• Authors of Nature study say flood risks can be mitigated by restoring natural floodplains, improving drainage, moving population away from riverbanks
• Extreme rainfall will become ‘more common and stronger’ by end of the century
ISLAMABAD: Calling the 2022 floods “a forewarning of elevated future flood risks”, a study published in a leading scientific journal warns that Pakistan is likely to experience more frequent and severe floods due to extreme rainfall events and human-induced development encroaching on floodplains.
Published in Nature, the article comprehensively evaluates the complex interplay of pluvial (direct rainfall) and fluvial (riverine) conditions, upstream snow cover dynamics, and anthropogenic changes in the natural landscape that contributed to the unprecedented 2022 flooding.
The study says the Indus Plain in Pakistan experienced 19 flood disasters between 1950 and 2012, affecting an area of 599,459km², causing 11,239 deaths, and resulting in economic damages exceeding $39 billion.
“A significant proportion of these flood events were predominantly attributed to monsoon rainfall, with around 10 out of 20 occurrences taking place after the 2000s,” it added.
According to the paper, after a multi-year drought, the pre-monsoon rainfall in 2022 was 111 per cent higher than the long-term average of 1951–2021, increasing soil moisture by 30pc in the Indus Basin floodplains.
“Monsoon rains were 547pc above average, with record-breaking cumulative weekly rainfall in July (200mm) on already saturated soils. Upstream drainage catchments (e.g., Chenab, Jhelum, and Ravi) received 33pc and 41pc more rain in pre-monsoon and monsoon periods, respectively,” it said, adding that August 2022’s streamflow at Sukkur Barrage, just upstream of the floodplains in Sindh, was 170pc larger than the historical average, due to the compounding effects of rain-on-snow and warmer temperatures accelerating snowmelt.
It said the 2022 flood was triggered by pre-monsoon rainfall followed by an intensified monsoon system, adding that during the monsoon season (July-Sep), rainfall in Sindh and Balochistan surged to “between 600 and 1800mm, far exceeding historical average”.
Anthropogenic changes
According to the study, riverine flooding was amplified by anthropogenic changes, extreme streamflow, and antecedent soil moisture conditions.
“The river water level during the 2022 flood surpassed the levels recorded during the historical catastrophic floods of 2010 and 2015 by 2.4m and 2.79m in Aug. For example, Jun 2022 flows at Sukkur Barrage were 32pc lower than the long-term average (1994–2021), while subsequent months saw increases of 26pc, 105pc, and 170pc, respectively.”
The study revealed human activities were land use adjacent to riverine ecosystems, characterised by intensive agricultural practices and high population density along riverbanks.
For instance, Larkana has consistently expanded toward the riverbanks, with cropland extended from about 37,000km² to 47,500km² between 2001 and 2022.
Another factor that contributed to these floods was the accelerated upstream snowmelt and rain-on-snow events.
‘Adding fuel to fire’
According to the authors of the study, Dr Ali Mirchi and Dr Arfan Arshad, flooding risks in Pakistan could “increase dramatically” under a high-emission scenario, with intense rainfall events, especially 5-day extreme rainfall events in southern Pakistan projected to become “more common and stronger by the end of the century up to 58pc”.
“For example, the frequency of rainfall totals of more than 400mm over five days in this region would increase. At the same time, single-day rainfall extremes (RX1day) could rise by 44pc, pushing already vulnerable regions beyond their coping capacity,” they told Dawn via email.
They said Pakistan could focus on adaptation to mitigate these risks, such as restoring natural floodplains, improving drainage, and shifting development away from riverbanks.
“Pakistan cannot solve global warming alone, but local emission reductions combined with smarter land planning can reduce damage and save lives,” they said.
“To reduce the rainfall-induced direct flooding from urban runoff, we have to fix and upgrade drainage systems in both cities and rural areas to reduce flooding. These are practical, actions that can be done quickly and can go a long way in preventing the kind of widespread damage we saw during the 2022 floods,” the authors said, while stressing the need to improve early warning systems.
Published in Dawn, July 15th, 2025