Impacts of Increased Temperature on the Hydrological Responses from a Multi-scale Perspective across the Yellow River Basin, China

Global warming has brought human society and regional water security tremendous risks. Most of the existed studies about the response of the runoff to temperature change focused on the average temperature and are limited to annual scale. However, from physics mechanism, the daily extreme temperature is also bring a certain impact to the runoff volume and even more important than the average temperature. Accordingly, this study assessing the impacts of temperature variations on streamflow from a multi-scale perspective of the Yellow River basin(YRB) was done using the Variable Infiltration Capacity (VIC) model based on thirty different maximum or minimum temperature increase scenarios (i.e., rising 0.1 °C per step to 3 °C). The results indicated that: (1) The sensitivity of streamflow to maximum temperature rising was more significant than that to the minimum temperature rising. As for the YRB, streamflow changes in downstream were more sensitive to temperature rising than those of area in upstream. Hence, water resource manager should pay more attention to the change of the maximum temperature and the management of water resources in the downstream areas under the background of climate change; (2) The relationship of streamflow with maximum and minimum temperature are showed an upwards parabolic response function, and the streamflow response function displayed different patterns varied with the type of temperature in different stations across the YRB; (3) From the results of seasonal variation of streamflow and the monthly duration curve, although the increase of minimum and maximum temperature has various effects on the seasonal and monthly streamflow, the actions of rising of maximum temperature and rising of minimum temperature are similarly for causing the proportion of high flow and flood season streamflow increases. Overall, the results from this study, in a certain extent can provide beneficial reference to basin-scale water resource management and regional water security.