ABSTRACT
Past (1980–2020) and anticipated (until 2100) alterations in the hydrological cycle, caused by climate change, have significant effects and potential hazards on the water and ecological systems. This chapter uncovers some important findings related to the recent and future changes in the precipitation characteristics in terms of intensity-duration-frequency (IDF) relationships and probable maximum precipitation (PMP). Due to anthropogenic climate change, heavy precipitation intensity has increased since the 1950s; ~700 million people experienced longer dry spells than shorter ones. Between 1970 and 2019, 31% of all economic losses were caused by floods, while 7% of all catastrophe occurrences globally were connected to drought. Direct flood damages are anticipated to increase by a ratio of four to five at 4°C as compared to 1.5°C. Around 4 billion people are anticipated to face physical water shortages if global warming levels are projected at 2°C and 4°C. India is no longer the exception, anticipating a drastic increase (~41–44%) in hourly precipitation intensity under SSP585 such that frequency dominated (three times increase at 99th percentile) over the daily precipitation intensity. Furthermore, 70–80% of the Indian mainland is projected to witness a 20–35% increase in PMP. The advantages of observed water adaptation responses are numerous to combat the aforementioned implications, but methodological difficulties have made it challenging to establish whether adaptation reduces climate risks.
