Abstract
Multi-regression, hydrologic sensitivity and hydrologic model simulations were applied
to quantify the climate change and anthropogenic intervention impacts on the Lower
Zab River basin (LZRB). The Pettitt, precipitation-runoff double cumulative curve (PRDCC)
and Mann-Kendall methods were used for the change points and significant
trend analyses in the annual streamflow. The long-term runoff series from 1979 to 2013
was first divided into two main periods: a baseline (1979-1997) and an anthropogenic
intervention period (1998-2013). The findings show that the mean annual streamflow
changes were consistent using the three methods. In addition, climate variability was
the main driver, which led to streamflow reduction with contributions of 66-97% during
2003-2013, whereas anthropogenic interventions caused reductions of 4-34%.
Moreover, to enhance the multi-model combination concept and explore the simple
average method (SAM), Hydrologiska Byrans Vattenbalansavdelning (HBV), Génie
Rural a Daily 4 parameters (GR4J) and Medbasin models have been successfully
applied.