Urban watershed runoff evolution and the response under changing environment

Basin runoff is an important response factor to changing environment. Under the influence of climate change and human activities, watershed runoff has undergone profound changes. Studying its evolution and response characteristics is helpful to improve human’s ability to cope with changing environment. Taking the main catchment area of the Beijing municipal area of the North Canal as the study area, the variation trend of rainfall and runoff in the North Canal basin was analyzed by analyzing the hydrological data of hydrometeorological observation stations in the past 40 years, and the flood field was extracted. The global climate model data is introduced, the downscaling model is used for downscaling, and the runoff forecast is analyzed in combination with the hydrological model. The results show that the historical precipitation trend of the basin is not obvious, and the runoff is increasing. In the future, the change of water resources in the North Canal Basin (Tongxian Station) will be more obvious under the influence of climate change. With the increase of temperature and precipitation, the runoff will increase, and the discharge is predicted to reach a new high of 385.1m³/s in the middle of this century. With the continuous increase of radiative forcing, the degree of hydrological response increases correspondingly, and most of the peak runoff in the North Canal basin occurs in the late 2050 and 2090 periods. The research can provide some reference for the future water resource utilization, flood containment and disaster reduction measures and the realization path of dual carbon targets in urban watershed.