Evaluating the Efficiency of Global Databases in Estimating Water Balance Components in Data Shortage Conditions (Case Study: Tashk-Bakhtegan Basin)

Document Type : Research Paper


1 Department of Water Engineering and Management, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

2 Tarbiat Modares University



Global database and satellite products with high spatial and time-lapse power, can be seen as a suitable alternative source for conducting studies of water balance components in statistically deficient areas and areas with no uniform distribution of stations. Use of this data provided that it has sufficient accuracy, for Iran, which many of its parts, especially desert and mountainous areas, due to the low density of stations, the short statistical period of new stations always faces problems of accessing local and time information in the region. They will be, of great importance it is. The main goal of the research is to assess the global database and satellite products to estimate real rainfall, Evapotranspiration, and changes in water storage in the Tashk-Bakhtegan basin. Used GLDAS, PERSIANN - CDR, CHIRPS, NCEP database to assess the rainfall according to our objectives. For real Evapotranspiration, the real amounts of evaporation and absorption were first extracted based on the Balance Torrent White equation, and the results were evaluated by the GLDAS database, GLEAM. The GRACE satellite was used to estimate the changes in the region's water reserves and to assess it the GLDAS satellite was used to extract annual changes in groundwater. Results obtained showed that the PERSIANN - CDR database performed best and consistent with its observational data across all statistical indicators before and after the Bias correction. GLEAM also had the best statistical performance in estimating Evapotranspiration before and after correction with Balance Torrent White Equation data. Comparison of the observation levels of underground water with data extracted from GRACE and GLDAS satellites indicates the existence of a similar trend, and, based on the power of GRACE's low locality segregation and the low area studied, the results for groundwater changes and Ground water is acceptable. The results of the present study show data from the PERSIANN- CDR satellite for rain, GLEAM model for real evaporation and absorption and GRACE satellite for estimating ground water changes as a convenient tool for making early, quick and low - cost estimates on Water Balance Components It will be used.


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