Evapotranspiration of Paddy Based on SEBAL Algorithm at El Nino Time : Gorontalo Regency
Ghinia Anastasia Muhtar1, Intan Purwandhi2, Heny Mariati3
1Universitas Muhammadiyah Gorontalo
2Badan Pusat Statistik Kabupaten Gorontalo
3Universitas Tamansiswa Padang
Abstract
El Nino climate is one of the issues related to water management in Indonesia, especially rice plants that only rely on rain water. Therefore, this research has conducted a study to measure water loss or evapotranspiration using the SEBAL algorithm. ET estimation methods like Surface Energy Balance Algorithm for Land (SEBAL) method can be used based on the satellite images. The results of the study showed net radiation flux (Rn) has a real interaction with Surface temperature (St), which increase in the value of Rn along with an increase in St. Next, the values of G, λ and H gradually decrease with decreasing Rn. Compared with H and G, the diurnal variation amplitude of λ is much greater. Overall the actual evapotranspiration value during El Nino climate is smaller than in normal climate. This indicates that there are a lot water in paddy field during normal years compared to El Nino years, although the value of St in El Nino years is higher than normal years.
Keywords: Evapotranspiration, Paddy, Sebal, Landsat 8 OLI
Topic: Environmentally Sustainable Agriculture