Geographical environment of Jing 'an District

The ancient territory is located in the Hudu area of Wusongkou (now Suzhou River). According to old books, Wusong River was 20 Li wide in Tang Dynasty and 9 Li wide in Song Dynasty. After that, it gradually silted up and shrank into 5 Li, 3 Li and 1 Li, and only 10 Zhang Kuan in the Ming and Qing Dynasties. Historically, the lower reaches of Wusong River have been diverted and dredged many times. Wusong River, which flows through the northern part of this area today, is 50 meters wide and 1633 meters long. It is the only existing waterway.

Wusong River was called Songjiang in ancient times, a Songling River and a Lize River. It originates from the Guajingkou of Taihu Lake, flows eastward to Shanghai and enters the Huangpu River, with a total length of 1.25km and a county seat of 20 km, and flows through the towns of Zhaotun, Baihe and Huaxin. Overseas Chinese in the Song Dynasty said, "The ancient Wusong River is deep and wide, comparable to Qianpu." After the Song and Yuan Dynasties, Haikou fell. Although the dynasties devoted themselves to harnessing, they repeatedly dredged, and in the second year of Yongle in Ming Dynasty (1404), Xia Yuanji named Wusong River Liujiahe. Qin Long four years (1570), Governor Hai Rui, Qing Yongzheng five years (1727), deputy capital Chen Shiguan, deepened Wusong River, Huida Yingpu (now East Dayinggang), Zhaotunpu (now West Dayinggang), Panlongpu (now Panlongtang) and Guhuipu (now Tongbo). After liberation, the Dapu River was widened in the 1950s, and algae dikes were excavated in the 1970s to introduce the flood northward into the Yangtze River. Up to now, Wusong River still has a certain displacement. This river is only 40-50 meters wide and can be used for navigation 100 tons of ships. Wusong River is rich in perch and is known as the "hometown of perch". Song Fan Zhongyan, "People come and go on the river, but they love the beauty of habitat". The poem "Look at a boat in the wind and rain" is still recited by people today.

Jing 'an District is located in the center of Shanghai, with small area, large population, dense buildings, scarce green space and busy traffic, which has formed an obvious "heat island" effect throughout the country.

According to the analysis and preliminary study of meteorological data from Shanghai Institute of Meteorological Science 1983 to 1987, Jing 'an District is located in the center of Shanghai's "urban heat island", and the annual average temperature is about 1℃ higher than that in the suburbs. At the same time, it also has the following characteristics: (1) Spring and summer come early, and autumn and winter appear late. The arrival of spring and summer in China is 3 ~ 9 days earlier than that in the suburbs, and 8 ~ 9 days later in autumn and winter. In winter, this area is shorter than the suburbs by 12 days, and it is longer in summer by 17 days. (2) The number of severe cold days is few, with the first ice day appearing late and the last ice day early. The first ice day is about 1 month later than that in the suburbs; In the end, the freezing day was about half a month ahead of schedule. (3) The average number of days with the highest temperature above 30℃ in summer is 67 days, which is 10 more than that in suburbs. The number of days when the temperature is higher than 35℃ is about 10 in the territory and only about 3 days in the suburbs; Extremely hot weather above 37℃ has an average of 2.6 days per year in China, but it rarely appears in the suburbs.