Increased glacial melting and associated glacier flooding, landslides, and avalanches could have significant impact on hydropower in some parts of Pakistan, Nepal, Bhutan and Peoples'' Republic of China, an Asian Development Bank (ADB) study says.
This ADB report titled ''Climate Risk and Adaptation in the Electric Power Sector'' argues that "in general, climate change and the modification of rainfall and temperature patterns can affect hydropower output in four major ways: (i) surface water evaporation, (ii) reduced runoff due to drought, (iii) increased runoff due to flooding, and (iv) siltation". Higher precipitation could increase seasonal river flows, but higher evaporation could reduce water storage in the reservoir, the report adds.
Increased variability in weather (intensity of peak flows, changes in seasonal patterns) could increase uncertainty in river flows and the capacity of reservoir storage (eg, days of stored water supply), disrupting expected supply patterns.
The study reveals that in general, a one percent change in precipitation is likely to result in at least a one percent change in power generation. Although changes in power generation are harder to predict for run-of-river systems. Other potential impacts of climate change on hydropower can be wide-ranging and severe.