Evaluating precipitation estimates over Jazmurian Basin using satellite images and ground-based observations

In recent years, remote sensing technology has been considered as a useful tool to estimation of precipitation and its spatial-temporal variations. The current study aims to estimate the amount of annual precipitation in the Jazmurian basin using remote sensing and ground-based observed data. For this purpose, the mean annual precipitation of the study region for the period of 1998 to 2017 was calculated by Thiessen method. Besides, the CHIRPS, PERSIANN-CDR and TRMM satellite products for the same period, were processed using Google Earth Engine. The results showed that based on ground observed data, the mean annual precipitation (1998-2017) of the Jazmurian basin is approximately 124 mm. The corresponding values of TRMM, CHIRPS and PERSIANN-CDR annual precipitation products, were approximately 139, 99.5 and 154 respectively. The spatial pattern of precipitation revealed that the amount of precipitation decreased from the west to the east of the basin and the lowest precipitation values are observed in central and eastern regions of Jazmurian basin. In general, TRMM provided more reliable estimations (correlation coefficient = 0.88 and lowest RMSE), therefore it can be considered as an alternative for observed data especially in areas where weather stations are limited and sparse.