Climate change and Land Use/Cover Change, affected by human activity, are the two main factors influencing the regional water cycle and water management. However, studies of co-impacts based on future scenario predictions are still lacking. This study proposed a complete methodology for simulating future changes in water resources and distinguishing the independent and synergistic effects of climate change and land use change. The coupling prediction model of land use and the global climate models were used for scenario predictions; the hydrological model and statistical methods were used for simulations and analyses. The Ganjiang River, the largest tributary of Poyang Lake, is chosen as the study area. In the future, the main trend of change in land use would be the expansion of construction land in the northern part of the basin, and the future annual precipitation and temperature (p < 0.5) would increase. In this basin, runoff is more sensitive to climate change than to land use/cover change, and the synergistic effects are not substantial. Most climate scenarios showed a significant change in monthly peak runoff. The current peak is in June; this is projected to decrease with the simulated future peak in August, causing problems in basin flood control and Poyang Lake water level regulation. This study proposed a methodology integrating the global climate models with predicted land use scenarios and tested the feasibility at the watershed scale by the case study. It can serve as a reference for co-impact studies considering different scenarios and be extended to basins with similar areas, underlying surface variation intensity, or hydro-climatic characteristics, valuable for sustainable water resources management in the Anthropocene.

受人类活动影响的气候变化和土地利用/覆盖变化是影响区域水循环和水资源管理的两个主要因素。然而，仍然缺乏基于未来情景预测的共同影响研究。本研究提出了一套完整的方法来模拟未来水资源的变化，并区分气候变化和土地利用变化的独立和协同效应。利用土地利用耦合预测模型和全球气候模型进行情景预测；水文模型和统计方法被用于模拟和分析。鄱阳湖最大支流赣江被选为研究区。未来土地利用变化的主要趋势是流域北部建设用地扩张，未来年降水量和温度（p < 0.5）会增加。在这个流域，径流对气候变化比对土地利用/覆盖变化更敏感，协同效应并不显着。大多数气候情景显示每月峰值径流发生显着变化。目前的高峰是在六月；预计随着8月份模拟的未来高峰期而减少，导致流域防洪和鄱阳湖水位调节出现问题。本研究提出了一种将全球气候模型与预测的土地利用情景相结合的方法，并通过案例研究在流域尺度上测试了可行性。它可以作为考虑不同情景的共同影响研究的参考，并扩展到具有相似面积、下垫面变化强度或水文气候特征的流域，