The death toll in each of those three disasters was much higher than the 1,500 people killed so far in the floods that first hit Pakistan two weeks ago. But the Pakistani government estimates that over 13 million people have been affected - two million more than the other disasters combined.
The comparison helps frame the scale of the crisis, which has overwhelmed the Pakistani government and has generated widespread anger from flood victims who have complained that aid is not reaching them quickly enough or at all.
''It looks like the number of people affected in this crisis is higher than the Haiti earthquake, the tsunami or the Pakistan earthquake, and if the toll is as high as the one given by the government, it's higher than the three of them combined,'' Maurizio Giuliano, spokesman for the UN Office for the Coordination of Humanitarian Affairs, told The Associated Press.
The UN has provided a lower number of people who have been affected in Pakistan, about 6 million, but Giuliano said his organization does not dispute the government's figure. The UN number does not include the southern province of Sindh, which has been hit by floods in recent days, and the two sides have slightly different definitions of what it means to be affected.
The total number of people affected in the three other large disasters that have hit in recent years is about 11 million - 5 million in the tsunami and 3 million in each of the earthquakes - said Giuliano.
Many of the people affected by the floods, which were caused by extremely heavy monsoon rains, were located in Pakistan's northwestern province of Khyber Pakhtunkhwa.
Rescue workers have been unable to reach up to 600,000 people marooned in the province's Swat Valley, where many residents were still trying to recover from an intense battle between the army and the Taliban last spring, said Giuliano. Bad weather has prevented helicopters from flying to the area, which is inaccessible by ground, he said.
''All these people are in very serious need of assistance, and we are highly concerned about their situation,'' said Giuliano.
Hundreds of thousands of people have also had to flee rising floodwaters in recent days in the central and southern provinces of Punjab and Sindh as heavy rains have continued to pound parts of the country.
One affected resident, Manzoor Ahmed, said Monday that although he managed to escape floods that submerged villages and destroyed homes in Sindh, the total lack of government help meant dying may have been a better alternative.
''It would have been better if we had died in the floods as our current miserable life is much more painful,'' said Ahmed, who fled with his family from the town of Shikarpur and spent the night shivering in the rain that has continued to lash the country.
''It is very painful to see our people living without food and shelter,'' he said.
Thousands of people in the neighboring districts of Shikarpur and Sukkur camped out on roads, bridges and railway tracks - any dry ground they could find - often with nothing more than the clothes on their backs and perhaps a plastic sheet to keep off the rain.
''I have no utensils. I have no food for my children. I have no money,'' said Hora Mai, 40, sitting on a rain-soaked road in Sukkur along with hundreds of other people. ''We were able to escape the floodwaters, but hunger may kill us.''
A senior government official in Sukkur, Inamullah Dhareejo, said authorities were working to set up relief camps in the district and deliver food to flood victims.
But an Associated Press reporter who traveled widely through the worst-hit areas in Sindh over the past three days saw no sign of relief camps or government assistance.
The US and other international partners have stepped in to support the government by donating tens of millions of dollars and providing relief supplies and assistance.
But the UN special envoy for the disaster, Jean-Maurice Ripert, said Sunday that Pakistan will need billions of dollars more from international donors to recover from the floods, a daunting prospect at a time when the financial crisis has shrunk aid budgets in many countries.
