Impact of Climate Change on Water Resources in the Western Route Areas of the South-to-North Water Diversion Project

The South-to-North Water Diversion Project (SNWDP) is a national strategic project for water shortages in northern China. Climate change will affect the availability of water resources in both source and receiving areas. A grid-based RCCC-WBM model based on climate projections from nine Global Climate Models under SSP2-4.5 was used for analyzing the changes in temperature, precipitation, and streamflow in the near future (2025-2045, NF) and far future (2040-2060, FF) relative to the baseline (1956-2000). The results showed that: (1) the temperature of the western route will increase significantly in the NF and FF with an extent of 1.6 degrees C and 2.0 degrees C, respectively, (2) precipitation will very likely increase even though Global Climate Model (GCM) projections are quite dispersed and uncertain, and (3) over half of the GCMs projected that streamflow of receiving area will slightly increase with a rate of 1.68% [-8.67%, 12.3%] and 2.78% [-3.30%, 11.0%] in the NF and FF, respectively. Climate change will support the planning of the western route to a certain extent. However, water supply risk induced by the extreme situation of climate change should be paid adequate consideration when the project operates in practice due to the large dispersion and uncertainty of GCM projections.