Development of variogram models retrieved from PERSIANN family and TRMM 3B47 V. 7 satellite-derived datasets in Fars province

Mahmood Reza Shaghaghian ¹ ( Department of Civil Engineering, Faculty of Engineering, Shiraz branch, Islamic Azad University, Shiraz, Iran )
KEYVAN KHOJAND ² ( Department of Civil Engineering , Faculty of Engineering , Estahban Branch , Islamic Azad University , Estahban , Iran )
ZAHRA GHADAMPOUR ³ ( Department of Civil Engineering, Faculty of Engineering, Estahban branch, Islamic Azad University, Estahban, Iran )
Tooraj Sabzevari ⁴ ( Department of Civil Engineering, Faculty of Engineering, Esathban Branch, Islamic azad University, Estahban, Iran )

Submited date : 2023-05-01 Accepted date : 2024-02-14

Keywords: variogram, satellite-derived datasets, Gaussian model, trend removal,

Abstract :

Precipitation data is an essential component of hydrological models, particularly spatial models that require knowledge of the rainfall's spatial distribution. However, obtaining ground-based observations in various regions can be costly and challenging. As a result, satellite-derived datasets are becoming increasingly useful. In this study, four satellite-derived datasets (PERSIANN, PERSIANN-CDR, PERSIANN -CCS, and TRMM 3B43 V.7) were compared to determine the average annual precipitation variogram in Fars Province. Ground-based observations from 23 stations in the area were utilized to assess the datasets. It was noted that there were inconsistencies between the satellite-derived and ground-based datasets, and all satellite-derived datasets were non-stationary and anisotropic. To address these issues, linear or quadratic curves were removed from the initial satellite-derived datasets. After this trend removal, the datasets prepared from the PERSIANN -CCS and TRMM 3B43 V.7 products were isotropic and sufficiently stationary. Finally, the Gaussian model was used to express the variogram of the selected datasets.