Consequences of estimation errors in hydrologic design

Short description: 

Practicing engineers often use the rational method and a simplified, triangular hydrograph shape for reservoir sizing. Both requires the estimation of time of concentration. The peak and volume of the inflowing flood is in linear and inverse linear relationship to the time of concentration, respectively. This means, that the overestimation of time of concentration might lead to the oversizing of the outflow structure, and underestimation of the height of the dam. However, we know that the most commonly used empirical equation in Hungary gives inadequate values for time of concentration in many cases.


The student needs to assess the effect of estimation error regarding the sizing of a reservoir at a study area. The main tasks include: choosing a study sight; catchment delineation and assessment of the most important catchment parameters; calculating the design flow, and sizing the outflow structure. A sensitivity analysis needs to be evaluated regarding the design flow estimation using the rational formula, for both time of concentration and runoff coefficient estimation. Beside the rational method, other empirical design flow estimation procedures might be evaluated.  The results should be interpreted from including financial and engineering aspects.


Software requirements: ArcGIS/QGIS, Matlab/Excel (optionally HEC-HMS)

Suggested level: 
BSc level