According to the geomorphological reasons, morphological characteristics and lithological combination of the principle of the territory can be divided into three levels:
The first stage is the genetic type, and the dominated formation of the controlled geomorphology is divided into erosive and erosional tectonic landforms, erosive denudation topography and accumulation topography.
The second level is morphological genetic type, which is divided into mountainous, hilly, hillock and plain according to the basic morphological features.
(M), granite (g), limestone (m), sandy shale (s), glutenite (c), red rock (r (m)), ), The fourth-level loose accumulation of landforms.
| Geomorphic types | Surface morphological characteristics | Altitude (m) | Relative elevation (m) | slope | Constituent material |
|---|---|---|---|---|---|
| Mountain | Mountainous ups and downs, linear extension, clear context, strong cutting, bedrock exposed, obvious structural trajectories | ||||
| Zhongshan | >800 | 600 | >75° | Metamorphic rocks and granites | |
| In the low mountains | 500-800 | 400-600 | >30° | Sand shale, sand and gravel | |
| Low mountain | 300-500 | Metamorphic rocks | |||
| Hills | Wavy ups and downs, context is not clear | ||||
| Hill top, mostly rounded, multi-bedrock exposed | <300 | 150-200 | 15°-25° | Red rock, granite, sand shale | |
| Just ground, ups and downs of the slow, cutting is not strong | <100 | 10-60 | <15° | Bedrock, Quaternary material | |
| Bedrock, Quaternary material... | <50 | <5° | Quaternary material | ||
Mountain is the neotectonic movement period, the relative rise of the crustal zone. Long-term erosion and erosion. Geological structure in the geomorphology of a certain performance, the main ridge line and gully extension direction, roughly consistent with the construction line. The mountains are mostly distributed in the northeast, east and southeast of the periphery. Mountain area of 2240.86 square kilometers, accounting for 15% of the total area, according to morphological characteristics can be divided into Zhongshan, in the low mountain, low mountain three sub-categories.
Zhongshan
For example: Linxiang City, Yao Gushan (1261.1 m), Dayunshan (909.7 m), Xiangyang Mountain Yueyang County (957.2 m), Pingjiang County Mofu Mountain (1595.6 m), Lianyun Mountain (1600.3 meters), all belong to Zhongshan. The major constituent materials are granite and metamorphic rocks. Elevation above 800 meters, the relative height of more than 600 meters, the ground slope is greater than 50 °. Clear cut, river gully density of 3 to 6 km / km, with a high mountain, valley deep, steep slope characteristics. Valley of clouds, the development of modern landforms to flow-based erosion-based. Gully erosion has reached the mouth of Heyuan saddle, water was dendritic and radial distribution.
Medium Low Mountain
For example: Linxiang City, Zhongshan peripheral, Wujianshan area, large Yunshan, Acacia Hill extension part of the screen Fu Shan Mountains, southwest of Lianyun Mountain, Fuxing Mountain, Miluo City Jade Pool Hill, all belong to the low mountain. The main components of metamorphic rocks and granite. 500 to 800 meters above sea level, the relative height of 400 to 600 meters, the ground slope is greater than 30 °. River gully density of 3 to 6 km / km, medium cutting, modern landforms to the formation process of the main line erosion. With steep mountains, ridge obvious, clear context, to the uncertain characteristics. These ridges are mostly rounded, ridge both concave and convex, the mountain was pig dorsal.
Low Mountain
For example: Huarong County Peach Hill area, large Yunshan, Mausoleum Fu Shan, Fuxing mountain periphery, Miluo City, southeast and northeast Zhifeng Shan and the southern Miyan Mountain, Piaofengshan, Shendingshan residual roof. Linxiang City, Chang'an Valley on both sides of Yueyang County, Azabu Mountain and Yueyang Tower District, a small wooden Ridge, all belong to the low mountains. The main composition of the material is granite, metamorphic rocks, sand shale and sand and conglomerate. Elevation 300 to 500 meters, the relative height of 20 meters, the ground slope of 25 ° to 30 °. Cutting slightly, the river gully density of 4 to 6 km / km, ridge clear context, but the more chaotic.
The hills are in the slow rise of the crust. Hilly area of 3435.98 square kilometers, accounting for 23% of the total area. According to the characteristics of surface morphology can be divided into high hills and low hills two subcategories.
High hills
Generally distributed in the front of the mountain area, or mountain extension of the pulse. Linxiang County, Zhongcheng, Rangcun, Pingjiang County, Cen, Wengjiang, Sanyang, Zhongdong and Lianyunshan areas, distributed by the metamorphic rocks (or Phyllite, slate) composed of high hills. Huarong County, horn Hill, a small Mexican area, Linxiang City Zhanqiao, Aries, He Fan, Yueyang County, Mao Tian, Acacia, Gongtian, Gantian, Rao village, Phoenix, Pingjiang County South River, Hongqiao, Zhezhuang, , Si Village, Lo hole, Miluo City Bishi, Gao Fang and other places, the distribution of granite composed of high hills. In addition, Linxiang City, Changan Valley on both sides of the east-west distribution of sand and shale high hills. Pingjiang County Jinlong, continental distribution of the gravel high hills, 200 to 300 meters above sea level, the relative elevation of 150 to 200 meters, the ground slope of 20 ° to 25 °, the local greater than 25 °. River gully density of 4 to 5 km / km. Mound mostly short strip, ridge and rill valley slightly ribbon, arranged in white. Gully more ridge for the ridge fields, mostly dry foot slope. Qiu round muddy, hill ridges gently, base rock local exposed, most of the weathering is more intense, slope residual thick. The process of modern landform development to the main line-based erosion, soil erosion is serious.
Low hills
Mainly in the high hills and the transition to the hills outside the region. Huayong County to the north of the Mahayana Temple, Linxiang City, Nie City, Yueyang County, South Chong, Yuetian, Huang, Dadan, Gan Tian, Lantian, Weidong, Phoenix, Guan Wang, Pingjiang County Sanyang, urn, Tan , The hole, Miluo City safflower, patio, Changle, Gulun, Whitewater and other places, the distribution of metamorphic rocks (phyllite, schist, slate) composed of low hills. Linxiang City, Taolin, Chang Tong, Zhong Fang, Aryi Tian, Pingjiang County Changping Basin in some areas of red sandstone and conglomerate, composed of low hills. Huayong County Ding Shan, Shi Fushan area, Linxiang City Aries, He Fan, Zhan Bridge, Yueyang County, Mao Tian, Weitian, Rao village, Phoenix and new Kaitang area, Pingjiang County South River, Hongqiao, Zhong Dong, Sichuan, Xijiang, Si Village, Lo hole, Mei Xian, Hu Pei, Miluo Cork, Kawamoto Ping, Gao Jiafang and other places, composed of granite composed of low hills.
In addition, there are Linxiang City Changan Valley on both sides, by the Sinian - Cambrian sand and shale composed of low hills. Pingjiang County Jinlong, pulp city, continent and other places by the Tertiary red sandy conglomerate composed of low hills. Linxiang City, Yanglou Division, Yunxi District, and other places there are sporadic distribution of the Cambrian - Ordovician limestone, dolomite composed of low hills, 100 to 200 meters above sea level, the relative height of 60 to 150 meters, Ground slope 15 ° ~ 20 °. River gully density of 5 to 7 km / km. The mounds are criss-free, non-directional, mostly bun-shaped, dome formed short ridge-shaped, Qiudou rounded, staggered valley, Qiujiao ditch, concave comparative development, has been cultivated as paddy fields, some hills for dry land. The process of modern geomorphic process is mainly water erosion, and the gully erosion is very strong, and soil erosion is serious.
In the relatively stable region of the crust, the area is 2689.03 km2, accounting for 18% of the total area, due to the effects of water erosion and physical weathering. According to their morphological characteristics, divided into high-Gang and low post to two sub-categories.
Gao Gangdi
Huarong County, Sanlang weir to the north, send book Ridge, ink mountain, small ear mountain, Fengshan, Miluo City Taolin Temple, Fan home, fire days, Huang, Gu Pei, Pingjiang County stability, Sanyang, Chiayi area 3 ~ 5 Level along the terraces, distributed by the reticulate red soil and gravel layer composed of red soil Gao Gang. Linxiang City, Changling, Pingjiang Pingping edge of the basin, Miluo City Jing, Huang City, fire days and other places, distributed by the purple sandstone, conglomerate, siltstone, mineral conglomerate composed of Gao Gang to. Pingjiang Cenchuan, Xijiang Basin, Miluo City Chuan Shanping, Gaojiafang, Bute, Tongpen, Shaxi, Cork, Gulun, Changle, Patio, Linxiang City, southern granite valley on both sides of the distribution of granite Gao Gang to. Kunshan, Ma Tang, Longwan, five embankment, Pingjiang County, Chestnut Hill, on the Cen, urn River, Sanyang, Miluo River, the Yangtze River Delta, Watershed on both sides of the iron gate above the mountain and Shending, dense rock northwest of Shanxi, distributed by the metamorphic rocks composed of Gao Gang. In addition, Linxiang City Changan Valley tandu part of sand shale Gaogang, Pingjiang County papaya, gantry, pulp city, think of the village, along the Miluo River along the Miluo River, the distribution of sandy conglomerate composed of Gao Gang. Altitude is generally less than 100 meters, the relative height of 30 to 60 meters, the ground slope of 10 ° to 15 °. River gully density of 4 to 6 km / km. Gang body was spread like a bread-shaped or ridge-shaped ridge and ridge arrangement, the top flat.
Low Grounds
Huangshan, Daming, Jingzhou, antlers, Nakasu, Nakamura, Nakamura, Aries, ten steps, bear market, Yang Lin, Gongtian, Pingjiang County, Cangshan, Sanyang, stability, Chiayi, Miluo City Xintang, Baitang, Chu Tong, Taolin Temple, Fan Jiayuan, white water, eastern part of Xiangyin County and Qu Yuan farm parts. Linxiang City, Taolin, Zhong defense, Chang Tong, Aries, Chang'an, Cheng Feng, Xiangyin County quiet and other places, the distribution of the Hongyan composed of low post. Linxiang City, duck bar - Dinghu area and the Chang'an valley to the north side of the distribution of sand and shale composed of low hillock. Miluo City Chuan Shan Ping - Gao Jiafang, copper basin - Bishi Valley to the mountain on both sides of the transition and Baishui Township, Xiangyin County Yuhua, Jinlong, Changkang, distributed by the low granite granite composition. Linjiang City, duck bar - Dinghu to the south of Pingjiang County, Chestnut, Cen, urn, Miluo River Plain and Zhifengshan the junction of the distribution of metamorphic rocks (phyllite, slate) low post, low elevation At 60 meters, the relative height of 10 to 30 meters, the ground slope of 5 ° to 10 °. Modern geomorphic development process to flow surface erosion and gully erosion-based. River gully density of 2 to 3 km / km. Gangding flush, post body mostly bread-like, gentle ups and downs, slightly inclined to the plain. Lateral and plain border, a clear transition; medial and high post to the border, the gradual transition.
The plains are mainly formed by the long-term accumulation of alluvial deposits in the area where the neotectonic movement crust is relatively declining. Area of 4033.55 square kilometers, accounting for 27% of the total area. Mainly distributed in Huarong, Yueyang, Xiangyin, Miluo County (city) and money grain lake, Qu Yuan, Jianxin, Junshan, Huang Gaihu farm. More than 50 meters below sea level, the ground slope is less than 5 °, slightly tilted to the Dongting Lake. River gully density of 1 to 2 km / km. Flat open, deep deposition, contiguous cultivated land. According to the morphological characteristics and material composition of the surface, it can be divided into alluvial plain, alluvial plain and valley alluvial plain.
River alluvial plain
Located in the lower reaches of the Yangtze River and the lower reaches of the Xiangjiang River area, including Huarong County Jiangzhou, Jicheng, Tacheng and Hongshan first part of Linxiang Jiangnan, Huanggaihu farm, Yueyang County, the new wall along the lower reaches of the river, Miluo City Caojiashan below Miluo River, the middle of Quyuan farm, Xiangtang three ponds and Dongtang north, Hunan, capital two water tail. Surface material is mainly composed of river alluvium, less than 40 meters above sea level, the slope is less than 5 °, the ground flat, slightly to the river tilt.
Binhu alluvial plain
Located in the Binhu area, including the Huarong County in the southwest, Junshan Qu Guangxing Chau, Qianliang Lake, build new, Junshan farm, Miluo City from the Lei stone along the east coast of Miluo River, Quyuan farm north and west Xiangyin County in the west of the Xiangjiang River . The surface material is mainly composed of alluvial deposits and Dongting Lake sediments. Altitude is generally less than 30 meters, the bottom is less than 3 °, low-lying. Lake Island, floodplain, wetland widespread.
Valley alluvial plain
Development in the hill, hillock hill valley area. The eastern mountain is the creek birthplace. The general process is short, small flow, erosion, strong, not many floodplain. Hilly terrain is smaller than the terrain, the valley is more open, more meandering development, the prevalence of river sedimentation, the formation of alluvial, alluvial plains composed of the valley. Mainly distributed in the outer edge of Peach Hill, Taolin River, the source Tam River, Xindian River, the new wall on both sides of the river valley, Miluo River and its tributaries, Xiangyin eastern hillock valley. The surface material consists of alluvial alluvium. Elevation is generally below 50 meters, the surface is relatively flat, slightly tilted to the river bed. Slope is generally less than 3 °, near the mountain part of up to 5 °, the valley plains have been turned into farmland.
Dongting Lake is located on both sides of the territory, the Yangtze River along the northern border through the territory, Hunan, capital of water diversion from the southwest of Yueyang City, low-lying East West, rain-rich. Therefore, the water system developed, rivers, lakes, ponds, reservoirs more extensive waters, known as "Dongting Water Village," said. Water area (excluding outer lake) is 2539 square kilometers, accounting for 17% of the total area. The territory of the Dongting water system, the basin area of the city's total area of 90.54%, followed by the Riverside and Poyang Lake water system. There are 273 large and small rivers, 165 lakes. There are many small and medium-sized reservoirs, water diversion canal, water ponds and more. The eastern mountainous area has a water surface of 285.20 square kilometers, accounting for 11.23% of the total water area. The central hilly area has a water surface of 543.74 square kilometers, accounting for 21.41% of the total water area. The western plain has a surface area of 1710.70 square kilometers, accounting for 67.36% . In addition, the outer lake surface area of about 290 square kilometers.
This figure "China's geomorphic zoning online map" shows the legend is as follows:
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