Computing the hourly co-efficient for downscaling the satellite precipitation data in mountainous tropical catchment

Abstract

This study compute the co-efficient to downscale the satellite precipitation data at hourly scale in the mountainous tropical catchment. Mountainous tropical catchments which played a vital role in securing primary resources for the reservoirs and sustaining agriculture on the downstream require consistent and effective monitoring. Using satellite precipitation data as an alternative was novel however, it was constraint by the conflict of spatial resolution and size of the sub-catchments. At present, even the satellite precipitation data at the most advanced of 0.1° was having limitation to represent the local rainfall variation especially in humid tropics in Southeast Asia. By far, most of the downscaling approach were limited to monthly rainfall downscaling at larger temporal scale. As the rainfall was temporally very dynamics which varied at hourly scale, it is crucial to made the high resolution of satellite precipitation available at this scale. In order to solve that gap, we initiate the downscaling procedures by incorporating the orographic factors and wind intensity and direction with hourly scale at 200 meter resolution. The satellite precipitation data from Global Precipitation Mission (GPM) is used as sample. The output of this study would be useful to produce high resolution satellite precipitation in the mountainous humid tropics; critical inputs for high spatial and temporal hydrologic applications on the sub-catchments of the mountainous watershed.