Estimation of Sediment Yield in a Small Urban Ungauged Watershed based on the Schaffernak Approach at Sugutamu Watershed, Ciliwung, West Java

Abstract

The sediment yield is defined as the amount of sediment discharged by an area for a given period of time. Schaffernak proposed to estimate sediment yield in a watershed based on a sediment duration curve. The research objective is to test the applicability of a modified Schaffernak approach in estimating annual sediment yield in Sugutamu, a small urban watershed subsystem of the Ciliwung River where hardly any necessary data is available. The discharge-duration curve is developed based on daily runoff simulation using a hydrological model WinTR-55, while the sediment rating curve is derived based on field surveys and is developed only for a total suspended solid. The results of field surveys conducted in January 2015 were used for calibrating the physiographical parameters of the watershed as input data for WinTR-55, and the simulation was for the year 2014. Both calibration and simulation processes utilized the rainfall data from a nearby automatic rainfall recorder. The quantification of sediment yield resulted in 108.5 tons/km 2 /year, which is acceptable when compared to the results of similar studies. The results showed that sediment yield from ungauged watershed are possible to be quantified using modified Schaffernak approach in combination withWinTR-55 application. Further study is needed in order to validate the applicability of the approach in similar conditions.

Use of the WinTR-55 Hydrologic Model on Determination of Flood Peak Discharge: The Case of Kirklareli Vize Stream and Samsun Minoz Stream Watersheds

“…According to Alkan (2016), the WinTR-55 model tends to determine a larger peak flow value than other determination methods of synthetic peak flow. According to Roberts et al (2009) and Sutjiningsih et al (2015) the WinTR-55 model requires fewer input data and is easy to use to determine peak flow and sediment yield. On the other hand, the model produces more reliable results in small watersheds.…”

“…Results showed that the south of the campus was durable against the stormwater in terms of hydrologic modeling. Sutjiningsih et al (2015) aimed to test the feasibility of a modified Schaffernak approach for annual sediment yield estimation in Sugutamu, a small sub-basin in the Ciliwung River. The results showed that it is possible to quantify the sediment yield by using the modified Schaffernak approach with the WinTR-55 application.…”

“…He modeled that the water depth in the residential area is 5 m and wide of the flood spread is 250 m. Thus, he made the flood analysis of Turkkose Stream with the model and determined the areas that could be affected by the flood in the residential area. Sorman et al (2020) compared the HEC-HMS and HBV model between 2008-2015 in Aras Basin in Turkey. The performance of both models was evaluated with Nash-Sutcliffe.…”