveal the underlying mechanisms through the geographical detectors. The result indicated population growth in the borderlands of MSEA has accelerated over the past 21 years. This growth has contributed to over 20% of the total population increase across the entire MSEA, and its increase amplitude is more than twofold. The population pattern of the borderlands is characterized by an increasing trend towards agglomeration, with spatio-temporal heterogeneity and significant country differences, particularly Cambodian. The drivers of population agglomeration in the MSEA's borderlands are dominated by natural environmental conditions, with land cover having the highest explanatory power for population agglomeration, especially cropland and forest. Understanding the border-prone characteristics of population and potential mechanism in MSEA can provide a reference base for local sustainable development and geopolitical and economic environmental changes in the borderlands, and promote the development of population geography.