Abstract |
Information is sparse on the retardance of flow through upright stems of vegetation. Studies were conducted on a smooth flume in which cylindrical retardance elements were inserted at various regular spacings. The effects of pattern of spacing, diameter of elements, spacing of elements, slope and flow rate on Manning's coefficient were determined. Linear, quadratic and logarithmic response surfaces were calculated. Multiple correlation coefficients usually greater than 0.97 were obtained. The linear multi-variable model and the exponential model gave comparable standard deviations. A quadratic model gave slightly improved estimates, but it results in a more complex equation with eleven coefficients. (Author) |