<p>Driven by climate change and anthropogenic activities, watershed hydrological processes are undergoing significant nonstationary changes, with increasing variability and more frequent extreme events. These changes have triggered cross-regional hydrological concurrence, which remains understudied compared with single-watershed anomaly analyses. To address this gap, daily runoff data from 27 small watersheds in the Yellow River Water Conservation Area are analysed in this study to identify subseasonal and seasonal anomalies, reveal the spatio-temporal patterns of multitype hydrological concurrence, and quantify key drivers using an XGBoost-SHAP explainable model. The results indicate that subseasonal anomalies occur more frequently and exhibit greater spatial heterogeneity, whereas seasonal anomalies are longer lasting, suggesting the presence of both short-term and cumulative hydrological risks. Hydrological concurrence shows clear seasonal prevalence, with higher probabilities at the seasonal scale. From a temporal perspective, the frequency of concurrence increased, particular for pluvial and drought concurrence at the subseasonal scale. From a spatial perspective, concurrence was more common in the eastern part of the study area, occurring most often in the Weihe South Mountain Region. Driver analysis revealed that temperature dominated subseasonal concurrence, whereas vegetation and hydrothermal conditions played a greater role at the seasonal scale. These findings highlight the complex and scale-dependent nature of hydrological concurrence under a combination of climatic and anthropogenic influences.</p>