Geographia Technica, No. 2/2009, pp. 11 - 22

GIS IN DETERMINATION OF THE DISCHARGE HYDROGRAPH GENERATED BY SURFACE RUNOFF FOR SMALL BASINS

 M. Domniţa , A. I. Crăciun, I. Haidu

ABSTRACT: A hydrograph model is proposed in which the watershed is decomposed into subareas represented by individual cells. The watershed response is found for each cell and these responses are convoluted to produce the watershed runoff hydrograph. The cell to cell flow path to the watershed outlet is determined from a digital elevation model. A flow velocity for each cell is calculated using Manning’s formula and used in determining the travel time of water through each cell. In this paper a simplified approach is used: the rainfall intensity is considered constant thorough the rainfall event. The velocity field, considered spatially varying but time invariant, and the flow path to the outlet are used to determine the runoff time from each cell to the outlet of the watershed. The responses of each cell with the same travel time to the outlet are summed to produce the hydrograph. An example is shown for the 11 km2 Pârâul Mare watershed in the Apuseni Mountains.
Keywords: hydrograph, runoff, small basin, GIS, rational method

Full article:m_domnita_et_colab_gis_in_determination_of_dis.pdf