Evaluating the Performance of PERSIANN and PERSIANN-CDR Satellite Products in Precipitation Estimation in Semi-Arid Region of Zagros

Rainfall is one of the most important environmental factors affecting the density and canopy cover percentage of plant species, erosion, and natural hazard status and its measurement is important for achieving appropriate water management. Satellite products have been introduced as an alternative method for ground-based measurements due to inaccessibility of some areas such as arid, semi-arid and mountainous areas and lack of temporal and spatial rainfall data. This study aimed to investigate the efficiency of PERSIANN and PERSIANN-CDR satellite products to measure monthly and annual rainfall in Chaharmahal and Bakhtiari province in time span of 2010 and 2016, using correlation coefficient, root means square error and relative bias. Results showed that PERSIANN-CDR yielded the highest correlation coefficient, lowest RMSE and lowest relative bias in both monthly and annual scales. Estimations of rainfall by both PERSIANN and PERSIANN-CDR products were more accurate in monthly scale compared to annual scale. The correlation coefficient of PERSIANN monthly and annual rainfall respectively were 0.833 and 0.465. These correlations for PERSIANN-CDR were 0.877 and 0.641, and statistically significant for monthly and annual rainfall data, respectively. Due to limited numbers of rainfall gauges and inappropriate distribution and their importance in watershed runoff studies, drought and vegetation studies, and using satellite rainfall products with high spatial and temporal coverage can be considered as a suitable data source in climate studies, especially in arid and semi-arid regions of Iran.