Minimum flow estimated by the froude number

Following the development and management of water resources to satisfy the human demand, the quantity and quality of flow in streams change in both space and time. With increasing recognition of streams being fundamental to human existence, concerns for the effect on the stream ecosystem have been raised by government, biologists and private citizen groups interesting in preserving the natural integrity. It is necessary to maintain instream minimum flows to provide for preservation of wildlife and other environmental values. This study proposed a method for estimating the minimum discharge needed to maintain good biological quality. It is based on the Instream Flow Incremental Method (IFIM) that is a habitat based tool used to evaluate the environmental consequences of various water and land use practices. However the habitat suitability curves are obtained by the Froude number calculated by a two-dimensional computational fluid dynamic model. Then the habitat suitability curves are used to determine the weighted usable area. The minimum flow will be 80 percent of the maximum weighted usable area. The available data of the Fungane Creek is used to illustrate the proposed. The results show that the minimum flow of stream can be easily and efficiently determined by the Froude number.