| Summary: | 碩士 === 萬能科技大學 === 工程科技研究所 === 96 === Considering the channel slope and vegetated revetment, this research makes the according channel test and analyzes the hydraulic properties on trapezoid channel. The result analyzed from test data shows that Manning’s coefficient of vegetated revetment (nw) increases and then decreases with the channel slope (S) at the same flux (Q) and channel slope (Sw). The nw value is the largest at Sw = 10.4 and then approaches a constant value. Under the same flux, the nw value decreases with S. In addition, the smaller flux has a larger influence on the nw value. Under the same S, the nw value first decreases and then increases with Q. When S = 0.04, the nw value significantly increases with Q. In addition, the larger S has a larger influence on the nw value. The relations of Manning’s coefficient of channel (n) and S have the similar results for those of the nw value and S. However, the n value is smaller than that of the nw value. Applying the linear regression analyses, the relations of the Froude number (NF) and nw and n are given as nw = -0.0029NF2 - 0.0161NF + 0.0667 and n = 0.0049NF2 - 0.0292NF + 0.0556, respectively. In addition, the relation of n - nw is given as n = 2.2544nw2 + 0.7825 nw - 0.0109. The regression functions are helpful to design the practical application in a hydraulic engineering. The influence factors of the hydraulic and channel properties are considered on ecological channel. Applying the dimension analysis, the influence parameters can be changed to dimensionless parameters. The multiple regression analysis of the SPSS software are used to obtain the functions of Manning’s coefficient and dimensionless parameters and the final results are given as and . The percentage differences between the roughness coefficients obtained by the separation-area method and the multiple regression model are -4.89 ~ 7.39 % for the nw valve and -5.29 ~ 6.39 % for the n valve. The result shows that this model can appropriately interpret the test data. The regression functions are helpful to design the practical application in ecological engineering. Under the known of hydraulic conditions for trapezoid channel, these functions can be used to estimate effectively the roughness coefficients of the vegetated revetment and channel on trapezoid channel. In addition, it can promote conveniently the hydraulic design of ecological engineering.
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