多沙河流水庫上游河道系統橫向演變之研究

Lateral Fluvial Processes in the Upper Reaches of Reservoir in River System with Hight Concentration

龐炳東(Bingdong Pang)

《中華水土保持學報》 28卷3期 (1997/09) Pp. 201-210

https://doi.org/10.29417/JCSWC.199709_28(3).0004

摘要

多沙河流修建水庫影響庫區河道演變，建庫前河道系統遵循不同的演變規律。興建三門峽水庫後的15年間赤水河河口至陳村河段發生了7次自然裁彎，三門峽水庫改建後20年間卻沒有發生一次自然裁彎。這是一個非常有趣的現象。本文利用渭河下游河道的實測資料，對比興建三門峽水庫前後以及三門峽改建前後渭河下游河道系統棋向演變規律的變化，總結出如下幾個影響因素：（1）局部侵蝕基準面的作；（2）河道縱向變化影響河道橫向演變；（3）新淤灘地泥沙組成影響河道橫向演變；（4）主槽斷面形態影響河道橫向演變；（5）來水來沙和高含沙洪水的作用。本文利用紅山水庫的資料印證了從三門峽水庫得出的河道系統的演變規律。

關鍵字

多沙河流 ； 橫向演變 ； 洪水比降 ； 彎曲系數 ； 泥沙組成

並列摘要

The reservoir of the river with high concentration has influences of fluvial process. There are seven natural cutoffs occurred in the lower Wei River from 1961 to 1975. After the reconstruction of the Sanmenxia Project the natural cutoffs in the lower Wei River did not occur from 1976 to 1996. By the analyses of the field observed data, it if found that the above- mentioned phenomenon is caused by the following factors: (1)The rise of bed elevation serves as a local bane level to the river; (2)The changes of the river slope exert an influence on the lateral fluvial processes: (3) The bed material of the new flood-plain became loose, incoherent and easy to be eroded; (4) The discharge capacity at the bankfull stage was reduced. It provided more chance for the flood inundate its flood-plain; (5)When the kinetic line of over-bank flood with hyperconcentration coincides with the ditch, the ditch may more probably develop into a new main channel and the rare rainfall from 1976 to 1990 effects on the lateral fluvial processes. The conclusions drawing from Sanmenxia Reservoir are verified by the data of Hongsan Reservoir.

並列關鍵字

River with High Concentration ； Lateral Fluvial Processes ； Flood Surface Slope ； Bend Coefficient ； Bed Materials