Deformation analysis of embankment dam Using field survey and multisensor InSAR time-series: A case study of Mosul Dam, Iraq

Abstract

Effective water resource management is crucial in Iraq’s arid climate, particularly concerning the Tigris and Euphrates rivers. The Mosul Dam, one of the country’s largest and most important infrastructures, plays a vital role in water supply and flood control. This study investigates structural displacement in Mosul Dam using three data sources: (1) field surveys with conventional instruments, and (2) synthetic aperture radar (SAR) images from Sentinel-1 and (3) ALOS-2 PALSAR-2 SAR images. The SAR data were processed using the SAR interferometric (InSAR) Small Baseline Subset (SBAS) technique. Analysis reveals that the central section of the dam experiences the most significant subsidence, whereas the lateral sections show relatively minor deformation. Field survey data from November 2013 to May 2024 indicate an average subsidence velocity of 2.82 mm/year, with a cumulative rate of 28.94 mm and a maximum recorded subsidence of 97.45 mm. SBAS analysis of Sentinel-1 data (November 2015–April 2024) shows an average subsidence velocity of 2.31 mm/year, with cumulative and maximum subsidence values of 15.52 mm and 74.40 mm, respectively. Similarly, SBAS analysis of ALOS-2 data (November 2014–March 2024) indicates an average subsidence velocity of 2.98 mm/year, with a cumulative rate of 14.37 mm and a maximum of 51.70 mm. Despite some variation in values among the datasets, the annual subsidence rates are closely aligned. All analyses consistently highlight two key findings: (1) the central section of the dam is most prone to subsidence, and (2) there is a distinct difference in displacement patterns (uplift and subsidence) between the central and lateral sections. These insights are critical for understanding the dam’s structural behavior and informing future management strategies to ensure its safety and functionality.

Keywords

• ALOS-2 PALSAR-2
• InSAR
• Sentinel-1
• Subsidence
• SBAS
• Field surveys
• Mosul Dam

References

1. Al-Ansari, N. (2013). Management of water resources in Iraq: Perspectives and prognoses. Engineering, 5(8), 667–68. https://doi.org/10.4236/eng.2013.58080
2. Al-Ansari, N., & Adamo, N. (2016). Mosul Dam full story: Safety evaluations of Mosul Dam. Journal of Earth Sciences and Geotechnical Engineering, 6(3), 185-212.
3. Al-Ansari, N., Adamo, N., Al-Hamdani, M., Sahar, K., Al-Naemi, R. (2021). Mosul Dam problem and stability. Engineering, 13(3), 105-124. https://doi.org/10.4236/eng.2021.133009
4. Al-Ansari, N., Adamo, N., Knutsson, S., Laue, J., & Sissakian, V. (2020). Mosul Dam: Is it the most dangerous dam in the world? Geotechnical and Geological Engineering, 38(3), 5179–5199. https://doi.org/10.1007/s10706-020-01355-w
5. ASDO. (2023). Association of State Dam Safety, Dams 101. Retrieved May 4, 2025, from https://damsafety.org/dams101
6. Barone, A., Fedi, M., Pepe, A., Mastro, P., Tizzani, P., & Castaldo R. (2025). Inferring 3D displacement time series through InSAR measurements and potential field theory in volcanic areas. Scientific Reports, 15, 4719. https://doi.org/10.1038/s41598-025-88006-3
7. Berardino, P., Fornaro, G., Lanari, R., & Sansosti, E. (2002) A new algorithm for surface deformation monitoring based on small baseline differential SAR interferograms. IEEE Transactions on Geoscience and Remote Sensing, 40(11), 2375–2383. https://doi.org/10.1109/TGRS.2002.803792
8. Bowen, S. (2007). Office of the special inspector general for Iraq reconstruction. Relief and reconstruction funded work at Mosul dam Mosul, Iraq. Retrieved May 4, 2025, from http://cybercemetery.unt.edu/archive/sigir/20131001121159/http:/www.sigir.mil/files/assessments/PA-07-105.pdf

9. Brunson, B., Hu, B., & Wang, J. (2020). Synthetic aperture radar phase unwrapping using region-growing with polynomial-based phase prediction. Geomatica, 74(4), 196-219. https://doi.org/10.1139/geomat-2020-0013
10. Cigna, F., & Tapete, D. (2021). Cigna, F., & Tapete, D. (2021). Present-day land subsidence rates, surface faulting hazard and risk in Mexico City with 2014–2020 Sentinel-1 IW InSAR. Remote Sensing of Environment, 253, 112161. https://doi.org/10.1016/j.rse.2020.112161
11. Emadali, L., Motagh, M., & Haghighi, M.H. (2017). Characterizing post-construction settlement of the Masjed-Soleyman embankment dam, Southwest Iran, using TerraSAR-X SpotLight radar imagery. Engineering Structures, 143, 261–273. https://doi.org/10.1016/j.engstruct.2017.04.009
12. Ferretti, A. Prati, C. & Rocca, F. (2000). Permanent scatterers in SAR interferometry. IEEE Trans, Geosci. Remote Sensing, 39(1), 8–20. https://doi.org/10.1109/36.898661
13. Gabriel, A., Goldstein, R., & Zebker, H. (1989). Mapping small elevation changes over large areas: Differential Radar interferometry. Journal of geophysical Research, 94(7), 9183–9191. https://doi.org/10.1029/JB094iB07p09183
14. Gama, F., Mura, J., Paradella, W., & de Oliveira, C. (2019). Advanced DInSAR analysis on dam stability monitoring: A case study in the Germano mining complex (Mariana, Brazil) with SBAS and PSI techniques. Remote Sensing Applications: Society and Environment, 16, 100267. https://doi.org/10.1016/j.rsase.2019.100267
15. Gheorghe, M., & Arma¸ S. I. (2016). Comparison of multi-temporal differential interferometry techniques applied to the measurement of Bucharest city subsidence. Procedia Environ, Sci, 32, 221–229. https://doi.org/10.1016/j.proenv.2016.03.027
16. Gracon LLC. (2023). Advantages of dams, benefits & importance of dam construction. Retrieved May 4, 2025, from https://graconllc.com/advantages-of-dams
17. Karimzadeh, S., Zulfikar, A. C., & Matsuoka, M. (2024). Time series analysis of L-band PALSAR-2 images in Istanbul and Kocaeli, Turkey. Big Earth Data, 8(3), 467-493. https://doi.org/10.1080/20964471.2024.2320466
18. Khafaji, K., & Ben Hamed, B. (2025). Improving the prediction of evaporation variable in Mosul Dam using ARIMA model and time series analysis. Fusion: Practice and Applications (FPA), 17(02), 342-355.
19. Lanari, R., Casu, F., Manzo, M., Zwni, G., Berardino, P., Manunta, M., & Pepe, A. (2007). An overview of the small baseline subset algorithm: a DInSAR technique for surface deformation analysis. Pure and applied geophysics, 164(4), 637–661. https://doi.org/10.1007/978-3-7643-8417-3_2
20. Li, W., Wu, Y., Gao, X., Wang, W., Yang, Z., & Liu, H. (2023). The distribution pattern of ground movement and co-seismic landslides: A case study of the 5 September 2022 Luding earthquake, China. Journal of Geophysical Research: Earth Surface, 129(5). https://doi.org/10.1029/2023JF007534
21. Martire, D., Iglesias, R., Monells, D., Centolanza, G., Sica, S., Ramondini, M., Pagano, L., Mallorquí, J., & Calcaterra, D. (2014). Comparison between differential SAR interferometry and ground measurements data in the displacement monitoring of the earth-dam of Conza della Campania (Italy). Remote sensing of environment, 148, 58–69. https://doi.org/10.1016/j.rse.2014.03.014
22. Mazzanti, P., Perissin, D., & Rocca, A. (2015). Structural health monitoring of dams by advanced satellite SAR interferometry: investigation of past processes and future monitoring perspectives. Proceedings Book of 7th International Conference on Structural Health Monitoring of Intelligent Infrastructure, Torino, Italy.
23. Milillo, P., Bürgmann, R., Lundgren, P., Salzer, J., Perissin, D., Fielding, E., Biondi, F., & Milillo, G. (2016). Space geodetic monitoring of engineered structures: The ongoing destabilization of the Mosul Dam, Iraq. Scientific Reports, 6, 37408. https://doi.org/10.1038/srep37408
24. Milillo, P., Perissin, D., Salzer, J., Lundgren, P., Lacava, G., Milillo, G., & Serio, C. (2016). Monitoring dam structural health from space: Insights from novelInSAR techniques and multi-parametric modeling applied to the Pertusillo dam Basilicata, Italy. International Journal of Applied Earth Observation and Geoinformation, 52, 221–229. https://doi.org/10.1016/j.jag.2016.06.013
25. Othman, A., Al-Maamar, A., Al-Manmi, D., Liesenberg, V., Hasan, S., Al-Saady, Y., Shihab, A., & Khwedim, K. (2019). Application of DInSAR-PSI technology for deformation monitoring of the Mosul Dam, Iraq. Remote Sensing, 11(22), 2632. https://doi.org/10.3390/rs11222632
26. Roque, D., Perissin, D., Falcão, A. P., Fonseca, A. M., Henriques, M. J., & Franco, J. (2015). Dams regional safety warning using time-series InSAR techniques. Proceedings Book of Second International Dam World Conference, Lisbon, Portugal, 21–24.
27. Rosenqvist, A., Shimada, M., Ito, N.,&Watanabe, M. (2007). ALOS PALSAR: A pathfinder mission for global-scale monitoring of the environment. IEEE Transactions on Geoscience and Remote Sensing, 45(11), 3307–3316. https://doi.org/10.1109/TGRS.2007.901027
28. Sica, S., & Pagano, L. (2009). Performance-based analysis of earth dams: Procedures and application to a sample case. Soils and Foundations, 49(6), 921–940. https://doi.org/10.3208/sandf.49.921
29. Tomás, R., Cano, M., Garcia-Barba, J., Vicente, F., Herrera, G., Lopez-Sanchez, J. M., & Mallorquí J. J. (2013). Monitoring an earthfill dam using differential SARinterferometry: La Pedrera Dam, Alicante, Spain. Engineering Geology, 157, 21–32. https://doi.org/10.1016/j.enggeo.2013.01.022
30. Wang, P., Xing, C., Pan, X., Zhou, X., & Shi, B. (2021). Microdeformation monitoring by permanent scatterer GB-SAR interferometry based on image subset series with short temporal baselines: The Geheyan Dam case study. Measurement, 184, 109944. https://doi.org/10.1016/j.measurement.2021.109944
31. Wang, T., Perissin, D., Rocca, F., & Liao, M. S. (2011). Three Gorges Dam stability monitoring with time-series InSAR image analysis. Science China Earth Sciences, 54(5), 720-732. https://doi.org/10.1007/s11430-010-4101-1
32. Yang, S., Zhang. J., Fu, L., Chen, C., Liu, Z., & Zhang W. (2023). Landslide detection using synergistic ALOS/PALSAR-2 and Sentinel-1A data in the Qinling-Daba Mountains. Applied Sciences, 13(21), 12080. https://doi.org/10.3390/app132112080
33. Zhou, W., Li, S., Zhou, Z., & Chang, X. (2016). Remote sensing of deformation of a high concrete-faced rockfill dam using InSAR: A study of the Shuibuya dam, China. Remote sensing, 8(3), 255. ; https://doi.org/10.3390/rs8030255