基于净初级生产力的中国生态足迹均衡因子测算

The Calculation of China's Equivalence Factor under Ecological Footprint Mode Based on Net Primary Production

生态足迹作为一种非货币化的生态系统评估工具,是近年来国际上一种重要的判别可持续发展程度的生物物理量方法。均衡因子是生态足迹计算中的一个重要参数,它将6种生物生产性土地类型的面积转换为具有相同生物生产力的面积,从而实现了6种类型土地面积的加和,因此,均衡因子是否准确直接影响到计算结果的可靠性与可比性。随着生态足迹方法的广泛应用,其标准化和本地化研究成为迫切的需要。论文采用中国2001年1 km MOD IS数据,根据植被的净初级生产力,对中国的平均均衡因子进行了测算:耕地和建筑用地为1.71,林地和能源用地为1.41,草地为0.44,水域为0.35,并与国际通用的均衡因子进行了对比。

Ecological footprint （ EF）, as a kind of physical indicator to measure the extent of humanity＇ s use of natural resources, has been one of the most successful methods to assess sustainable development, and has gained much attention both at home and abroad since it was developed by Wackernagel and Rees in 1996. In order to sum up different area types with different productivities, equivalence factor was introduced to relate the different types of land （ i. e. cropland, pasture, forest, average primary biomass productivities of fishing ground） to the regional average primary biomass productivity of all land types in a given year. So, equivalence factor is an important parameter in EF model and it directly affects the reliability of the result. This article calcu- lates China＇ s average equivalence factor based on net primary production （NPP） from MODIS 1 km data in 2001. Firstly, a detailed land cover classification system from MODIS data is designed based on the six area types of the EF account, it includes 21 types and almost covers all kinds of ecosystems in China; secondly, based on the Light Utility Efficiency and CASA model, a model is set up to estimate the NPP of China, which a 1 km Chinese land cover MODIS data are used as main remote sensing data input in it, and the authors estimate the plant productivity of China in 2001 ; then the China＇ s equivalence factor of six area types is calculated based on NPP, cropland and built-up land have an equivalence factor of 1.71, forest area and ＂energy＂ land have a factor of 1.41, grazing land has a factor of 0. 44 and fishing ground of 0. 35. Based on the above analysis, this article gives the equivalence factors of different ecosystems in China, mixed forest has a biggest equivalence factor of 2. 17, and glacier has a smallest factor of 0. 02. Finally, authors compare the equivalence factors between China and the world, and find that China＇ s equivalence factor is similar to the world＇s factor, but the factor of cropland in China is a little smaller than the world＇s average level.