ANALISIS PENGARUH LINTANG TERHADAP EVAPOTRANSPIRASI BERDASARKAN DATA KLIMATOLOGI DI PALU DAN SLEMAN - Agung Purwanto; Frandi Sibuan; David S.V.L Bangguna; Jhonson Andar Harianja (Prodi Sarjana Teknik Sipil, FT, Universitas Tarumanagara, 2026)
Indonesia is a tropical country located near the equator, receiving high solar radiation intensity throughout the year. This condition leads to variations in climatic elements among regions, which may influence the magnitude of evapotranspiration. This study aims to analyze the effect of distance from the equator on evapotranspiration values in Palu City (Central Sulawesi) and Sleman Regency (Special Region of Yogyakarta). The data used in this study consisted of secondary climatological data, including air temperature, relative humidity, wind speed, and solar radiation. Evapotranspiration was calculated using the Penman–Monteith, Linacre & Hobbs, Kohler & Parmele, Priestley & Taylor, Stewart & Rouse, and Camargo methods. Among these six empirical methods, the results obtained using the Priestley & Taylor (1972) method were the closest to the evaporation pan observations recorded at the BMKG stations in Palu and Sleman. The results indicate that during the periods of January–June and August–December, evapotranspiration values in Palu were generally higher than those in Sleman. This finding suggests that regions located closer to the equator tend to experience higher evapotranspiration rates. However, in July, evapotranspiration in Sleman was higher than in Palu. This condition occurred because rainfall in Palu was higher during July, resulting in lower air temperatures compared to Sleman. Abstrak Indonesia merupakan negara tropis yang terletak di sekitar garis khatulistiwa sehingga menerima intensitas radiasi matahari yang tinggi sepanjang tahun. Kondisi ini menyebabkan variasi unsur iklim antar wilayah yang berpotensi memengaruhi besarnya evapotranspirasi. Penelitian ini bertujuan untuk menganalisis pengaruh jarak dari garis khatulistiwa terhadap nilai evapotranspirasi di Kota Palu (Sulawesi Tengah) dan Kabupaten Sleman (Daerah Istimewa Yogyakarta). Data yang digunakan dalam penelitian yaitu data klimatologi sekunder meliputi suhu udara, kelembapan relatif, kecepatan angin, dan radiasi matahari, Perhitungan evapotranspirasi dilakukan menggunakan metode Penman–Monteith, Linacre & Hoobs, Kohler & Parmele, Priestley & Taylor, Stewart & Rouse, dan Camargo. Dari keenam metode empiris tersebut, hasil metode Priestley & Taylor (1972) lebih mendekati hasil panci penguapan stasiun BMKG Palu dan Sleman. Hasil penelitian menunjukkan bahwa pada periode Januari–Juni serta Agustus–Desember, nilai evapotranspirasi di Palu umumnya lebih tinggi dibandingkan Sleman. Hal ini mengindikasikan bahwa wilayah yang lebih dekat dengan garis khatulistiwa cenderung memiliki tingkat evapotranspirasi yang lebih besar. Tetap pada bulan Juli, nilai evapotranspirasi di Sleman lebih tinggi dibandingkan Palu, kondisi ini terjadi karena pada bulan Juli curah hujan di Palu lebih tinggi sehingga suhu udara menjadi lebih rendah dibandingkan Sleman.