Most of downtown Osaka lies on the Osaka Plain. Osaka Plain is an alluvial plain with flat terrain. About 8,000 to 7,000 years ago, Osaka Plain was once located under the sea, and it was called Hanoi Bay because of the high water level caused by rope transgression. By the middle of Wensheng, as the sand mouth on the north side of Shangmachi platform gradually extended northward, Hanoi Bay evolved into a lagoon, which was called Hanoi Lake. After entering the ancient grave era, due to the continuous accumulation of soil and sand in rivers and the artificial development of lakes as cultivated land, Lake Hanoi has almost disappeared and turned into Osaka Plain.

In order to expand the land area, Osaka has reclaimed land for many times. The large-scale reclamation project in Osaka began with the development of Xintian in the17th century. A quarter of downtown Osaka comes from reclamation. The islands along Osaka, such as Mengzhou, Wuzhou and Suizhou, are also artificial islands formed by land reclamation.

Osaka is located in the north temperate zone, with four distinct seasons and warm all year round. It belongs to Seto inland sea climate, which is similar to the coastal areas in southern China. There is plenty of precipitation all year round, it is a bit sultry in summer, and it seldom snows in winter. The annual average temperature is about 16℃, and the average precipitation is about 1306 mm. ..

In spring (March-May), the lowest temperature is 3℃- 15℃, and the highest temperature is 15℃-25℃. Sakura viewing places in Osaka: Mint Bureau, Wanbo Memorial Park, Maruchi Garden in the west of Osaka, Sakura Palace Park in Maojian and Wushan Park.

In summer (June-August), the lowest temperature 17℃ ~ 25℃ and the highest temperature 15℃ ~ 32℃. With the arrival of the rainy season in early summer, the temperature rises gradually.

In autumn (September ~165438+1October), the lowest temperature is 8℃ ~ 14℃, and the highest temperature is 12℃ ~ 20℃.

In winter (65438+February ~ February), the lowest temperature is 2℃ ~ 5℃, and the highest temperature is 8℃ ~ 12℃. Suitable for enjoying the winter scenery and skating and skiing. There are vertical and horizontal rivers in Osaka, and the water area accounts for more than 65,438+0/65,438+00 of the urban area. More than 0/400 unique bridges on the river/KLOC-connect the whole urban area, which is known as both the "Water Capital" and the "Osaka 808 Bridge".

Among Osaka's water systems, Dianchuan, which originates from Lake Biwa and flows through the north of Osaka, has the largest amount of water. With the convenience of water transportation, there are many markets in Dianchuan area, which is the main artery supporting Osaka's economy. However, Dianchuan used to be a river with frequent floods. /kloc-the Dianchuan flood in 0/885 made the Meiji government determined to dig a new Dianchuan on the north side of Dianchuan, which made the drainage of Dianchuan smooth and greatly reduced the number of floods. The main rivers in downtown Osaka are hikawa, Tootsukawa, Kizukawa, Anji Chuan and so on.