南水北调工程通水缓解了受水区缺水状况，但考虑到非农用水的“促进效应”和农业用水的“返还效应”，其对受水区水资源非农化的影响存在不确定性。利用我国2003—2021年省级面板数据，构建多时点双重差分模型，从规模和程度双重视角定量分析南水北调工程通水对受水区水资源非农化的影响，并进行稳健性检验，在此基础上探究其累计效应。研究发现：南水北调工程通水显著提升受水区的非农用水规模和占比，且在稳健性检验后依然成立；机制分析表明，工程通水对受水区水资源非农化的影响主要体现在地表水和其他水供给量的增加；与东线工程相比，工程通水的影响在中线工程地区更为显著；细分来看，工程通水促进了工业用水规模的增加，同时农业用水规模逐步减少；此外，通水对受水区经济、社会和生态效益的影响分别体现在GDP增长、产业结构层次优化以及地表水和地下水变动率正向波动等方面。

Water is regarded as a fundamental resource for human society's development. China is recognized as one of the 21 most water-poor and water-scarce countries in the world. This is particularly evident in the Yellow River Basin, where there is a significant imbalance between water supply and demand. To mitigate the water scarcity in the northern region, China constructed the South-to-North Water Transfers Project (SNWTP), thus representing a cross-basin and cross-regional water resources allocation initiative. The severe water shortage predicament in the receiving areas was notably improved by the opening of both the central and eastern routes of the SNWTP. Furthermore, as China progressed with its industrialization and urbanization, a substantial portion of agricultural water was redirected towards non-agricultural purposes, thereby driving an ongoing increase in non-agricultural water demand. Considering the exogenous impact of the SNWTP, it had the potential to either stimulate or hinder the non-agriculturalization of water resources in the receiving areas, while simultaneously addressing water resource constraints. As a result, to empirically investigate, the precise impact of the opening of the SNWTP on the non-agriculturalization of water resources in the receiving areas remained uncertain and warranted further investigation. The impact of the opening of the SNWTP on the non-agriculturalization of water resources in the receiving areas is assessed in terms of scale and degree using a time-varying differences-in-differences model based on provincial panel data from the year 2003 to 2021. Robustness tests such as parallel trend test, placebo test, exclusion of other policy interferences, propensity score matching, controlling for time trend, heterogeneity treatment effect and Bacon decomposition are conducted on this basis. The opening of the SNWTP has been shown to have a positive impact on both the scale and degree of non-agricultural water resource use in the receiving areas. Robust tests have confirmed that this conclusion is consistently valid. The primary mechanism behind this effect is the increase in surface water and other water supplies, while the impact on groundwater was found to be negligible. Furthermore, significant regional differences exist in how the SNWTP influences non-agricultural water resource use. The project has a notably stronger effect on the central route compared to the eastern route. Additionally, the specific impacts of the project include an increase in industrial water usage and a decrease in agricultural water usage. Over time, the cumulative effects of the SNWTP on the de-agriculturalization of water resources in the receiving areas are evident in GDP growth, an increase in the hierarchical coefficient of the industrial structure, and positive changes in both surface and groundwater levels. It is recommended to strengthen the rational use of non-agricultural water to promote industrial development. Surface water protection should be strengthened and a sound water resources management system should be established. The water resource management in the central line area should be strengthened and the cross-border management of water resources should be promoted. Finally, the structure of industrial water use is optimized, the management of domestic water use is strengthened, the ecological protection and restoration is reinforced, and the efficiency of agricultural water use is improved. The empirical evidence provided by the findings of this paper can be used to promote the high-quality development of the SNWT follow-up project. Further exploration could be conducted in follow-up studies regarding the impacts of the SNWTP on quality and efficiency issues of non-agricultural water use in the receiving areas, the long-term impacts of the SNWTP on local ecosystems, and the impacts of the SNWT on food security.