Copper in-use stocks accounting at the sub-national level in China

Abstract

Copper in-use stocks play an important role in copper cycle. Investigating copper in-use stocks is essential to realize more efficient and sustainable utilization of copper resources. A systematic analysis at the sub-national level is still inadequate, especially for those sub-regions of the studied area. In order to fill the research gap, this study uses Chinaös Sichuan Province as a case to assess copper in-use stock and its spatial distribution at the sub-national level in China. Employing a bottom-up modelling approach, this study calculates the copper in-use stocks in Sichuan and its 21 prefectural sub-regions in 2014. Our results show that, 1) copper in-use stocks of the whole province were 1,891 Gg and the amount of in-use stocks per capita was 23 kg, which is far below the level of the developed countries and implies significant growth potential in the future. 2) Among all the categories calculated, residential buildings, non-residential buildings, automobiles, air conditioners, power substations, refrigerators, power transmission and distribution cables were the main reservoirs of copper and collectively took nearly 80% of the total stocks. Stocks per capita for the prefectural sub-regions in Sichuan are relatively close, ranged from 17.1 to 28.8 kg. 3) Distinction between rural and urban copper in-use stocks indicates Sichuanös rural copper stocks occupy an indispensable proportion. 4) The stocks density for prefectural regions varied from 149 kg/km2 to 34,302 kg/km2, indicating significant imbalance of spatial distribution characteristic and an unignorable intra-provincial disparity.