Pemodelan Hujan Aliran Menggunakan Software HEC-HMS Berdasarkan Data Curah Hujan Satelit CHIRPS Pada DAS Mayang

Abstract

The Mayang Watershed is one of the large watersheds located in the Jember Regency. The Mayang River Basin is an area prone to illegal logging, leading to frequent occurrences of floods. The insufficient land cover to counterbalance the high rainfall results in water overflow. Rainfall modeling is crucial to assess the reliability of a watershed. One challenge in rainfall runoff modeling is the availability of rainfall data in each watershed, which is not always complete regarding river discharge that can be used for flood hydrograph analysis, especially in ungauged areas. One solution to address this issue is by utilizing the CHIRPS satellite (Climate Hazards Group Independent Precipitation with Stations). This study employs the Green and Ampt method and SCS CN for the runoff model. The calibration results for Nash Sutcliffe and R^2 are 0.454 and 0.515, respectively. For CHIRPS satellite rainfall data, the corresponding Nash Sutcliffe and R^2 values are 0.402 and 0.462. Calibration and validation results indicate that the reliability of the model using observed rainfall data is better than the model using satellite rainfall data.