TINGKAT AKURASI EMPERICAL AREA REDUCTION METHOD (EARM) UNTUK MEMPREDIKSI KURVA H-V DI WADUK MRICA

Abstract

Abstrak

Sedimentasi waduk merupakan permasalahan yang sangat penting dalam kegiatan operasi dan pemeliharaan waduk. Perkembangan sedimentasi waduk dapat dilihat dari hubungan antara kapasitas tampungan dan elevasi atau sering disebut kurva H-V. Kurva ini dapat dibuat dengan melakukan pengukuran echosounding secara periodik. Namun, dalam beberapa kasus banyak waduk tidak melakukan ini karena pertimbangan biaya, oleh karena itu, perlu digunakan pendekatan model seperti Emperical Area Reduction Method (EARM). Penelitian ini bertujuan untuk mengetahui tingkat akurasi model distribusi sedimen EARM agar dapat digunakan untuk memprediksi kurva H-V.Lokasi penelitian inidi Waduk Mrica yang berada di Kecamatan Bawang, Kabupaten Banjarnegara.Tahapan analisis meliputi menganalisis kondisi sedimentasi waduk, menganalisis prediksi kurva H-V dengan model EARM, dan mengevaluasi kesesuaian model untuk mengetahui tingkat akurasi berdasarkan nilai korelasi (R) dan Relative Mean Error (RME).Waduk Mrica mengalami tingkat sedimentasi yang sangat tinggi dengan laju sedimentasi waduk rerata sebesar 3,951 juta m³/tahun. Laju sedimentasi berangsur mengalami penurunan akibat mulai adanya pengelolaan sedimentasi di Waduk Mrica. Pendekatan dengan model Emperical Area Reduction Method (EARM) untuk memprediksi kurva H-V sangat ideal digunakan di Waduk Mrica. Hasil evaluasi dari prediksi model terlihat nilai korelasi mendekati kondisi ideal (R² = 1) dan nilai RME hanya bekisar antara 0 – 11%, artinya prediksi kurva H-V dengan model EARM menunjukkan korelasi yang sangat kuat dengan data lapangan dari pengukuran echosounding.

Kata kunci: Distribusi Sedimen, Empirical Area Reduction Method (EARM), Kurva H-V, Sedimentasi Waduk, Waduk Mrica

Abstract

Reservoir sedimentation is a very important issue in reservoir operation and maintenance activities. The development of reservoir sedimentation can be seen from the relationship between the reservoir capacity and elevation or often is called H-V curve. This curve can be made with periodic echosounding measurements. However, in some cases many reservoirs don’t perform due to cost considerations,therefore, it requires a modeling approach such asEmperical Area Reduction Method (EARM). This study aims to determine the level of accuracy of EARM sediment distribution model so that it can be used to predict the H-V curve. The location of this research was in Mrica Reservoir, Bawang District, Banjarnegara Regency. The stages of analysisinclude: analyzing the sedimentation conditions ofreservoir, analyzing the H-V curve prediction withEARM model, and evaluating the suitability of the model to determine the level of accuracy based on the correlation value (R) and Relative Mean Error (RME). As results, Mrica Reservoir experienced a very high sedimentation rate with an average reservoir sedimentation rate of 3,951 million m³/year. The sedimentation rate has gradually decreased due tosedimentation management in the Mrica Reservoir. The Emperical Area Reduction Method (EARM) approach to predict the H-V curve is ideal for used inMrica Reservoir. The evaluation results ofprediction model show that correlation value approach ideal conditions (R² = 1) and RME value is only in the range of 0 - 11%, It meaning thatH-V curve prediction with the EARM model shows a very strong correlation with field data from echosounding measurements.

Keywords: Sediment Distribution, Empirical Area Reduction Method (EARM), H-V Curve, ReservoirSedimentation, Mrica Reservoir.