Huaihua physical geography
Huaihua is known as "the gateway to Guizhou and Yunnan" and "the throat of all Chu", and it is the "bridgehead" leading to the southwest from the eastern and central parts of China, and now it is known as the "west gate" of Hunan. Huaihua is located between Wuling Mountain and Xuefeng Mountain, and Shui Yuan runs through the whole territory from south to north.
Xuefeng Mountain: It starts from Foding Mountain in Yuechengling in the north and passes through Chengbu, Hongjiang, Xupu and Anhua counties and cities in the north, with a total length of more than 200 kilometers. It's curved. The main peak is at an altitude of 1000- 1500m, and the highest peak, Subaoding Mountain, is at an altitude of 1934m in hongjiang city. The west slope of Xuefeng Mountain is gentle and the east slope is steep, which has become the natural dividing line between eastern and western Hunan and the watershed between Zishui and Shui Yuan.
Wuling Mountain: Wuling Mountain belongs to the eastward extension of Wuyunshan branch of Yunnan-Guizhou Plateau. North to east, distributed in northwest Hunan. The altitude is mostly 800- 1200m. Among them, there are more than 200 peaks above 1000 meters above sea level, and the highest peak, Huping Mountain, is 2098.7 meters above sea level. The mountain is tall and majestic. The northern branches of the mountain range include Bamian Mountain, Badagong Mountain, Qinglong Mountain, Dongshan Mountain and Huping Mountain. The northern branch of the mountain range includes Tianxing Mountain, Hongxing Mountain, Chaotian Guanshan Mountain, Zhangjiajie Mountain and Baiyun Mountain. Along the main stream of Lishui River, the south branch extends from Guizhou Province into the province, including La 'er Mountain, Yangfeng Mountain, Tianmen Mountain, Dalongshan Mountain and Liutai Mountain. All the above three mountains disappeared in Dongting Lake Plain.
Huaihua was called "the land of five streams" in ancient times. Five streams in a narrow sense refer to Huaihua City, Hunan Province. Its important tributaries are Youshui, Chenshui, Xu Shui, Wushui and Qushui.
The five streams in a broad sense are the five tributaries in the upper reaches of Yuanshui River, which was first seen in the water mirror note: "There are five streams in Wuling, namely Xiong Xi, Manxi, Youxi, Wuxi and Chenxi". Its scope is centered on Huaihua, including the surrounding areas of Hunan, Guizhou, Chongqing and Hubei, and more than 30 counties and cities. There are 3 1 ethnic minorities in Wuxi, which is an important ethnic minority area in southern China in history.
Yuanjiang: Yuanjiang, also known as Shui Yuan, is the second largest river in Hunan Province. It is divided into two sources, namely Longtou River in the south, Wuyun Mountain in Duyun, Guizhou, and Chong 'an River in the north, which originated from Yuejian Mountain in Majiang County, Guizhou. After the confluence of the two sources, it is called Qingshui River, which flows eastward to Zhijiang County, Hunan Province, where hongjiang city Qiancheng meets Wushui, and then flows through Huitong and Hongjiang. The total length of the main stream is 1033km (568km in Hunan), and the drainage area is 89 163km, including 5 1066km in Hunan, with an average annual runoff of 39.33 billion cubic meters. Huaihua city belongs to the subtropical monsoon climate zone, with four distinct seasons, no severe cold in winter and no heat in summer. Abundant light and heat resources, abundant rainfall and synchronous rain and heat are beneficial to crop growth. However, due to the influence of topography, the regional and vertical differences are obvious, the climate types are diverse, and natural disasters such as droughts and floods occur from time to time. Temperature: the annual average temperature of the whole city is 16.4℃, which is higher in the mountainous basin in the southwest and lower in the hills in the north and south. 65438+ 10 is the coldest month, with an average temperature of 4.7 ~ 5.3℃ and a minimum temperature of around -5℃. It is hottest in July, with an average monthly temperature of 28.5℃ and a maximum temperature of about 39℃. The average annual frost-free period is 287 days.
Sunshine: There is plenty of sunshine in China, and the average annual sunshine hours are 962- 1452 hours, accounting for 28-34% of the available sunshine hours. The annual sunshine hours are mostly in Zhijiang, Xupu and other mountain basins, mostly in 1500 hours, and the annual sunshine hours are at least in Xinhuang, only 1300 hours.
Precipitation: the national average rainfall is about 1600 mm, the average annual rainfall in Xupu, he cheng, Zhong Fang and Hongjiang in the eastern half is 1600 mm, and Mayang, Xinhuang, Zhijiang and Huitong in the western half are less than 1300 mm, with the most frequent rainfall in the northern and southern passages.
Characteristics of four seasons: Due to the advance and retreat of winter and summer monsoon, the weather and climate characteristics of each season in China are formed. Spring is in the zone where warm and humid air flows in the south and dry and cold air flows in the north interweave, with obvious temperature fluctuation, continuous spring rain and low temperature. In summer, controlled and influenced by the subtropical high in the western Pacific, southwest winds blow, with high temperature, large evaporation and hot weather; Autumn is crisp, warm and humid; The invasion of strong cold air in winter often leads to snow and ice weather, but the amount is very small, and it can melt after two or three days of continuous snowfall.