Pemodelan Spatial Extreme Value Pada Tinggi Gelombang Air Laut di Banyuwangi dengan Model Smith dan Geometric Gaussian

Azzahra, Annisa Fathimah (2024) Pemodelan Spatial Extreme Value Pada Tinggi Gelombang Air Laut di Banyuwangi dengan Model Smith dan Geometric Gaussian. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Banyuwangi menghadapi tantangan serius terkait Bencana Pesisir, dengan risiko tinggi terhadap gelombang ekstrem dan abrasi pada tahun 2022. Oleh karena itu, pemahaman terkait karakteristik dan perilaku gelombang sangat penting untuk mitigasi bencana. Analisis spasial dilakukan di empat lokasi rawan bencana pesisir di Laut Banyuwangi menggunakan metode Spatial Extreme Value dengan pendekatan Max-Stable Process model Smith dan Geometric Gaussian. Data yang digunakan adalah data tinggi gelombang air laut periode 1 Januari 2019 – 31 Desember 2023. Pemilihan nilai ekstrem menggunakan metode Block Maxima. Persentase yang digunakan adalah 80% untuk data training dan 20% untuk data testing. Data training mengikuti distribusi Generalized Extreme Value dan tidak terdapat tren (stasioner). Data training kemudian ditransformasikan ke unit margin frechet untuk menghitung koefisien ekstremal. Koefisien ekstremal yang dihasilkan menunjukkan adanya dependensi yang cukup kuat antar lokasi. Model trend surface terbaik adalah model dengan parameter lokasi yang memiliki faktor koordinat latitude dan skala yang memiliki faktor koordinat longitude. Estimasi parameter spasial model Smith dan Geometric Gaussian tiap lokasi dilakukan dengan metode iterasi numerik Nelder-Mead dan BFGS Quasi Newton, serta dilakukan perhitungan return level unit margin frechet dan GEV. Evaluasi model dilakukan dengan menghitung nilai MAPE, SMAPE, dan RMSE pada masing-masing model dan metode iterasi. Nilai MAPE, SMAPE, dan RMSE pada model Smith dengan metode iterasi Nelder-Mead sebesar 0,23912%, 0,23873%, dan 0,01575, sedangkan model Geometric Gaussian sebesar 0,32274%, 0,32212%, dan 0,02001. Estimasi return level Tinggi Gelombang Air Laut lima tahun mendatang di keempat lokasi perairan tergolong dalam kategori ekstrem.
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Banyuwangi faces serious challenges related to Coastal Disasters, with a high risk of extreme waves and abrasion by 2022. Therefore, an understanding of wave characteristics and behavior is essential for disaster mitigation. Spatial analysis was conducted in four coastal disaster-prone locations in Banyuwangi Sea using Spatial Extreme Value method with Max-Stable Process Smith and Geometric Gaussian model approach. The data used is sea wave height data for the period January 1st, 2019 - December 31st, 2023. Extreme value selection using the Block Maxima method. The percentage used is 80% for training data and 20% for testing data. The training data follows the Generalized Extreme Value distribution and there is no trend (stationary). The training data is then transformed to frechet margin units to calculate the extremal coefficient. The resulting extremal coefficients indicate a fairly strong dependency between locations. The best trend surface model is a model with location parameters that have latitude coordinate factors and scales that have longitude coordinate factors. The estimation of the spatial parameters of the Smith and Geometric Gaussian Models for each location was carried out using the Nelder-Mead and BFGS Quasi Newton numerical iteration methods, and the calculation of the return level of the frechet and GEV margin units. Model evaluation is done by calculating the MAPE, SMAPE, and RMSE values for each model and iteration method. The MAPE, SMAPE, and RMSE values of the Smith Model with the Nelder-Mead iteration method are 0,23912%, 0,23873%, and 0.01575, while the Geometric Gaussian Model is 0,32274%, 0,32212%, and 0.02001. The estimated return level of the Sea Wave Height in the next five years at the four water locations is classified in the extreme category.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Max-Stable Process, Model Geometric Gaussian, Model Smith, Return Level, Tinggi Gelombang Air Laut ============================================================ Geometric Gaussian Model, Max-Stable Process, Return Level, Sea Wave Height, Smith Model
Subjects:	Q Science > QA Mathematics > QA246.8 Gaussian Q Science > QA Mathematics > QA276 Mathematical statistics. Time-series analysis. Failure time data analysis. Survival analysis (Biometry) Q Science > QA Mathematics > QA401 Mathematical models.
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Actuaria > 94203-(S1) Undergraduate Thesis
Depositing User:	Annisa Fathimah Azzahra Azzahra
Date Deposited:	25 Jul 2024 03:49
Last Modified:	25 Jul 2024 03:49
URI:	http://repository.its.ac.id/id/eprint/108768

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