First Author: SHAO Weiwei
Corresponding Author: LI Yuxing
Journal: Journal of Cleaner Production
The prediction of future rainwater resources plays a key role in assessing the potential impacts of rainwater utilization on natural and social systems. However, research on the impact of climate change on future rainwater resources remains insufficient, particularly with respect to large-scale water diversion projects. This study, based on global climate model data, future land use data, and the SCS-CN (Soil Conservation Service Curve Number) model, proposes a method for evaluating rainwater resources potential under multiple climate change scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5).
The method is applied to the water-receiving areas of the South-to-North Water Diversion Project for analysis. The results indicate that:
(1) The annual potential of rainwater resources in the studied area from 2021 to 2100 shows a growth trend, with a spatial distribution characterized by higher levels in the south and lower levels in the north. Under the SSP5-8.5 scenario, the water-receiving areas of the eastern route project increase by more than 70% compared with the baseline period in 2020, with significant growth observed in the city clusters in northern Jiangsu Province.
(2) Future spatial distribution patterns of rainwater resources exhibit normal distribution with single peak in the water-receiving areas of the east- and west-route projects, while the water-receiving areas of the central route project display prominent bimodal features.
(3) Based on fitting with the Pearson type III distribution curve, the potential of rainwater resources in the studied areas under different assurance rates in the future is as follows: 5.06 × 1010 m3 at P=25%, 3.53 × 1010 m3 at P=50%, and 2.46 × 1010 m3 at P=75%.
This study provides a case for quantifying the uncertainty of rainwater potential under climate change, and also offers reference for the construction and scheduling schemes of large-scale water diversion projects worldwide.
Keywords: Climate change; CMIP6; South-to-North Water Diversion Project; Rainwater resources
