Response of Domestic Water in Beijing to Climate Change

Abstract

Beijing, a megacity in northern China, has been long facing the challenge of water scarcity, and the problem of domestic water scarcity has been becoming more serious in recent years due to climate change and global warming. To cope with the adverse effects of climate change, it is urgent to build a prediction model for water consumption in Beijing under the background of climate change. Here, a climate domestic water use model was established based on the historical meteorological data and domestic water use data, and the future domestic water demand in Beijing and the response of domestic water use to climate change were projected. The results showed that the climatic water consumption in Beijing will increase with climate warming by 177.23 million m3/°C, and the per capita annual water consumption will increase by 8.1 m3/°C. Combined with the CMIP6 multi-model climate change scenario data, the climate domestic water consumption in Beijing in 2035 under the four scenarios of SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 will be 169 million m3, 189 million m3, 208 million m3, and 235 million m3 respectively; by 2050, the climate domestic water consumption in Beijing will reach 338 million m3, 382 million m3, 395 million m3, and 398 million m3, respectively. Under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, if all the increased climate domestic water consumptions are supplemented by groundwater, compared with 2019, the groundwater depth will decrease by 0.18 m, 0.22 m, 0.27 m, and 0.32 m in 2035, respectively, and the area of funnel area will increase by 6.84 km2, 8.48 km2, 10.11 km2, 12.34 km2 respectively. Compared with 2035, the groundwater depth in 2050 will decrease by 0.37 m, 0.43 m, 0.41 m and 0.36 m, respectively, the area of funnel area will increase by 14.13 km2, 16.21 km2, 15.61 km2, and 13.68 km2, respectively. If the increased climatic water consumption in Beijing is supplemented by external water transfer, the cost of external water transfer in 2035 will increase by CNY 391 million, CNY 485 million, CNY 578 million, and CNY 706 million, respectively, compared with that in 2019 under the four scenarios. Compared with 2035, the cost of external water transfer in 2050 will increase by CNY 808 million, CNY 927 million, CNY 893 million, and CNY 783 million, respectively.