Thai Buddhist monks navigate a small boat Sunday along flooded streets in Bangkok, Thailand. Authorities ordered a spate of new evacuations in the sprawling capital.

BANGKOK — Floodwaters from Thailand’s flood-ravaged central heartland pushed farther into Bangkok today, as residents of long-submerged provinces north of the capital started to rebuild their lives.

The water slowly advancing through Bangkok’s northern and western neighborhoods is threatening the city’s subway system, two key industrial estates and the emergency headquarters set up to deal with the flooding that has claimed more than 500 lives nationwide.

Evacuations have been ordered in 12 of Bangkok’s 50 districts. The evacuations, which also affect parts of several other districts, are not mandatory, and many people are staying to protect homes and businesses.

The flooding began in late July and some provinces to the north of Bangkok have been inundated for more than a month. The waters have started to recede in recent days, revealing the massive cleanup effort that lies ahead.