Tiandeng's geographical environment

Tiandeng County has a subtropical monsoon climate. Because it is mountainous and has a high altitude, the climate is cooler and wetter than that of neighboring counties. In late spring and early autumn, it is mostly affected by southerly airflow, with high temperature, high humidity and heavy rainfall. Winter is affected by the cold wave in the north, with low temperature, low humidity and little rainfall.

The county is located in the south of the Tropic of Cancer, with a large amount of solar radiation. The annual average total solar radiation is 100.6 kcal/cm2, and its geographical distribution is more flat land and less mountainous area. In a year, the lowest value generally appears at about 5.5 kcal/cm2 in 65438+1October, and gradually increases from February to July, reaching the highest value in July, and then gradually decreases. The county meteorological station is surrounded by mountains, and the average sunshine hours are less than 1520 hours, and the maximum is 1965, reaching 1768.9 hours; At least 1960, only 1 138.4 hours. The annual sunshine percentage is about 33.7%. The geographical distribution is similar to solar radiation, with more flat land and less mountains. In a year, it is rainy from June to April, and there is little sunshine. The average sunshine in each month is below 100 hour, especially in February and March, with an average of just over 2 hours per day. From May to June, it increased to an average of more than 4.5 hours per day. From July to September, the sunshine is the most, and the monthly value exceeds 170 hours, nearly 6 hours a day. From June 10 to February 12, it gradually decreased, and in June 12 was only 109 hours. The number of sunshine hours in the sky can meet the growth needs of crops in one year. Tiandeng LAM Raymond Valley is mostly a fault zone with strong water permeability and undeveloped surface water system. There are more than 20 rivers in the county, all of which are formed by large and small springs. In dry season, the flow rate is lower than 1 m3/s, the average flow rate is 1 m3/s ~ 3 m3/s, and it is as high as 100 m3/s in flood season.

The main streams and rivers are:

Taiping River, called Ganrongjiang in ancient times, originated in Jilan Village, Bahe Township, and there is Lan Ruo Reservoir in the territory. It joins the Nabi River, a tributary of 99 Ridges, through Welfare Village and Lejiu Village of Du Xiang Town, and enters Tiandong County after Xianglong, Zhonghe and Pingyao Village, belonging to Youjiang.

Han Donghe, also known as Dahanxi, originated in Hantun Village, Han Dong Village, Du Xiang Town, entered Debao County via Han Dong and returned to Youjiang.

Tiandeng River, also known as Ronghua River and Dukang River, originates from Naiyingshan Nianxiang Reservoir in Lu Xian Village, Du Kang Township, passes through Fuman Reservoir in yongle village, Gansu Ningxiang to Jinna Village, Gansu Province, and joins the tributary from 99 Ridges. After crossing Longsheng Village, Jiangxiang Village in Du Kang Township, Daoxiang Village in Hualong Township and Ronghua Village, it flows into the tributary of Gutao River and enters Tiandeng Town. After crossing Hongling and Shengdian Village in Hualong Township, dive underground, leave Longan County and return to Youjiang. In winter, there is little river water, which flows to the leaky pump at the junction of Li Chuan Village in Tiandeng Town and Hongling Village in Hualong Township, and enters the tiankeng, and the section from Hongling to Shengdian Village dries up.

Jinjie River, called Buyu River in ancient times, originated in Namongtun, Luolong Village, Tuokan Township, passed through Wen Xiu Village, Jiean Village, Jinjie Town, and merged into Dongning River, which originated in Tuanle Village, Jinjie Town. After Longfeng Minyuan Village, enter the underground river, leave Pingguo County and return to Youjiang.

The Nazao River originates from Quanshui and Sanshou Village in Dongping Township, and then flows into Tiandong County to join the dry river and return to Youjiang.

Longming River, called Longjiang in ancient times, originated from Miao Village and Zhongdian Village in Fuxin Township at the eastern foot of Sichengling, and then merged with the tributary of Peiguang Village in Xiang Ying Township at the northern foot of Sichengling. After Longying, Sanbei, Xiaoshan and Longqiao Village, enter Lijiang, daxin county and return to Zuojiang.