Studi Perbandingan Model Horton dan Model Philip Terhadap Laju Infiltrasi di DAS Lesti, Kabupaten Malang

Pramestiningrum, Novita and Dr. Eng. Donny Harisuseno, ST., MT. and Jadfan Sidqi Fidari, ST., MT. (2021) Studi Perbandingan Model Horton dan Model Philip Terhadap Laju Infiltrasi di DAS Lesti, Kabupaten Malang. UNSPECIFIED thesis, Universitas Brawijaya.

Abstract

DAS Lesti, Kabupaten Malang mempunyai permasalahan yang komplek terhadap kerusakan lahan, erosi, dan tanah longsor, fluktuasi debit sungai dan sedimentasi yang cukup tinggi disebabkan oleh bentuk topografinya sebagian besar berombak sampai bergelombang dan berbukit sampai bergunung dan besarnya intensitas curah hujan yang tinggi, selain itu DAS Lesti juga mengalami alih fungsi lahan yang besar akibat pesatnya pembangunan di era modern ini, sehingga mempengaruhi laju infiltrasi yang terjadi di DAS tersebut. Berdasarkan peristiwa tersebut, dilakukan studi untuk mengetahui besar laju infiltrasi menggunakan Model Horton dan Model Philip, kemudian didapatkan model yang memiliki prediksi paling sesuai dengan pengukuran di lapangan. Hal ini dilakukan guna mengetahui besar limpasannya dan juga sebagai upaya konservasi DAS Lesti. Pengambilan data infiltrasi berupa hubungan antara waktu dan besarnya penurunan air di titik-titik pengukuran menggunakan alat Double Ring Infiltrometer, kemudian nilai laju infiltrasi dihitung menggunakan Model Horton dan Model Philip. Selanjutnya, dari hasil yang diperoleh dari kedua model masing-masing akan dibandingkan dengan pengamatan laju infiltrasi di lokasi studi untuk melihat kesesuaiannya dengan menggunakan proses uji validasi. Uji validasi yang dilakukan menggunakan NSE, Koefisien Determinasi, Kesalahan Relatif, MAE dan RMSE. Dari hasil uji validasi diambil model yang paling sesuai diterapkan di lokasi studi. Berdasarkan hasil pengukuran dilapangan menunjukkan bahwa laju infiltrasi terbesar pada titik 4 dan titik 11 yaitu sebesar 15,0 mm/menit, berdasarkan klasifikasi U.S. Soil Conservation, termasuk dalam kategori cepat. Sedangkan hasil terendah yaitu pada titik 12, dengan nilai sebesar 4,0 mm/menit, berdasarkan klasifikasi U.S. Soil Conservation, termasuk dalam kategori agak cepat. Untuk perhitungan laju infiltrasi menggunakan Model Horton dan Model Philip, didapatkan hasil bahwa pada semua titik nilai infiltrasi awal dan akhir yang dimiliki model Horton lebih mendekati nilai lapangan. Kemudian untuk hasil analisis uji validasi yang telah dilakukan untuk kedua model yang digunakan, didapatkan bahwa model perhitungan yang dianggap cocok adalah Model Horton. Laju infiltrasi model Horton menggambarkan bahwa model ini lebih mendekati laju infiltrasi pengukuran, sehingga lebih dapat digunakan untuk mengestimasi infiltrasi di lapangan dibandingkan dengan model Philip.

English Abstract

Lesti watershed, Malang Regency has complex problems with land damage, erosion, and landslides, fluctuations in river discharge and sedimentation are quite high due to the shape of the topography, mostly wavy to wavy and hilly to mountainous and the amount of rainfall intensity is high. The Lesti watershed also experienced a large land conversion due to the rapid development in this modern era, thus affecting the rate of infiltration that occurred in the watershed. Based on these events, a study was conducted to determine the infiltration rate using the Horton Model and Philip's Model, then obtained a model that had the most appropriate predictions with measurements in the field. This is done to determine the amount of runoff and also as an effort to conserve the Lesti watershed. Infiltration data is retrieved in the form of the relationship between time and the amount of water decreased at the measurement points using a Double Ring Infiltrometer, then the value of the infiltration rate is calculated using the Horton Model and the Philip Model. Furthermore, from the results obtained from the two models, each will be compared with the observations of the infiltration rate at the study site to see its suitability using the validation test process. Validation tests were carried out using NSE, Correlation Determination, Relative Error, MAE and RMSE. From the results of the validation test, the most suitable model was chosen to be applied at the study site. Based on the results of field measurements, it is shown that the largest infiltration rate at point 4 and point 11 is 15.0 mm/minute, based on the U.S. classification Soil Conservation, is included in the fast category. While the lowest result is at point 12, with a value of 4.0 mm/minute, based on the U.S. classification. Soil conservation is included in the rather fast category. For the calculation of the infiltration rate using the Horton Model and the Philip Model, the results show that at all points the initial and final infiltration values owned by the Horton model are closer to the field value. Then for the results of the validation test analysis that has been carried out for the two models used, it is found that the calculation model that is considered suitable is the Horton Model. The Horton model is closer to the infiltration rate than the measurement so it can be used to estimate the infiltration that occurs in the field compared to the Philip model.

Other obstract

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Item Type:	Thesis (UNSPECIFIED)
Identification Number:	0521070275
Uncontrolled Keywords:	Kata kunci: double ring infiltrometer, laju infiltrasi, model horton, model philip, uji validasi.
Subjects:	600 Technology (Applied sciences) > 627 Hydraulic engineering > 627.5 Reclamations, Irrigation, related topics > 627.52 Irrigation
Divisions:	Fakultas Teknik > Teknik Pengairan
Depositing User:	yulia Chasanah
Date Deposited:	18 Feb 2022 02:24
Last Modified:	09 Oct 2024 06:49
URI:	http://repository.ub.ac.id/id/eprint/189817

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