HU Ke-ke, HE Jian-cun, ZHAO Jian, TA Yi-er, SU Li-tan
Ecological base flow plays a pivotal role in maintaining the health and stability of river ecosystems, especially in inland arid areas that lack sufficient water resources. This study focuses on three representative seasonal inland rivers, namely the Kriya River, Niya River, and Qarqan River, located on the northern slope of the Kunlun Mountains. By analyzing hydrological data from 1978 to 2014, we employed four hydrological methods, including the QP method, Tennant method, the Texas method and others to calculate and determine the ecological base flow values of the three rivers. Furthermore, we investigated their spatial-temporal differentiation characteristics and influencing factors. The results indicate that the Tennant method is more suitable for calculating the ecological base flow in the northern slope of the Kunlun Mountains. In terms of temporal variation, the maximum monthly flow values for all three rivers occurred in July, while the minimum values in January. The interannual maximum flow was observed in near 2010, whereas the minimum value recorded in near 1980,increasing at rates of 1.378 m3/s·(10 a)-1,0.653 m3/s·(10 a)-1,and 3.066 m3/s·(10 a)-1,respectively, for the three rivers. Regarding spatial distribution, the Qarqan River exhibits the highest flow rate in spring, followed by the Kriya River, and then the Niya River. In summer and autumn, the ranking changes to Kriya River,Qarqan River,and Niya River in descending order.Despite evident fluctuations in the same river, the differences in changes between different rivers are not significant (p>0.05). The primary factors influencing the temporal and spatial differences in ecological base flow are temperature, precipitation, and human activities. Among these factors, the Qarqan River Basin demonstrates the strongest correlation between temperature, precipitation, and ecological base flow, with correlation coefficients r=0.876 and r=0.917,respectively.Taking into account the spatial and temporal distribution of ecological base flow and the characteristics of climate change in the basin, we propose comprehensive management and control objectives for each month in a year for the three rivers. The findings can serve as a valuable reference for river ecological restoration, as well as water resources management and allocation on the northern slope of the Kunlun Mountain.
