Floods have been a recurring natural disaster in Sindh, especially in the 21st century. The province is known for its hot and arid climate, however, in recent years, it has been experiencing a shift in its weather patterns, with more frequent and intense drought and rainfall events.

This shift is believed to be a result of climate change, which is causing global temperatures to rise and altering weather patterns worldwide. Despite contributing less than one per cent of the world’s greenhouse gas emissions, Pakistan is one of the most severely impacted countries by extreme weather events resulting from climate change.

Sindh is the only province in Pakistan that has frequently faced all major types of floods, i.e., river, flash, urban, and coastal floods, during the last 25 years. The frequency of floods has been increasing over time, due to which Sindh suffers economic and life losses.

The Cyclone ARB 02 of 1999 was a devastating natural disaster that struck the coastal regions of Sindh and killed hundreds of people, with an economic loss of millions of dollars. Onil in 2004, Yemyin in 2007, and Phyan in 2009 were some of the other major cyclones that flooded the coastal belt of Sindh and resulted in severe human and economic loss in the country.

Sindh is the only province that has frequently faced all major types of floods — river, flash, urban, and coastal — during the last 25 years

Sea level rise, land subsidence, coastal erosion, land degradation, and seawater intrusion are major natural and anthropogenic challenges to the deltaic region of Sindh.

Pakistan is highly vulnerable to climate change impacts. The Global Climate Risk Index 2021 ranked Pakistan as one of the most vulnerable countries in the world to climate change and extreme weather events, despite being one of the lowest carbon emitters in the world.

The initial years of the 21st century were dry for Sindh, but later years were wet, during which the province faced the fury of the 2010, 2011, 2020, and 2022 floods. Flood 2010 was a river flood, 2011 was a rain flood, 2020 was an urban flood, and 2022 was a rain and flash flood.

In 2010, heavy rainfall lashed northern Pakistan, resulting in high flood conditions in the Indus River. The river flow condition was further aggravated when ungauged runoff from Koh-e-Sulman joined the river flow.

The supper flood condition with 1.15 million cusecs of flow resulted in breaches in river levees at two places, i.e., Tori in upper Sindh and Kot Almo in lower Sindh. It flooded about 1.04m hectares of agricultural land, resulting in heavy loss of lives, property, and infrastructure.

Above-normal rainfall occurred in many districts of lower Sindh, including Umerkot, Mirpurkhas, Sanghar, and Badin, during monsoon 2011. It inundated vast areas of these districts resulting in heavy loss of crops, property, and life. Many areas were underwater for more than four months pushing many below the poverty line. This was the first time that sailing boats were witnessed in Mithi town, a town in the middle of the Thar desert.

In 2020, Karachi suffered the worst urban flooding of almost a century. The floods were caused by record monsoon rains, which were inadequately drained by poorly maintained drainage systems in the city. The resulting floods caused deaths and destroyed infrastructure and properties in the city.

Last year, Sindh faced one of the worst floods in its history. The flood was caused by unprecedented rainfall caused by climate change. The flood impacted millions of people, displacing thousands of families and causing extensive damage to homes, infrastructure, and crops.

The province received unprecedented rainfall; up to 1,763 mm was recorded at Padidan meteorological station. The maximum monsoon rainfall was recorded in the central districts of Sindh, ie, Naushehro Feroz, Larkana, and Khairpur districts. This reflects the monsoon rainfall pattern shift from lower Sindh to central and upper Sindh.

The monsoon rainfall volume in Sindh was estimated as 79m acre-feet (MAF). In addition, about 8 MAF runoffs made their way to Sindh and inundated vast areas of Sindh. It is believed that the flood of 2022 was the worse of all floods Sindh has ever witnessed.

Pakistan has been taking steps to address climate change, including adopting the Paris Agreement in 2016. However, more must be done to reduce greenhouse gas emissions and mitigate climate change impacts.

The government should invest in renewable energy and promote sustainable development practices to reduce the country’s reliance on fossil fuels. In addition to addressing climate change, other measures should also be taken to prevent floods in Sindh.

The government should invest in strengthening infrastructure in flood-prone areas, such as check/small dams, river levees, drainage networks, and the revival of natural waterways (dhoras).

It is also important to develop early warning systems to alert communities to impending floods and to ensure that emergency response plans are in place to assist affected communities, especially in Katacha, Kachho, and Coastal areas.

Deforestation is a major cause of flooding in Sindh. Therefore, reforestation (mangrove and inland) efforts should be undertaken to help absorb excess water and reduce the risk of flooding.

The Johi branch canal is a major obstruction in the natural flood flow to Manchar lake, resulting in the inundation of Mehar and Khairpur Nathan Shah towns/talukas. Hence, providing underpasses to the Johi branch canal between Main Nara Valley Drain and Flood Protective bund will reduce the risk of flooding in those towns.

In conclusion, mitigating the impact of floods in Sindh requires a multi-faceted approach that includes investing in infrastructure, improving early warning systems, and raising public awareness. The government and communities must work together to implement these measures and ensure Sindh is better prepared for future floods under changing climate change scenario.

The writer is the dean of the Sindh Agriculture University Tandojam

Published in Dawn, The Business and Finance Weekly, April 3rd, 2023