PROGRESS IN GEOGRAPHY ›› 2017, Vol. 36 ›› Issue (7): 864-872.doi: 10.18306/dlkxjz.2017.07.008

• Orginal Article • Previous Articles     Next Articles

Comparative study on two automatic baseflow separation methods in the arid and semi-arid regions

Rui LI1,2,3(), Shifeng ZHANG1,2,*()   

  1. 1. Institute of Geographic Science and Natural Resources Research, CAS, Beijing 100101, China
    2. Key Laboratory of Water Cycle and Related Land Surface Processes, CAS, Beijing 100101, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2017-07-31 Published:2017-07-31
  • Contact: Shifeng ZHANG E-mail:lirui6553@163.com;zhangsf@igsnrr.ac.cn
  • Supported by:
    Key Research Program of the Chinese Academy of Sciences, No.KFZD-SW-301;National Natural Science Foundation of China, No.41171032

Abstract:

Baseflow is a crucial component of streamflow. In the arid and semi-arid region, baseflow plays an important role in maintaining the stability and sustainability of the river flow and determining the ecological water requirement. Therefore, the results of baseflow separation are of great importance. In our research, a typical drainage basin located in the upstream of the Yellow River region was taken as the study area. Considering runoff in several typical years, we used smoothed minima and determined the parameters of digital filtering. Then we used digital filtering for baseflow separation using the data from 1980-2014 and analyzed the trend of baseflow. The results show that digital filtering performed better in the arid and semi-arid region and the results gained from smoothed minima indicate lower baseflow values. In areas where the parameters are difficult to determine, baseflow estimation should take advantage of both methods. The average BFI of the study area from 1980 to 2014 was 0.69, which was greater than the national average (0.26), BFI of the rivers in northwestern China (0.57), and BFI of the Yellow River region (0.43). Trend analysis shows that the increase of annual flow, baseflow, and BFI was 0.086 (m3/s)/10a, 0.169 (m3/s)/10a, and 0.038/10a. MK trend test results show that the growth of annual flow was not obvious because it did not pass the significance test of 90%; baseflow and BFI showed significant positive trends for they had passed the significance test of 97.5% and 99% respectively.

Key words: arid and semi-arid regions, automatic baseflow separation, smoothed minima, digital filtering, baseflow index