Yunnan geographical environment

There are seven climate types in Yunnan province, including north tropical zone, south subtropical zone, middle subtropical zone, north subtropical zone, warm temperate zone, middle temperate zone and plateau climate zone. The climate in Yunnan is characterized by low latitude climate, monsoon climate and mountain plain climate. Its main performance is:

Regional differences and vertical changes of climate

The latitude of Yunnan is related to altitude. From the latitude point of view, its location is only equivalent to the geographical latitude from Leizhou Peninsula to Fujian, Jiangxi, Hunan and Guizhou. However, due to the high terrain in the north and low terrain in the south, the height difference between north and south reaches 6663.6m, which greatly aggravates the temperature difference caused by latitude factors in the whole province. This combination of high latitude and high altitude, low latitude and low altitude is consistent, that is, the increase of latitude in the horizontal direction coincides with the increase of altitude in the vertical direction. Except Jinsha River Valley and Yuanjiang River Valley, the annual average temperature rises from north to south, with an average temperature of about 5 ~ 24℃ and a temperature difference of about 19℃.

Due to the influence of topography and different weather systems, the zonal distribution law of temperature in the whole province often has special circumstances, and the phenomenon of "hot in the north and cool in the south" appears. Especially in the vertical distribution, due to the mountainous territory, the river bed is constantly eroded, resulting in high mountains and deep valleys. From the valley to the top of the mountain, the climate types are different due to the height rise. Generally speaking, the temperature will drop by about 0.6℃ every time the plateau rises 100 meters. ..

The annual temperature difference is small and the daily temperature difference is large.

Because it is located in the low latitude plateau, the air is dry and thin, and the amount and heat of sunlight obtained in various places not only increase or decrease with the change of solar altitude angle, but also are affected by clouds and rain. The average temperature of the hottest day in summer is about19 ~ 22℃; In winter, the average temperature in Leng Yue is above 6 ~ 8℃. The annual temperature difference is generally 10 ~ 15℃, and the temperature is low in rainy days. The daily temperature change is cool in the morning and hot in the afternoon, especially in winter and spring, and the daily temperature difference can reach 12 ~ 20℃.

The precipitation is sufficient, wet and clear, and unevenly distributed.

The annual precipitation in most parts of the province is 1 100mm, and it can reach 1600 mm in some parts of the south. However, due to the control and influence of different atmospheric circulation in winter and summer, the distribution of precipitation in seasons and regions is extremely uneven. In winter, it is located on the west side of Kunming quasi-static front, controlled by a single heating mass, and the precipitation is scarce. Summer is affected by the southwest monsoon, which is humid and sultry with abundant precipitation. The maximum precipitation is six to eight months, accounting for about 60% of the annual precipitation. 10-April is a dry season, and the precipitation only accounts for1/kloc-0 ~ 20% of the whole year. Yunnan has a long frost-free period. The southern border is frost-free all year round; The frost-free period of Wenshan, Mengzi, Simao, Lincang and Dehong in the south is 300 ~ 330 days. About 250 days in central Kunming, Yuxi and Chuxiong; The colder Zhaotong and Diqing reached 2 10 ~ 220 days. Yunnan illumination is 90 ~ 150 kcal per square centimeter every year. Dianchi Lake, located in the south of Kunming, is known as the "Pearl of the Plateau" and is the largest lake in southwest China and the sixth largest freshwater lake in China. The lake area is 3 1 1.388km2, the drainage area is 2920k㎡, the average water depth is 5. 12m, the deepest part is1.3m, and the water storage capacity is155438+0 billion m3. The altitude is 1887m, and the coastline is about 200km long.

Erhai Lake is the second largest plateau lake in Yunnan Province, located in the north of Dali City, with a lake surface area of 252.91km2, a drainage area of 2565k㎡ km2, an average water depth of10.8m, a maximum water depth of 210.5m, an elevation of1966m and a water storage capacity of 28.

Fuxian Lake is the second largest deep-water lake in China, with the largest storage capacity in Yunnan Province. It is located at the junction of Chengjiang County, Jiangchuan County and Huaning County in Yuxi City. Lake elevation 1722.5m, area 216.6km2, watershed area 674.69k㎡, maximum water depth 158.9m, average water depth 92.5m, storage capacity 1893 billion cubic meters.

Chenghai is a deep-water lake in the inland closed plateau with no outflow. Located in the southwest of Yongsheng County, the basin area is 3 18.3km㎡, the lake area is 77.2 km ㎡, the average water depth is 25.9m, the maximum water depth is 36.7m, the storage capacity198.7 million m3, and the coastline length is 45. 1km.

Lugu Lake, located at the junction of northwest Yunnan Province and southwest Sichuan Province, is the third largest deep-water lake in China. The lake area is 508,000 ㎡, including 303,000 ㎡ in Yunnan.

Qilu Lake is a closed plateau lake with an area of 35.9 square kilometers and a drainage area of 354.2 square kilometers. The maximum water depth is 6.8 meters, the average water depth is 4 meters, and the water storage capacity is 65.438+0.7 billion cubic meters.

Xingyun Lake is the upstream lake of Fuxian Lake, which is connected with Fuxian Lake by a 2.2km river. The lake area is 34.7 square kilometers, the basin area is 386 square kilometers, the average water depth is 5.9 1 m, the maximum water depth is 9.5 meters, and the water storage capacity is 65438+84 million cubic meters.

Yangzonghai covers an area of 3 1.9 square kilometers, with an average water depth of 20 meters, a maximum water depth of 29.7 meters, a drainage area of 192 square kilometers, a storage capacity of 604 million cubic meters, and an average water resource of 35 million cubic meters for many years.

Yilong Lake is located in the southeast of Shiping County, with a lake surface area of 92k㎡ ㎡, a drainage area of 360.4k㎡ ㎡, an average water depth of about 5m, a maximum water depth of 6.55m, and a water storage capacity of 1. 1.45 billion. The Yilong Lake Basin mainly includes five towns in Shiping County.

The nine plateau lakes in Yunnan Province are distributed in central Yunnan, southern Yunnan, western Yunnan and northwestern Yunnan, belonging to Kunming, Yuxi, Dali, Lijiang and Honghe. Dianchi Lake, Chenghai Lake and Lugu Lake belong to the Yangtze River system, Fuxian Lake, Qilu Lake, Yilong Lake, Xingyun Lake and Yangzonghai Lake belong to the Pearl River system, and Erhai Lake belongs to the Lancang River system.

Water system: There are more than 600 rivers in Yunnan Province, of which 180 is relatively large, mostly in the upper reaches of rivers entering the sea. Relatively gentle mountainous areas only account for 10% of the total area, and a large area of land has different heights, ups and downs, and a certain range is a gentle plateau. In the longitudinal valley area of western Yunnan, Gaoligong Mountain is the top of the Irrawaddy River and Nujiang River watershed, with snow all year round, forming a strange and magnificent mountain glacier landform. Tiger Leaping Gorge in Jinsha River is one of the world-famous canyons, with a relative height difference of more than 3,000 meters from the mountains on both sides. The straight-line distance from the west swinging iron cable of Lancang River to the top of Kage peak of Meili Snow Mountain is about 12km, and the height difference actually reaches 4,760m m. In the narrow range of 10km, it presents a peculiar landscape of subtropical dry-hot valley and alpine ice and snow world, and the natural scenery is equivalent to the latitude from Guangdong to Heilongjiang.

The whole province is divided into three steps, the first step is in Deqin and Shangri-La counties in northwest Yunnan, the second step is in the central Yunnan Plateau, and the third step is in the south, southeast and southwest, with an average drop of 6 meters per kilometer. Basins and plateaus are commonly known as "bazi" in southwest China.

Geology Museum

Yunnan is also a big geological museum. A large number of sauropod dinosaur fossils were unearthed in the early Jurassic strata in Lufeng County, and they were well preserved. Now this county has built a dinosaur museum for tourists to visit. In addition, Maotianshan Mountain in Chengjiang County is a "star" in geological circles, because a large number of well-preserved Cambrian multicellular fossils have been unearthed here, which strongly proves the existence of the "Cambrian Big Bang". Dongchuan District of Kunming is also a famous "Debris Flow Museum" in China. In the early days, due to the large-scale unscientific mining of copper mines and the influence of climate and topography, large-scale mudslides frequently occurred, and the phenomenon of mudslides was typical.

dam

There are many fault basins in the rolling plateaus and mountains of Yunnan Province. These basins in Yunnan are also called "bazi". There are 445 dams with an area exceeding 1000㎡, 49 dams with an area exceeding1000 ㎡, and the largest dam in Yunnan is in luliang county, with an area of 77 1.99 km2 ... The top dams in Yunnan are Kunming Dam (. hot spring

Anning hot spring and Tengchong Hot Springs

Rock cave

Jianshui Yanzi Cave, Luxi Alu Ancient Cave, Jiuxiang Cave, Maitreya Bailong Cave, Tonghai Lishan Xianren Cave and Eryuan Qingyuan Cave.

volcano

Tengchong volcano