BRISBANE, Australia — Military aircraft dropped supplies to towns cut off by floods in northeastern Australia as the prime minister promised new assistance today to the 200,000 people affected by waters covering an area larger than France and Germany combined.

Residents were stocking up on food or evacuating their homes as rising rivers inundated or isolated 22 towns in the state of Queensland.

Prime Minister Julia Gillard toured an evacuation center in the flood-stricken town of Bundaberg today and announced that families whose homes had been flooded or damaged would be eligible for disaster relief payments A day earlier, she pledged $1 million in federal aid.

Officials said half of Queensland’s 715,305 square miles is affected by the flooding, which began last week after days of rain caused rivers to overflow.

While the rain has stopped, the rivers are still surging to new heights and overflowing into low-lying towns as the water makes its way toward the sea.

The muddy water inundating thousands of homes and businesses has led to a shortage of drinking water and raised fears of mosquito-borne disease.

The Department of Community Safety said supplies of food and bedding were delivered by road and by military aircraft.

Northeastern Australia often sees heavy rains and flooding during the Southern Hemisphere summer, but the scope of the damage from the recent downpours is unusual.

The entire population of two towns has already been forced to evacuate as water swamped their communities, cutting off roads and devastating crops.

The next city in the water’s path is Rockhampton. Roads and railway lines were expected to be cut off by Saturday, and the city’s airport planned to shut down over the weekend.