Standardized method for material flow data collection at city level

The collection of material flow data is the first step in the evaluation of the circular economy performance and material metabolism at the city level. However, Chinese statistical data are published by Chinese National Bureau of Statistics, and provincial and municipal Bureau of Statistics. This resulted in data being scattered in dispersed sources and varying between cities, even brings about mistakes. Therefore, we established a standardized data collection and accounting method with regular data sources for Chinese cities. In this data collection method, material flow accounting mainly consists of three parts: direct material input, material recycling, and waste disposal. It covers four types of materials, including fossil fuels, biomass, metal minerals, and non-metallic minerals with 155 items. We combined the data sources for the material flow accounting within a standardized Excel spreadsheet with detailed information on statistical data sources and equations to convert the information into material flow data. The statistical data were derived from the China City Statistical Yearbook, the provincial Statistic Yearbook, and the city's statistical yearbook. The estimated data in the material accounting were obtained by converting statistical data using relative coefficients. According to the main sources and features of materials use, the intersectoral material flows can also be estimated following this standardized method for urban metabolism analysis, circular economy performance evaluation, and ecological network analysis. The standardized method for material flow data collection was adopted in the article “H. Gao, X. Tian, Y. Zhang, L. Shi, F. Shi, 2021. Evaluating circular economy performance based on ecological network analysis: A framework and application at city level. 105257. Resources, Conservation & Recycling. https://doi.org/10.1016/j.resconrec.2020.105257”.