水源涵养能力是生态系统服务功能的重要体现，为探究变化环境下的流域水源涵养状况，支撑流域生态保 护和经济发展，构建沁河流域 SWAT（soil?and?water?assessment?tool）模型，基于元胞自动机马尔科夫（celluar automata-Markov，CA-Markov）模型预测未来 2030 年土地利用状况，结合第六次国际耦合模式比较计划 (coupled model?intercomparison?project?phase?6，CMIP6)?气象数据，模拟流域未来降水、蒸发和径流，依据水量平衡原理，分 析历史和未来年份流域水源涵养能力的时空变化特征。时间维度上：2010—2016 年沁河流域水源涵养能力呈波 动上升趋势，多年平均水源涵养量为 49?mm，多年平均水源涵养率为 8%；2024—2030 年水源涵养能力呈波动下降 趋势，多年平均水源涵养量为 51?mm，多年平均水源涵养率为 10%。空间维度上：2010、2015 和 2025 年流域水源 涵养能力呈现从上游到下游递增的趋势，2030 年则呈现从上游到下游递减的趋势。整体来看，流域多年平均水源 涵养量不足 100?mm，且各年份均有子流域的水源涵养量出现负值，流域水源涵养能力较差。研究结果可为流域 水资源管理、协同保护和发展以及改善人水关系提供科学参考和数据支撑。

In the context of global climate change, excessive deforestation, urban construction and irrational use of water resources have been carried out by human beings for a long time, and the phenomena of water resource shortage, water environment pollution, water ecology deterioration and river closure have become increasingly prominent. The original ecosystems in many river basins were destroyed and the ecosystem service functions were reduced. Water conservation capacity has important service functions such as regulating runoff, purifying water quality, and regulating and storing flood water. As a first-level tributary of the Yellow River, the Qinhe River is an important part of the ecosystem along the river. However, due to the influence of climate change and human activities in recent years, the land use change of the Qinhe River basin is significant, and the inter-annual variation characteristics of water conservation function are gradually complicated. Therefore, exploring the water conservation capacity of Qinhe River basin in the changing environment can provide scientific reference value for ecological protection and high-quality development strategy of the Yellow River basin.SWAT model was constructed, and the land use data set of the Qinhe River basin in 2030 was predicted based on the CA-Markov model to analyze and predict the temporal and spatial changes of water conservation capacity in the Qinhe River basin. Combined with CMIP6 meteorological data, the hydrological factors of the river basin simulated by the SWAT model were obtained according to the principle of water balance. The temporal and spatial changes in water conservation in the past and future years were calculated. In addition, by calculating the ratio of water conservation and precipitation, the index of water conservation rate was introduced to further quantify the water conservation capacity of the basin for storing precipitation and supplying water.The results show that the average annual water conservation is 49 mm and the average annual water conservation rate is 8% in the Qinhe River basin. From 2010 to 2016, water conservation showed a trend of fluctuation and increase, and the water conservation is consistent with the inter-annual variation trend of precipitation. The spatial distribution characteristics of water conservation and water conservation rate in 2010, 2015, and 2025 are similar, showing a trend of increasing from upstream to downstream and decreasing from west to east. However, the spatial distribution characteristics of water conservation and water conservation rate in 2030 are different from other years, and the overall trend is decreasing from the upstream to the downstream, and the water conservation and water conservation rate are negative in the downstream multi-section basins.The analysis showed that the spatial distribution of water conservation rate and water conservation in the basin has a good consistency, and there are negative values in the sub-basins, indicating that the water conservation capacity of the basin is low, the ecological environment is damaged to a high degree, and the ecological water consumption in the river is insufficient, which is in line with the actual situation that the relevant river reaches were cut off.