Assessment of Streamflow Regime Alterations in Tang River, China

The biodiversity and integrity of river ecosystems are depending on the natural streamflow regime. Therefore, assessing alteration of hydrologic regimes becomes a fundamental step in river ecosystem protection and restoration. In this paper, the Range of Variability Approach (RVA) was used to analyze the alteration hydrologic regimes from 1959 to 2016 in the Tang River, the upstream of Baiyangdian Lake Basin, China. Several results can be drawn: (i ) annual streamflow presented a decreasing trend, and an abrupt change was detected in 1979; (ii ) the significant changed indicators of hydrologic variation in upstream of Baiyangdian Lake Basin were the monthly streamflow in March, April, August, November, time of 3-day and 90-day maximum streamflow, date of maximum streamflow occurrence, rise rate and number of reversals; and (iii ) monthly water should be restored in flood and delivered in non-flood season, and annual extreme streamflow frequency and duration of high and low streamflow also should be regulated to maintain the streamflow regimes in the Tang River Basin, China. The results will help to provide the suitable ecological streamflow and maintain the integrity of river ecosystem in changing environment.