Climate Variability over a Tropical Perennial Cropland of Gubawan Watershed Using Remotely Sense Data

Sensible heat (Qs), latent heat (QL), and ground heat (Qg) flux energy partitioning are essential to determine the development of boundary layer. The study purposely to identify the seasonal and inter-annual variation of some climatic parameters and factors that affect the changed in Bowen ratio (β) on the perennial cropland of the Gubawan watershed. Remote sensing data sets for 10 -years (2009-2018) used and downloaded using the google earth engine. During the period it was observed the ranged values of sensible heat flux (Qs) (92.2 - 148.8 KW/m2 ), latent heat flux (QL) (244.3-340.4 KW/m2 ), ground heat flux (Qg) (0.19-1.31 KW/m2 ), rainfall (1112-2402 mm), and soil moisture content (30.0-34.8 kg/m2 ). The Bowen ratio β computed by getting the ratio of sensible heat and latent heat fluxes, has values ranged from 0.28 to 0.67 with a mean value of 0.4. The rainfall was significantly related to the Bowen ratio β during the wet season (March -July) and fewer rainfall months. Moreover, the Bowen ratio has positive linear relationships with sensible and ground heat fluxes with R2 values of 0.8735 and 0.2224, while latent heat (R2 = 0.4713) and soil moisture content (R2 = 0.7948) has inverse relationships. Therefore, there were clear indications of seasonal and inter-annual climate and Bowen ratio variability based on considered climate variables