Preliminary Evaluation of Weather Radar Rainfall Estimation in Bandung City

Rainfall is one of the weather parameters with an essential role in many sectors, such as hydrological models, agriculture, disasters, tourism, environment, transportation, and others. Automatic Weather Stations (AWS) and Automatic Rain Gauges (ARG) are ground station equipment to measure weather parameters, including rainfall intensity. Rain gauges entail drawbacks for high spatial and temporal variability of rainfall, particularly at low equipment density level. Weather radars offer various advantages in representing weather phenomena, comprising estimating rainfall distribution in high temporal resolution and spatial resolution and presenting data in extensive observations. Reflectivity is a product of radar observation. It will be processed through Z-R Rosenfeld Tropical Relationship to obtain rainfall estimation in the site. Alas, weather radars show certain limitations, including beam blocking from closest surface, beam attenuation, radio frequency interferences, and cones of silence or unobserved areas close to the ground. This study evaluated the radar rainfall estimation compared to spatial and temporal rain gauges in Bandung. Radar image data can be optimized and useful in rainfall estimation, predominantly in several areas in Bandung City with no rain gauge. Evaluation indicators applied statistical analysis, namely correlation coefficient, root mean square, and mean absolute error. The results of the correlation coefficient value suggest a significant correlation of 0.9003, and the resulting RMSE and ME values were 4.55 mm/daily and 9.05 mm/daily. The effect of distance and radar limitations affected the quality of the data generated by radar.