发布网友 发布时间:2024-07-03 01:50
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热心网友 时间:2024-07-12 20:51
Tiaohe, situated in the southern part of Gansu Province, is the second largest tributary to the Yellow River上游 (after the Huaihe), originating from the western slopes of the Qingshui Mountain in Qinghai Province's Hetian Mongolian Autonomous County. It flows through counties such as Luxu, Lintan, Zhuoni, Minxian, and Lin Tao, eventually merging into the Yellow River within the Yongping County boundary.
The main river runs 673 kilometers in length, covering a vast area of 25,527 square kilometers. The river's course showcases a unique "L" shape, with its上游 stretching from Xizhai in Minxian to the west and east, where it turns north-west. This segment, 384 kilometers long, has a gentle slope of 4.9‰, characterized by wide river valleys and flat terrain, supporting extensive grasslands. The water flow is steady, clear, and erosion is minimal, maintaining a stable riverbed.
The middle section, from X塞 to the Hai奠峡 (Draconic River Mouth) in Lin Tao, is 148 kilometers long, with an average gradient of 2.8‰. Geologic faults play a significant role here, resulting in numerous twists and turns and deep gorges. Forests and grasslands are prevalent, supporting robust water conservation and low sediment levels. The water intensity increases, with rapid currents and abundant hydroelectric potential.
The下游, below Hai奠峡, extends 141 kilometers, with a 2.5‰ gradient. The river widens and features more sandy banks, flanked by yellow soil hills and poor vegetation. Water erosion is a prevalent issue in this part.
The Tiaohe Basin is bordered by mountains, with the Bird Mouse and Ma Qian Shan separating it from the Wei and Zuli rivers to the east, and the Chang岭 Mountain and Daxiahe River to the west. To the north, it borders the Yellow River mainstream, and to the south, it terminates against the Xiqu岭 mountain range.
Tiaohe's annual natural flow volume stands at 53 billion cubic meters, with 72% of that originating from the upper and middle reaches, despite occupying only 59% of the total basin area. Its average annual runoff per square kilometer, 250,000 cubic meters, is 2.3 times the average for the Yellow River. Tiaohe is a river with low sediment load, transporting 28.8 million tons of sand annually, with an average sediment concentration of just 5.5 kilograms per cubic meter, a fraction of the average for the Yellow River.
洮河是黄河水系上游的重要支流,发源于青海省河南蒙古族自治县西倾山,曲折东流过碌曲、临潭、卓尼县城南,至岷县茶埠急转向西北,出九甸峡与海奠峡后,穿临洮盆地,于永靖县注入刘家峡水库。全长673公里,流域面积2.55万平方公里。沟门村站多年平均流量172立方米/秒,年径流量53亿立方米,5~10月占75%以上,为甘肃中部提供了丰富的水资源。