Spatial-temporal change of ecological supply and demand based on a modified model of ecological footprint in Hebei Province, China

Ecological footprint (EF) methodology is essential for quantifying humanity's consumption of natural capital. Considering the impact of the freshwater (especially the groundwater) resource on industrial and agricultural production and people's daily life, freshwater resource was added to the conventional EF calculation as a new account, and then the EF model was improved by introduction of the multiple cropping index. Based on the improved EF model, ecological supply and demand and their spatial-temporal variation in Hebei Province in recent 10 years (2000-2009) were analyzed. The results showed that the ecological economic system of Hebei was relatively unsustainable, and the total EF, ecological capacity and ecological deficit (ED) have an increasing trend in recent 10 years. Tangshan city has the most serious ecological deficit among the 11 cities, and fossil energy land was the most serious factor which restricts the sustainable development of Hebei. In recent years, the utilization ratio of resources has increased gradually, and the total requirement of ecological resources was increasing, but the dependence level of the resources for the development of economy has reduced in Hebei.