Imbalance between population growth and construction land expansion in the Mekong Delta, Vietnam: spatial-temporal analysis approach using a 1 km grid

Abstract The difference between population growth and the expansion of construction land is vital for sustainable development, especially in rapidly urbanizing coastal deltas like the Mekong Delta (MKD). This study assesses the population-land imbalance level in the MKD during two periods: 2000–2010 and 2010–2020. The assessment is done using the H index (human-land elasticity coefficient), the E index (construction land expansion differentiation index), and the PA index (average population growth rate), which are calculated on a 1×1 km grid. The results indicate that most of the study area did not achieve a balanced development state between population and urban land, with the situation being particularly severe in the 2010–2020 period. The H of most grid cells is outside the range of 0–1, reflecting that the rate of construction land expansion has far exceeded the rate of population growth. Uncoordinated regions are expanding and connecting into large spatial blocks, while coordinated areas are shrinking significantly. Additionally, E shows that the difference in the degree of land expansion intensity between subregions is becoming increasingly clear. Population trends also indicate an overwhelming increase in areas with low population growth rates during the 2010–2020. These findings reveal a severe imbalance between urban spatial development and population dynamics in the MKD, posing challenges to sustainable development goals and climate change adaptation. The study points out the need for integrated planning policies to adjust the pace of urban expansion in line with population trends, thereby improving land use efficiency and ensuring harmonious human-land development in the future.