为定量化描述南水北调来水对京津冀地区用水竞争力的影响，提出基于驱动增长率、刚性需水量、用水效益和用水紧缺程度等4项评价指标的用水竞争力指数模型，分析南水北调不同来水情景下京津冀地区的用水竞争力变化。结果表明：在南水北调来水与本地水联合供水情况下，京津冀地区3个行业的用水紧缺程度得到不同程度的缓解，行业刚性需水量均可得到满足，其中，生活用水紧缺程度降幅最大，工业次之，农业最小；与基准情景S0相比，各受水区在不同情景下的农业、工业和生活用水竞争力指数（water competitiveness index,WCI)平均减小17.3%，缓解了该区域的行业用水竞争压力；在不同来水情景下，京津冀地区用水竞争力指数呈现显著下降趋势，各情景下WCI值平均减小16.1%，区域用水竞争力分布呈现从环渤海湾区和河北南部地区双中心向河北南部单中心转变的特点。

Beijing-Tianjin-Hebei region is a political and economic center of North China,but its water resources per capita are less than one-tenth of the national average.Water resources competition caused by the contradiction between supply and demand has become a normal situation in this region.The phenomenon of water competition referred to the contradictions and conflicts in the use of water resources in terms of purpose,time and location.Due to water resources scarcity and uneven distribution,the disputes between the Guanting Reservoir and the Miyun Reservoir are the same.Given the limited water supply in this area,it is far from being able to meet the needs of regional development.Through the implementation of the South-to-North Water Transfer Project,China has transferred a part of the water resources from the abundant southern areas to the waterdeficient areas in the north.The goal is to alleviate the current outstanding water competition pressure.The transfer of a large number of externally transferred water sources has contributed to ensuring the sustainable development of the social economy and water resources of the Beijing-Tianjin-Hebei.But at the same time,it has also changed regional water supply and demand pattern,directly affecting water competition situation.Therefore,a quantitative analysis of the impact of the South-to-North Water Transfer Project on the competition of water resources in the Beijing-Tianjin-Hebei region is of great significance to ensure the rational use of regional water resources. The proposed water competitiveness mainly includes four parts;the main body of the competition,the demand for interests,the nature of the competition,and the objectives of the competition.If the existing water resources can not meet the water needs of all the main water users,the main water users had to obtain more and better water resources through competition to ensure basic production and domestic water use.This kind of water main body′s attraction and competition for water resources was defined as regional water competitiveness.The competitiveness of water use was inseparable from factors such as water driving factors,rigid demand,and water efficiency.Therefore,this study used driving growth rate,rigid water demand,water efficiency,and water scarcity as the four evaluation indicators of water competitiveness.The four evaluation indicators of each industry need to be calculated according to formulas to obtain different types of water competitiveness.Then the four evaluation indicators are standardized and substituted into corresponding formulas to calculate the water competitiveness index of each industry.Finally,the water competition index of each industry in the region was added to obtain the regional water competitiveness,to quantitatively analyze the size of the water competitiveness of each industry and region. Results showed that according to the set of multiple water scenarios (S1,S2,S3),the supply amount of a baseline scenario (S0) rose more than 20%,respectively,and BeijingTianjinHebei is tapping to Handan,Xingtai,phase ii of the eastern front in the (S3),there is still a large gap of water supply,after the completion of other local rigid demand in south-to-north water transfer supply.In addition,compared to S0 scenario,agricultural,industrial and domestic water competitiveness indices of Beijing-Tianjin-Hebei water-affected cities decreased by 10.6%,15.1%,and 26.1% on average under S1,S2,and S3 scenarios,and regional water competitiveness indices decreased by 11.5%,16.9%,and 19.8%,respectively.Among them,Tianjin and Beijing displayed the biggest decline in their comprehensive,with an average of 26.6%. Under the combined supply of water from the South-to-North Water Transfer project and the local water resources,the water shortage in the three industries of living,industry,and agriculture has been alleviated to varying degrees.The rigid water demand of all industries can be satisfied,and the domestic water shortage decreases the fastest,followed by industry and agriculture.Compared with the baseline scenario (S0),the industrial water competitiveness of each water supply area in Beijing-Tianjin-Hebei decreased by 17.3% and the regional water competitiveness decreased by 16.1% on average.In terms of space,the distribution characteristics have changed from a double center in the Bohai Bay Rim and southern Hebei to a single center in southern Hebei.In general,although the water transfer from the south-to-north does not eliminate the water resource competition problem in Beijing-Tianjin-Hebei region,it still greatly alleviates the water pressure,which is of great significance to the sustainable development of water resources and the optimal allocation of water resources in the region.