分析潜在蒸发、径流的时空变化对准确认识气候敏感区实际蒸发和水量平衡变化规律具有重要意义,但受全球气候年际、季节变化等影响,流域层面潜在蒸发、径流难以预测与评估。以气候敏感区黄河源区为研究对象,采用综合差分样本方法(CDSST)划分流域干湿状态为丰水年、枯水年和混合年,并构建了各状态下月尺度abcd水文模型,探究了4种潜在蒸发算法(Haregreaves、Makkink、Penman-Monteith和Jensen-Haise)不确定性对流域潜在蒸发、径流预测不确定性的影响;利用不均匀系数、集中度和相对变化幅度等水文指标,揭示了4种不同潜在蒸发算法对流域水资源预测的影响。结果表明:较1990年之前,流域呈干旱状态的年份增多(由4 a增至10 a),且丰水、枯水和混合年对应的年份个数占比分别为25.86%、24.14%和50%;同时,潜在蒸发算法不确定性改变了流域蒸发量和径流量的时空分布特征。研究结果对于科学掌握变环境下流域水文过程动态变化、区域水资源管理和生态恢复具有重要的参考价值。

Analyzing the spatiotemporal variations of potential evaporation and runoff is crucial for accurately understanding the actual evaporation and water balance changes in climate-sensitive areas. However, due to the inter-annual and seasonal variations of the global climate, predicting and evaluating potential evaporation and runoff at the watershed scale are challenging. In this study, we selected the source area of the Yellow River, a climate-sensitive region, as the research target. We utilized the Comprehensive Differential Sample Method (CDSST) to classify the dry and wet states of the watershed into wet years, dry years, and mixed years. Then, we constructed monthly-scale abcd hydrological models for each state. We also investigated how the uncertainty in four potential evaporation algorithms (Haregreaves, Makkink, Penman-Monteith, and Jensen-Haise) affects the prediction uncertainty of potential evaporation and runoff in the watershed. Subsequently, by employing hydrological indicators such as the unevenness coefficient, concentration degree, and relative variation range, we revealed the influence of these four different potential evaporation algorithms on watershed water resource prediction. Results show that, compared with the period before 1990, the number of years when the watershed was in a dry state increased (from 4 years to 10 years). The corresponding proportions of wet years, dry years, and mixed years were 25.86%, 24.14%, and 50%, respectively. Meanwhile, the uncertainty of potential evaporation algorithms alters the spatiotemporal distribution characteristics of watershed evaporation and runoff. These findings are essential for scientifically grasping the dynamic changes of watershed hydrological processes under changing environments, as well as for regional water resource management and ecological restoration.