Validation of Tropical Rainfall Measuring Mission (TRMM) Data in the Upper Kapuas River Basin

Abstract

Rainfall is a difficult parameter to measure, due to large spatial and temporal variations. Lack of data availability, data incompletely, less spreading of station, less observer, and manual data entry are other problems for rainfall predicting. To encourage these problems rainfall satellite can be used, because it has high temporal and spatial resolution, widely coverage, near real-time and fast accessibility. This research was conducted in the upper Kapuas River Basin, West Kalimantan, to determine how TRMM satellite-derived rainfall compares with ground-measured values and the possibility of using it to complement ground-measured rainfall. The statistical analyses and correction factor development for TRMM data are conducted to validate and correct the TRMM data on eleven sub basin in Kapuas River basin. Validation showed high correlation between TRMM and gauge data. Validation shows a high correlation and lowest RMSE between TRMM and gauge data in the sub basin adjacent to the gauge station (r= 0.76-0.8, RMSE 0,84-0,92). The results of the analysis also show that after correction, the corrected TRMM data errors were reduced for the eleven rainfall.