[2] Average rainfall in this area is about 1600 mm, lowest in the whole island of Taiwan, and the rainy season is in summer, thus the plain lacks rain in winter.

These rivers flow over the plain roughly from the eastern mountainous area to the western seacoast, and discharge into the Taiwan Strait.

[5] Han Chinese began to immigrate to the Chianan Plain since the European-ruled era of Taiwan.

After the Koxinga defeated the Dutch to claim Taiwan in 1662, Han people ruled this region, and became the majority later.

In this era, the colonial government launched infrastructure and businesses on the Chianan Plain, such as the Western Line railway, the irrigation system of the Chianan Canal, and sugar production companies which were later combined into the Taiwan Sugar Corporation.

[6] The area can reap three rice harvests annually since the Chianan Canal was established,[7] and also produces peanuts, corn, sweet potatoes and some floricultural plants and vegetables.

Heavy industries situated in this area include oil refining, steel making and shipbuilding.