Demand-driven water withdrawals by Chinese industry： a multi-regional input-output analysis

With ever increasing water demands and the continuous intensification of water scarcity arising from China＇s industrialization, the country is struggling to harmonize its industrial development and water supply. This paper presents a systems analysis of water with- drawals by Chinese industry and investigates demand- driven industrial water uses embodied in final demand and interregional trade based on a multi-regional input-output model. In 2007, the Electric Power, Steam, and Hot Water Production and Supply sector ranks first in direct industrial water withdrawal （DWW）, and Construction has the largest embodied industrial water use （EWU）. Investment, consumption, and exports contribute to 34.6%, 33.3%, and 30.6% of the national total EWU, respectively. Specifically, 58.0%, 51.1%, 48.6%, 43.3%, and 37.5% of the regional EWUs respectively in Guangdong, Shanghai, Zhejiang, Jiangsu, and Fujian are attributed to international exports. The total interregional import/export of embodied water is equivalent to about 40% of the national total DWW, of which 55.5% is associated with the DWWs of Electric Power, Steam, and Hot Water Production and Supply. Jiangsu is the biggest interregional exporter and deficit receiver of embodied water, in contrast to Guangdong as the biggest interregional importer and surplus receiver. Without implementing effective water- saving measures and adjusting industrial structures, the regional imbalance between water availability and water demand tends to intensify considering the water impact of domestic trade of industrial products. Steps taken to improve water use efficiency in production, and to enhance embodied water saving in consumption are both of great significance for supporting China＇s water policies.

STRATEGIES FOR A LOW-CARBON FOOD SYSTEM IN CHINA

In China,there has been insufficient study of whole food system greenhouse gas(GHG)accounting,which limits the development of mitigation strategies and may preclude the achievement of carbon peak and carbon neutrality goals.The paper presents the development of a carbon extension of NUFER(NUtrient flows in Food chain,Environment and Resources use model),a food system GHG emission accounting model that covers land use and land-use change,agricultural production,and post-production subsectors.The spatiotemporal characteristics of GHG emissions were investigated for the Chinese food system(CFS)from 1992 to 2017,with a focus on GHG emissions from the entire system.The potential to achieve a low-carbon food system in China was explored.The net GHG emissions from the CFS increased from 785Tg CO_(2)equivalent(CO_(2)-eq)in 1992 to 1080 Tg CO_(2)-eq in 2017.Agricultural activities accounted for more than half of the total emissions during the study period,while agricultural energy was the largest contributor to the GHG increase.In 2017,highest emitting regions were located in central and southern China(Guangdong and Hunan),the North China Plain(Shandong,Henan and Jiangsu)and Northeast China(Heilongjiang and Inner Mongolia)and contributed to over half of the total GHG emissions.Meanwhile,Xinjiang,Qinghai and Tibet are shown as carbon sink areas.It was found that foodsystem GHG emissions could be reduced to 355 Tg CO_(2)-eq,where enhancing endpoint mitigation technologies,transforming social-economic and diet conditions,and increasing agricultural productivities can contribute to 60%,25%and 15%,respectively.Synergistic mitigation effects were found to exist in agricultural activities.