变化环境下黄河上游径流变化及归因探析OA

The upper reaches of the Yellow River(UPYR)serve as the primary source area for the basin's runoff.It is essential to quantify the impacts of climate change and anthropogenic activities on the variation patterns of runoff in this region to enhance effective water resource management and support informed decision-making within the Yellow River Basin.In this study,we developed the SWAT hydrological model for the upper reaches of the Yellow River,calibrating and validating it from the base period of 1964 to 1980.We systematically evaluated the effects of climate change and human activities(including water usage,reservoir regulation and land use)on runoff changes from 1981 to 2020.The findings indicate that:a)The basin is currently undergoing a significant increase in both precipitation and temperature,with pre-cipitation levels rising at a rate of 8.11 mm per decade and a corresponding warming rate of 0.35℃per decade.It is important to note that there is spatial heterogeneity in the intensity of the impacts of climate change.In the source area,the contribution rate of climate factors at the Jimai Station is 94%.In contrast,at the Toudaoguai Station,the contribution rate decreases to 21%.b)The influence of human activities on runoff attenuation exhibits spatial gradient characteristics,with variations ranging from 60%to 80%between Lanzhou and Toudaoguai section.Water abstraction and consumption are identified as the principal contributing factors,accounting for approximately 40%to 45%of this phe-nomenon.The establishment and operation of the reservoir have resulted in a temporal redistribution of runoff,leading to a decrease of 18.11%±6.27%during the flood season and an increase of 12.33%±4.2%during the non-flood season.c)Between 1964 and 2020,the an-nual runoff in the upstream region of the Yellow River experienced a decline of 148 million cubic meters per decade.An analysis of the factors contributing to runoff reveals that precipitation recharge is the primary determinant,accounting for approximately 80%±11.33%.This is fol-lowed by contributions from snow and ice melt,thawing of frozen soil and groundwater recharge.The findings of this study elucidate the non-linear superposition effects of climate change and anthropogenic activities in the upper reaches of the Yellow River,thereby providing theoret-ical support for understanding the variations in upstream runoff in the context of climate change.