Estimation of crop water deficit through remote sensing in Central Luzon, Philippines

Estimation of crop water deficit continues to be challenging especially when attempting to evaluate it at large areas. The limitation of cloud free images availability can be overcome with the combination of high-spatial and temporal resolution images in the tropical climate. In this study, Landsat 7 & MODIS satellites Image on the same overpass date was selected on May 18, 2001 in the dry season 2001. Comparing positively the results of Modis, and Landsat 7 ETM+ sensors for water consumption studies at different scales In Irrigation system would enable better decision-making for located crop water requirement. The Surface Energy Balance Algorithm for Land (SEBAL) has been applied to Landsat 7 ETM+, and MODIS sensors for the estimation of crop water requirement In District I of the Upper Purnapanga River Integrated Irrigation System (UPRIIS) In Central Luzon of Philippines. The actual evapotranspiration was integrated for 24 hours on pixel-by-pixel basis from the Instantaneous evapotranpiration (ET). This paper shows a unique combination of derived ETa from Landsat and the MODIS images for water consumption studies In District 1. Volumes of water consumption and deficit were compared at different pixel sizes. The results were compared with the evapotranspiration calculations at two meteorological stations In District 1 of UPRIIS. The discussion provides the research orientation of the scale assessment of evaporation and further Implications In applied research for water management aided by satellite Images.