ANALISA PARAMETER HIDROGRAF SATUAN SINTETIK METODE NASH DAN SOIL CONSERVATION SERVICE (SCS)

The construction of water constructions is increasing over time to prevent flooding,
raising the water level, as well as assisting the management of water resources. But
the planning requires debit data for 20 years which is very difficult to obtain.
Therefore, there is a Synthetic Unit Hydrograph (HSS) method to help analyze without
using rainfall data and only using watershed characteristics for hydrological analysis.
This research will analyze the synthetic hydrograph parameter using the Nash and Soil
Conservation Service (SCS) method and compare it with the data from the AWLR
Gemawang in the Code River Sub-watershed. Comparisons were made to determine
which method was suitable for the Code River sub-watershed at the Gemawang AWLR
station. The suitability index or R² of the two methods shows the results that are close
to one or very related. The regression angle from the variation of SCS method is 38˚,
when the rising time got 36,5˚ and 38,6˚ for the recession time. The variation of Nash
method got 40,1˚ for one hydrograph data, 40.6˚ for the rising time, and 43,3˚ for the
recession time.