Comparison of GLDAS and Measurement Data for Precipitation Parameter in Gediz Basin, Turkey

Abstract

Datasets containing remote sensing methods and land surface model outputs are frequently used in the process of conducting hydrometeorological studies on a global scale. This study, it is aimed to compare the precipitation data of the Global Land Data Assimilation System (GLDAS), which is one of these data sets, with the station-based data for the Gediz Basin. The Gediz Basin, determined as the study area, is defined as semi-arid. For this reason, observing the precipitation parameter and investigating its spatial-temporal variability is very important for this basin. This study was carried out from 2014 to 2020. The temporal and spatial precipitation patterns of the study period were compared in general. In addition, it is aimed to quantitatively determine the success of GLDAS representing the precipitation parameter with three different performance metrics (R2, KGE and NSE). According to the results obtained, it has been observed that the precipitation parameter of GLDAS represents the temporal and spatial pattern and is consistent with the station-based data. In addition, this result is supported by performance metrics. Based on this, it is thought that the precipitation data in GLDAS is a suitable data set for hydrometeorological studies to be carried out in the Gediz Basin.