A systematic assessment of flooding potential in a semi-arid watershed using GRACE gravity estimates and large-scale hydrological modeling

Abstract

The emergence of the Gravity Recovery And Climate Experiment (GRACE) paved the way for remote tracking of hydrological water cycle components at large scales. With the main motivation of evaluating the feasibility of the coarse resolution GRACE data for small-scale analysis, the GRACE data and large-scale hydrological models were utilized in an integrated manner to monitor the variations of the flood potential index (FPI) over the Western Anatolian Basin (WAB). The results show an ascending trend for monthly and annual FPI over the WAB. The results also suggest that the monthly FPI in 2015, 2003, 2009, and 2016 was the highest, from which the highest potentiality of flood appertains to 2015/07 with an FPI of 0.92. The lowest and highest annual FPI is 0.26 (in 2007) and 0.76 (in 2015), respectively. The validation of the results indicates that variations of FPI coincide with that of the flood incidents, stream discharge, Standardized Precipitation Index (SPI), and the simulated flood risk. The findings accentuate the high feasibility of the GRACE JPL Mascons for better surveillance of floods over local scale areas.

Highlights

• The coarse resolution GRACE JPL mascon functions very well in tracing the spatio-temporal characteristics of flood incidents over local scales.

• There is an ascending trend in the variations of flood potential over the Western Anatolia Basin (WAB).

• The WAB has experienced its lowest and highest possibility of flooding in 2007 and 2015 with an average FPI of 0.26 and 0.76, respectively.

• The variations of the flood potential index (FPI) coincides with that of the reported flood incidents, stream discharge, Standardized Precipitation Index (SPI), and the simulated flood risk.

Keywords:

• Flood potential
• flood risk
• GRACE
• Noah
• remote sensing
• Western Anatolian Basin

Acknowledgments

We would like to offer our sincere gratitude to the Turkish State Hydraulic Works and the Turkish State Meteorological Service for providing our research with the in-situ observations of streamflow and precipitation respectively, without which this research could not be implemented.

Disclosure statement

The authors would like to state that there are no financial interests or connections that might raise the question of bias in the work reported or the conclusions, implications, or opinions stated.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Authors’ contribution

Behnam Khorrami (Conceptualization, Methodology, Data collection and analysis, Writing), Okan Fistikoglu (Conceptualization, Review), Orhan Gunduz (Methodology, Data collection, Review, and Editing)

Data availability statement

The data and codes that support the findings of this study are available upon a rational request from the corresponding author.

Sources of funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.