Environmental change not only quantitatively affects water resources, but also causes non-stationarity in hydrological processes, which challenges the applicability of traditional drought assessment methodologies. Based on data for 1961 to 2013 from two hydrological stations, 62 rain gauge stations, and 24 meteorological stations within the Weihe catchment, this study evaluated the effect of climate change and human activities on runoff reduction using a macro-scale distributed hydrological model along with the Variable Infiltration Capacity (VIC) model. The spatiotemporal characteristics of hydrological drought were analyzed by the Standardized Runoff Index (SRI) which was calculated by multi-parameterization schemes. The robustness of SRI under non-stationarity as well as the impact of environmental change on the hydrological evolution were analyzed. Results showed that the observed significant runoff reduction at the Xianyang and Huaxian hydrological stations in the period of 1991-2013 was mainly due to human activities, which accounted for -66.7% and -71.0% of the total change, respectively. The SRIv
series that were based on the time-variant parameterization scheme, could rationally reproduce the historical hydrological droughts. It was also found that after 1991 human activities mainly resulted in the short-term drought fluctuation and climate change mainly led to the trends of droughts and floods in the Weihe catchment.