Abstract:
The subject of changing or fluctuating climate is one of the central issues facing the atmospheric
sciences community. The most profound effect of such climatic changes may be major
alterations in regional hydrologic cycles and changes in regional water availability. Within a
context of increasing water scarcity, climate change threatens to exacerbate the current supply
demand imbalance. In this study, the impact of climate change on water availability and the
reliability of the resources to sufficiently satisfy the increasing demand under changing climate
on Finchaa Sub-basin have been modeled and evaluated using the integrated hydrological/water
management model, known as WEAP.
WEAP has been utilized to simulate future water available in the study area using the runoff
generated by the hydrological HBV model as an input. The performances of the models were
assessed through calibration and validation and resulted R
2
value which is greater than 0.8 for all
the three sub-catchments. The predicted future climate variables showed an increasing trend for
both maximum and minimum temperature. However, for the case of precipitation it doesn't
manifest a systematic increasing or decreasing trend in the next century. The results showed that
the total water availability in the study area is expected to decrease by 11.88% (1 , 670.57 Mm
3)
in the next thirteen years. Relative to the base scenario, the simulated future inflow to Finchaa
and Neshe have shown an average slight increment at the end of 2025 and a small decrease at the
end of 2040. But, the simulated future inflow volume to Amerti reservoir has shown that there is
likely a small and considerable decrease at the end of 2025 and 2040 respectively. Considering
the future maximum expansion in the study area, all future and existing demand sites in the study
area are fully satisfied with 100% demand site coverage and 98.89% demand site reliability
under changing climate.
Finally it is concluded that, even though the demand in the sub-basin is increasing steadily, the
study confirmed that the available water resources is enough to satisfy the increasing demand
under changing climate.
