The Effect of Ameroro Reservoir on River Morphology Stability Using Regime Theory

Abstract

The stability of river geometry is one of the considerations to determine whether a watershed is good or not. Ameroro River is a tributary of Konaweha River located in Konawe Regency, Southeast Sulawesi. The Ameroro River model uses river measurement data along 43.5% of the length of the main river and uses geological data as a model for sediment transport. In hydrological analysis using the Log-Normal distribution and daily discharge modeling with the Sacramento method calibrate by 9 years of observational data with a match rate of 52.9% and a calculation process was carried out with the help of the HECRAS program. The results of the modeling were checked and approached using 3 methods of regime theory, Blench, Lacey and Modified Regime as a reference for calculating river stability as seen from the cross-sectional width of the river. It was found that reservoir affect changes in riverbed elevation, water level elevation and degradation/aggradation compared to existing conditions. The existing condition has a stable river cross-section more than the condition of the reservoir but only 7.29% of the total river cross-section is reviewed. For overall of river, it was found that the reservoir affected the stability of the river is closer to the calculation results of 3 regime theory methods compared to existing conditions tested by NSE, RMSE and CORRELATION methods