Ecological Footprint Calculation of Beijing Based on Net Primary Productivity and its Comparison with Traditional Models

Ecological footprint method is widely used as an important measure of regional sustainable development. The traditional ecological footprint method has obvious deficiency and defect, for example, limitation of calculation, heavy artificial center, single land and single function, and the building land has same equilibrium factor with cultivated land. The ecological footprint theory is connected with net primary productivity to improve the traditional ecological footprint model and propose the ecological footprint model based on net primary productivity. The method had been applied to more than 100 countries in the world. The study intends to use the ecological footprint model based on net primary production to study the ecological footprint and ecological carrying capacity of Beijing from 2000 to 2010. The traditional ecological footprint model is calculated by biotic resources, which mainly involves the agricultural products, forest products, livestock products and aquatic products. All products correspond to cultivated land, forest land, grassland, and water area. In the ecological footprint model based on NPP, the main research objects of ecological carrying capacity include cultivated land, forest land, grassland, and water. The results are compared with traditional ecological footprint method. The results show that, the method greatly improves the equilibrium factor and yield factors of cultivated land, forest land, grassland and water. The equilibrium factors of forest land based on NPP were the highest, and the water's equilibrium factor was the lowest. The grass land's yield factor was the highest, and the other yield factor didn't change much. The ecological footprint and ecological carrying capacity of 4 kinds land has been improved compared with the traditional ecological footprint. The trend of ecological footprint based on NPP was the same as the traditional trend. But the trend of ecological carrying capacity was different: the results of NPP is 2005>2010>2000; the results of traditional is 2000>2005>2010. The traditional ecological footprint model was mainly based on statistical product production calculation, and it had more subjective, while the NPP method was based on actual productivity calculation.