The University of Tokyo · Engineering
Professor Cheng-Yao Zhang's research lab focuses on sustainable water and resource management, with a strong emphasis on optimizing water allocation in large river basins such as the Yellow River. The lab integrates systems analysis, life cycle assessment (LCA), and game-theoretic modeling to evaluate environmental performance and policy effectiveness in agricultural water pricing, chemical recycling, and vertical farming. Key research directions include climate impact assessment of plastic recycling, carbon circularity in waste management, and multi-objective water resource allocation under scarcity and economic development pressures.
Figures are computed from collected data and may differ slightly.
Strengthening water resource management and improving water-use efficiency are crucial for sustainable development, as described in the Target 6.4 of the Sustainable Development Goals. Compared with developed countries, developing countries are facing some general obstacles on agricultural water management from policy making, pricing mechanisms, infrastructure, and subsidy implementations, which has left developing countries with little progress in improving agricultural water management through
Chemical recycling systems have been reported to enhance the environmental performance of plastic waste management. Life cycle assessment (LCA) has been extensively employed to evaluate the potential environmental benefits of chemical recycling compared with other recycling systems. However, a disparity exists between the outcomes of environmental assessments and the anticipated environmental benefits of chemical recycling. Moreover, few reviews have discussed the findings of these comparable st
Competitions and disputes between various human water sectors and environmental flow of the river are exacerbated due to the rapid growth of the economy in Yellow River basin as well as the limited supply of available water resources in recent decades. It is necessary to implement rational and effective management and allocation to alleviate the pressure of water shortage. In order to promote economic development and maintain the ecological balance of the river, both the water allocation to the
Optimizing water allocation is a crucial strategy for water planning in large basins, such as the Yellow River basin. The transforming water supply pattern, triggered by inter-basin water transfer, urges the optimization and refinement of water allocation. Here, we predict the future water demand for different sectors at the provincial level and carry out future water allocation based on a multi-objective allocation model. The results imply that "demand increases in midstream and water deficits
Vertical farm (VF) is hailed as a hope for a sustainable food supply system. Fruiting vegetable production is being incentivized in this industry to diversify the product offerings. However, this production model has yet to receive substantive evaluations on environmental performance. This study conducted experiments and employed life cycle assessment (LCA) to evaluate the environmental performance of tomato production in VF, comparing it with tomato production in high-tech greenhouses and lettu
Carbon circularity has attracted increasing attention alongside climate change impacts and fossil energy consumption in plastic recycling evaluations. Herein, we introduce the carbon flow and circular diagram (CFCD) method, a unified framework designed to assess plastic recycling by integrating carbon circularity, carbon neutrality, and fossil energy independence. CFCD visualizes carbon flows by mapping carbon inputs and outputs across various pathways. We apply our approach to the complex ecosy
Circularity is considered to be pivotal for achieving carbon neutrality in plastic waste management. This study evaluated various recycling and recovery options for plastic packaging waste (PPW) in Japan, including circular and one-way chemical recycling. Using life cycle assessment, we examined these options in terms of fossil resource consumption and climate change impacts, categorizing fossil resources into coal, oil, and natural gas. All the evaluated options provide fossil energy benefits,
Open papers in the app to read, cite, and organize with AI.