Water Saving And Air Pollution Mitigation In China

At the global scale,water shortage and air pollution have presented significant challenges to achieving Sustainable Development Goals(SDG)of United Nations.China is one of the many nations,which suffers from severe water scarcity and air pollution,meanwhile accommodating 18% of the total population globally.Therefore,it is an urgent task for China to save water resources and to mitigate air pollution.The Chinese government has released the most stringent policies,e.g.Air Action Plan 2013 and Water Action Plan 2015,committing to reducing the PM concentration and to improving water use efficiency.Despite favorable effects of these policies and measures to achieve local targets,unintended consequences should not be overlooked when spillover effects occur.One typical example is that the trade activities are driven by comparative advantage,policies and other factors,resulting in the displacement of environmental impacts or resource depletion between production and consumption.As a result,trade activities are not necessarily in favor of achieving the national targets.Similarly,the industrial production relocation among regions would cause the relocation of air pollution relocation as well.Therefore,this dissertation researcher aims to evaluate the displacement of environmental impacts(water use or air pollution)virtually or physically.Results will provide new insights to effectively achieve the goals in water saving or air pollution mitigation.Water was embodied in traded goods,i.e.“virtual water trade”(VWT),which was largely influenced by global and regional trend of fragmentation in production.Focusing on the watereconomic system in the first study,this dissertation researcher aimed to examine how production fragmentation affected the inter-regional spillover of water uses(measured by VWT)driven by goods production,consumption and trade activities.The author of this dissertation used China's multi-regional input-output(MRIO)tables to trace the trade of a given region's three types of goods: local final goods,local intermediate goods,and goods that were shipped to other regions and countries(i.e.value chain-related trade).Based on an improved MRIO method,analytical results attributed the water consumption to different stages of production along the supply chain for each province.This research identified the inter-regional spillover of water uses and the contribution of different types of trade to the spillover.Unfortunately,results indicated that national water use increased due to trade,with value chain-related trade as the largest contributor to the increase.Thus,opportunities for regional and national water use savings were identified in terms of specific regions,sectors and trade types.These findings underscored the necessity of incorporating trade types in developing specific policies for allocating water resources as well as promoting water conservation.Energy sector was a major water consumer,and played an important role in national and local water savings,as described in the first study.Its water use,as one aspect of energy-water nexus(i.e.“water for energy”)was examined in the second study in this dissertation to explore potential vulnerability of energy and water uses relevant with spillover effects due to trade(measured by VWT).The water footprints were analyzed for the entire supply chain driven by energy demand sourced locally and externally,so as the water implications.Five types of energy demand in China were covered.By applying an Environmental Extended MRIO method,this research calculated the(scarce)water footprints driven by energy demand and the degree of reliance on scarce water,indicating the vulnerability of energy demand to water scarcity in coastal and northern provinces.Hotspots were identified for those facing physical or holistic water scarcity but exporting virtual(scarce)water,such as Yellow River Region and Northeast Region.To mitigate water shortage driven by energy demand,interprovincial flows and sectors needed to be differentiated based on the energy demand.In addition,two energy sources scenarios were assumed and the(scarce)water saving potential was examined.It was necessary to take the transboundary water impacts(inter-regional spillover effects)associated with energy demand into account to achieve energy security and water saving.A top-down approach was adopted from the domestic supply chain perspective in the first and second study.In contrast,the third study attempted to examine the spillover effects of regional policy on air pollution from a plant-level behavior perspective following a bottom-up approach.Focusing on the iron and steel industry in China,the author of this dissertation developed a production relocation database,to establish a unit-based bottom-up model for estimating the industrial upgrade performance and air pollution mitigation potential for each city and process because of the production relocation.Results showed that the production relocation helped to achieve the air pollution mitigation at both local and overall scale,but with limited spillover of air pollution to other regions,in contrast with that in the first study.This highlighted the critical role of adopting energy saving technologies and stricter emission limits during the production relocation to achieve the national overall mitigation target,and presented a promising case for inter-city cooperation.An integrated framework was developed in this dissertation to assess the environmental impacts derived from production relocation.Opportunities were identified to achieve both national and regional target on air pollution mitigation by relocating heavy industries,especially in emerging economies.