1.   Purpose and objectives

     A conceptual model using storm rainfall and evaporation to estimate runoff. Intended for flood forecasting.

2.   Description

     The model uses the concept of storage excess to compute the runoff volume and takes into account the non-uniform distribution of soil moisture over the basin. A three layer model is used to compute actual evaporation. Unit hydrographs are used to distribute computed runoff from the
sub-basins, which are then combined by a stream routing procedure to give the basin outflow. The model structure is simple, involving about ten parameters. The time step used is one day, but this could be changed.

3.   Input

     Rainfall data and evaporation records.

4.   Output

     Forecast basin outflow hydrograph.

5.   Operational requirements and restrictions

     The model may not be used in arid regions. A computer program in FORTRAN is required for calibration. It can be operated for forecasting by a computer or even a scientific calculator. Professional hydrologists with modelling experience are required.

6.   Form of presentation

     Program on floppy diskette plus user's manual.

7.   Operational experience

     Has been used successfully at over 100 sites in the humid regions of China.

8.   Originator and technical support

     Hohai University (former East China College of Hydraulic Engineering), Nanjing.

9.   Availability

     From the HOMS National Reference Centre for China.

10.  Conditions on use

     Cost of reproduction and mailing.