Upstream
Danjiangkou to the upper reaches of the river is usually upstream, Danjiangkou to Zhongxiang Nianpan between the middle reaches of the river section, downstream of the following Nianpan mountain.
The upper reaches of the upper reach of the upper reaches of the Hanjiang River are 956 km in length and the catchment area is 95,220 km2. The main stream is in the east-west direction, crossing between Qinling and Dabashan. The canyon basin alternates along the river bed. The river bed is composed of pebbles, gravels and bedrock. Than drop large. The main stream from Yunxi into Hubei Province, the North Qinling Mountains, south Wudang Mountains, river bend coefficient of 1.78, the average ratio was reduced to 0.6 ‰, is a mountain wandering river, rapids, water resources, its reserves Of the total amount of water to build the theoretical capacity of 6800, and dam construction conditions, the development of the Han River is an important river water resources.
According to the river morphology, the main stream can be divided into six sections: Heyuan - Wuhou town: valley narrow, steep valley on the north coast, the South Bank to ease. From the Ligangba to Weijiaba, along the river to form a small basin - Da'an Basin, the basin width of 2 to 3 km, the modern river channel width of 1 km, the river by the sandy gravel composition, erosion and deposition changes significantly.
Wuhou Town - Longtingpu section: the river into the river basin, the river and the beach wide, less than the drop, the water flow slow, swing around the river uncertainties, erosion and deposition changes significantly. River bed is composed of sand pebbles, river silt shallow, more sandbar cross-flow, Hanzhong in the southwest of the village beach is built in the river sandbar. Basin about 100 km from east to west, north to south 5 to 10 km wide. Praise west of the river, low water when the river is only 30 meters wide, when the flood width of 400 to 700 meters. Praise east of the river, low water when the river width of 300 meters, the river flood 1 to 2 km wide. There are four terraces in the basin, the ground flat, fertile soil, rich in water resources, water conditions, agricultural development, a small Jiangnan known.
Longdingpu - Weimen section: 53 km long, for the Precambrian granite,granodiorite, gabbro and amphibolites formed by the upper reaches of the Hanjiang River Canyon, of which the Gap and the Golden Gap of the most famous . Gap Gap from small to Central Pearl Temple, 23 km long; Golden Gorge, also known as the Grand Canyon, from the Central Temple to Weimen, 30 km long. Canyon on both sides of the mountain 300 to 400 meters above the river bed, valley slope 5070 degrees, the river width - less than 200 meters, the narrowest only 30 meters, exposed bedrock in the river, beach insurance a lot to turtle beach, Garlic, etc. the most dangerous.
Weimen - Shiquan segment: 51 km long, the river bend, steep left bank, right bank slow, wide river in more than 200 meters, 500 meters wide river valley. Three flower stone to tea between the town of Qili dam - belt, valley open, wide 350 to 500 meters. Tea town and into the upper Proterozoic Xixiang group and the Cambrian Ordovician Donghe group formed by the Canyon area, Shuicheng Tan and more, but the degree of steepness than gold Gap, valley width of 200 meters, river width 100 I meters, 11 beach insurance.
Shiquan - Ankang section: this section of the canyon, basin staggered, the two sides of the mountain 300 meters above the river, valley width of 200 to 500 meters, 200 to 300 meters wide river. Moon River Ankang basin, river valley is spacious, become agricultural developed area. River bed is composed of sand pebbles, beach insurance 31.
Ankang-Baihe section: This section is the Lower Paleozoic metamorphic rocks and limestone valleys, of which Xunyang Baihe gorge is more narrow. Mountain 200 meters above the river, valley width of 200 to 500 meters, the river width of 250 to 350 meters, the river bed is composed of pebbles, beach insurance 24.
Middle section of the river
Hanjiang River from Danjiangkou to Naban Shanjiang section, a total length of 223 km, the catchment area of 45120 square kilometers, the river flows through the hills and open valley basin, the average ratio of 0.19 ‰, river bed width, water scattered, the size of Jiang Xinzhou 20 I, is wandering type river. The Han River and the Tanghe River after the South River, the amount of water, sand volume increased, when the bed when the red silt, and by the two sides of the mountain node control, different width, low water channel width of 300-400 meters, the flood period of 2-3 Meters, the most wide up to 5-6 km.
This section of a total of 143 sandbar size, sand 38, an average of 1.7 km per sand or sand that is a sand and sand are often changing, such as the three official Hall near Rao Jia Ying to the Royal embankment area, 1944 Sandbar 6, to 1953 has washed away 2, but there are new sandbar in the place there. In this paragraph Xiangyang above river bed quality is boulder, coarse, fine sand composition, Xiangyang following sandy river bed. River valley along the river in addition to local locations (such as the old Longyang embankment), almost all non-embankment, therefore, often affected by floods, natural dike along the river gradually increased, and the plain part of the river from the lower terrain, The lowest edge, resulting in inverted topography of the valley, the local residents are also aware of this point, the "high Mo than the river, low Mo than the mountain" proverb.
Downstream section
The river reaches the whole length of 398 km, catchment area of 18660 square kilometers, the river than the average drop of about 0.09 ‰, water flow slowed down, the bending coefficient of 1.81, is a meandering nature of the plains River course. Riverbed for sandy, cross-strait built a tight embankment. In the Qianjiang Ze mouth leading Shui, the Han River diversion - East Jinghe, flood season can be divided Hanjiang part of the flood, the maximum water capacity of 5600 cubic meters / second, the main stream from the Metro following, river development, known as " And the cross-strait embankment and riverbed section, showing the characteristics of the width under the narrow, so the safety discharge capacity of the river, the more the smaller the estuary, in case of flooding, should vent poor, easily collapse. According to statistics: the Hanjiang River downstream branch, 1822 - 1967 146 years in a total of 73 years, 1931-1955 of which 25 years, 15 years of collapse, the collapse of the opportunity, has reached 3 years.
This section along the banks of the 35 meters above sea level for the majority of the plains and many lakes, plains into a ribbon, parallel with the river. 35 to 50 meters for the river terraces, hillock and hillock. Hanjiang, East Jinghe, Yangtze River and other large rivers along the terrain is generally high, the river is often formed between the depression, water accumulation of lacustrine lacustrine belt. For example, the left bank of the Hanjiang River, between the main stream and the northern hinterland of the Tianmen River Diaocha Lake depression area, the right bank of the Hanjiang River and the East River between the fluent lake row depression, East Jinghe and the Yangtze River between the Jing River River) Honghu depression, these depressions are generally east-south direction. In the plains and terraces adjacent to the terrain is also very low, often during the lake spread, as hillock hillside depression, such as Zhongxiang Da Lake, Tianmen White Lake, Xiaogan Tongjiahu, Boar Lake and so on.
The map comes from the "China Geographic Atlas" in the Han River Basin and water conservancy
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