Effect of differences in runoff coefficient value on channel dimensions at open pit mines.

One of the main problems in open pit mining is the presence of water. Water in the mining area can disrupt mining operations and, in consequences, the production target will not be achieved. The mine drainage system is one part of the system used to overcome the presence of water. The rational method is the method most widely used by hydraulic engineers to estimate the discharge. The open channel dimension is designed based on the discharge estimation. Runoff coefficients are critical parameters for rational methods. There are several sources of literature determining the value of runoff coefficients, such as the approach of the American Society of Civil Engineering (ASCE), Schwab, Perry, and Gautama. In this paper, we examine the method selection effect of open channel dimension for determining the runoff coefficient value in the same conditions both of the rain catchment area and the rainfall intensity. The result is Gautama's coefficient value is the closest compare to real condition on the field. [ABSTRACT FROM AUTHOR]