Raveling the nexus between urban expansion and cropland loss in China

ContextThe dramatic expansion of urban lands has caused widespread cropland losses in China, yet little evidence is given on the progress of such transformation spatial-temporal explicitly.ObjectivesThe present study aims to disentangle the underlying interaction between urban expansion and cropland loss as well as its socioeconomic drivers and future trends.MethodsWe analyzed the extent of cropland loss resulting from urban expansion among different regions and city tiers using China's annual land cover datasets. We then introduced the Environmental Kuznets Curve hypothesis to examine the relationship between such progressive changes and economic growth through panel data regressions. By combing the future urban land expansion datasets, we further estimated the pressure of potential cropland loss under five shared socioeconomic pathways.ResultsUrban expansion directly led to a loss of 12 Mha croplands during 1990-2019. Nearly 84% of newly built urban lands occurred on croplands, with higher-tier cities experiencing more severe and direct losses. There exists an inverted-U shape relationship between cropland-urban land conversion and economic factors in China. Most 1st, newly 1st, and 2nd tier cities followed this decoupling pattern while some of the lower-tier cities were characterized by the increase or decline mode. It is estimated that 3.9-4.9 Mha of the existing croplands will be replaced by future urban land expansion by 2050, where 2nd and 3rd tier cities will have the greatest loss in terms of accumulative area.ConclusionsThese findings highlight the important role of land use transition and adaptive planning policies in ensuring food security and achieving sustainable development goals.

Automated summary

The dramatic expansion of urban lands in China has resulted in widespread cropland losses. This study examines the interaction between urban expansion and cropland loss, identifying socioeconomic drivers and future trends. The results show that urban expansion directly led to the loss of 12 million hectares of croplands during 1990-2019. There is an inverted-U shape relationship between cropland-urban land conversion and economic factors in China. It is estimated that 3.9-4.9 million hectares of existing croplands will be replaced by future urban land expansion by 2050, with second and third tier cities experiencing the greatest loss.