Hydropower dam and hydrological alteration on the Da river in Son La, Vietnam

The flow regime information from 1961 to 2016 was obtained from the Vietnam Meteorological and Hydrological Administration. The hydrological alteration was quantified by using IHA (Indicators of Hydrologic Alteration). The Kruskal – Wallis test was applied to examine the changes of hydrological regime between pre- and post- dam period. The results showed that 4 groups of IHA had significant change and one group had no significant difference in preand post-dam period.