Geographical environment in jianghai area

Jianghai District is the jurisdiction of Jiangmen City, which has five sub-district offices, namely Waihai, Li Le, Jiangnan, Jiaotou and Jiaobei, with a total area of 1 10.53 square kilometers. Jianghai District is located in the southeast of Jiangmen City, in the center of the municipal district, facing the ancient town of Zhongshan City across the river in the east, Zhou Mu Town in Xinhui District in the south, Huicheng in Xinhui District in the west and Pengjiang District in the north.

Jianghai District, located between 22 2923 22 3623 N and165438 E+03 0345131050, is the hub of the lower reaches of Xijiang River. The land distance is Guangzhou10/km, Hong Kong 265 km and Macau 107 km; The waterway is 0/06 km from Guangzhou/KLOC-,95 nautical miles from Hong Kong and 53 nautical miles from Macau. Land and water transportation is vertical and horizontal, which is very convenient. In 2003, the area was 1 10.53 square kilometers, of which the land area was 102.34 square kilometers, accounting for 93% of the total area; The water area is 7.66 square kilometers, accounting for 7% of the total area. The land-water area ratio is 1: 13.36. In the long geological age, due to the internal and external geological stress, the territory gradually formed a multi-dimensional landform with high in the north and low in the south and inclined from north to south. The white water belt in the west is hilly and terraced, and the southern part is flat and wide delta plain.

1 100 million years ago, in Proterozoic, Jianghai jurisdiction, like most parts of Guangdong, was northeast-southwest. In the trough with frequent ups and downs, by the end of Cambrian in Lower Paleozoic, due to Caledonian orogeny, deep magma invaded the crust and the sedimentary strata in the area locally rose. After a long period of weathering and denudation, hills such as Niu Shan and Jishan, platforms and residual hills of Nandagang were formed. The area south of Jiaotou-Ma Yuan-Waihai Line is a transitional zone between land and sea, belonging to late Pleistocene river alluvial plain, where gravels, gravels, medium coarse sand and silty fine sand with a thickness of about1~ 7m are deposited. In the early Holocene, it was affected by transgression. In the middle of Holocene, the temperature gradually increased, the sea level continued to rise and the sea water deepened. At the beginning of the late Holocene, seawater still affected this area. East Li Shuwei in Lille Town has an 800-meter-long and 3-meter-thick oyster shell dam. There is a marine erosion platform in Nanshan, an offshore area, and there are obvious oyster shells in the plain strata in front of the platform, which fully proves that the territory of Jianghai District used to be the sea. With the alluvial accumulation of the Pearl River, the coastline keeps moving forward and the sea water gradually recedes. In the Song Dynasty, the delta plain was initially formed. Jianghai District is located in the south of the Tropic of Cancer, near the South China Sea. It has a subtropical maritime monsoon climate, with southwest monsoon blowing in summer and northeast monsoon prevailing in winter. The climate is mild throughout the year, with no heat in summer, no severe cold in winter, long summer and short winter, abundant sunshine, abundant rainfall, long frost-free period and evergreen seasons. The daily average temperature is 2 1.8℃ ~ 23.2℃, and the annual rainfall is 1600 ~ 2700 mm.

Spring (mid-February to late April): cold air activity is weakened, warm and humid air flow in the south is enhanced and pushed northward, and the temperature rises obviously. Precipitation increases, with occasional heavy rains and floods. Low temperature, rainy weather and late spring cold often appear in early spring. Tropical cyclones will appear in a few years.

Summer (from the end of April to the end of 10): Southwest monsoon prevails, which is the season with the most abundant rainfall, heat and sunshine throughout the year. Strong convection and lightning weather are frequent and are often affected by tropical cyclones. In midsummer, controlled by subtropical high, the weather is hot. In the year when cold air activity is early and strong, cold dew wind will appear after late September, which is not good for heading and flowering of late rice.

Autumn (from the end of 10 to the middle of 10): affected by the invasion of cold air from the north to the south, the temperature gradually drops, the precipitation decreases, there are many sunny and dry days, the temperature difference between day and night is large, and there are occasional frosts.

Winter (65438+1late October to mid-February): Northeast monsoon prevails. The climate is cold and light rain, and slight cold to severe cold is the coldest time of the year. Due to the frequent southward movement of cold air, disastrous weather such as cold wave, low temperature, rainy weather and frost often occurs. Sunshine hours account for 36% of sunshine hours, and solar radiation accounts for 18% of the whole year.

Typhoons, rainstorms, cold waves and floods occur from time to time, and industrial and agricultural production is affected to some extent.