UM-11 : Hydrologic flood routing

Abstract

This user manual provides description of the capabilities of the hydrologic flood routing package programme developed at the National Institute of Hydrology. The following hydrologic flood routing methods have been included in the package:

1) Muskingum method(single reach);

2) Lag and route method;

3) Muskingum method(multiple reach);

4) Two parameter gamma distribution method(Nash model); and

5) Three parameter Gamma distribution method.

The theoretical basis, advantages, limitations and data requirements of each of these methods have been described. The computer programme is written in FORTRAN IV and in a single execution of the programme only any one of the above routing methods can be opted. The programme can be used either (i) for estimating the parameters of the required routing method using moment matching technique, given the information of inflow, outflow and lateral inflow for the reach, or (ii) for computing the outflow hydrograph using any one of the methods with given inflow information and the parameters required for the particular method. The data input conventions and programme output description are explained. Test examples are given for the routing methods incorporating example input data and the corresponding output generated by the programme. The input description including the description of each card and input variable are explained. The assumption regarding the shape of the pattern hydrograph will be somewhat crucial in the successful application of these methods for routing the flood along the reach, when the contribution of the lateral inflow volume within the the reach is significant.