Are the drylands in northern China sustainable? A perspective from ecological footprint dynamics from 1990 to 2010.

The drylands in northern China (DNC), characterized by water scarcity, high climatic variability, and infertile soil, are crucial for China's sustainable development in the context of rapid urbanization. However, few studies have systematically investigated its sustainability. Our objective was to assess the sustainability of the DNC according to their ecological footprint (EF) dynamics from 1990 to 2010. We analyzed EF in the DNC at multiple scales ranging from the whole, to four dryland subtypes, to the drylands in each province. We found that the total EF in the DNC increased from 3.48 × 10(8) global hectares (gha) in 1990 to 1.26 × 10(9) gha in 2010, with a growth of 2.63 times, resulting in a more than 14 times increase of ecological deficit from 6.26 × 10(7) gha to 9.63 × 10(8)gha. In addition, the water withdrawal increased from 133.29 km(3) to 153.23 km(3) with a growth rate of 14.96%, while the Human Development Index grew from 0.62 to 0.79. We concluded that the DNC has already become unsustainable after the rapid increases of EF and water withdrawal from 1990 to 2010. We argue that effective management is needed to maintain and improve the environmental sustainability of the DNC.