## 5 Conclusions  
Aerial photographs, Lidar data, and satellite images have been used to map changes in the shoreline locations along a prograding shingle shoreline at Dungeness from 1940 to 2019. Ground-penetrating radar (GPR) reveals the internal structure of the beach ridges and the thickness of shingle on this composite gravel beach. The beach ridges are underlain by seaward inclined reflections from beachface progrades, and the thickness of the shingle decreases from south north. By combining mapping of the planform areas of accretion with measurements of beach thickness, we have calculated volumes of sediment accumulation over the past 79 years (1940-2019). The width and the thickness of shingle decreases from south to north, which is the direction of longshore drift. Mapping of sediment accretion from beach ridges at Dungeness tend to confirm earlier observations and interpretations of the formation of Dungeness cuspate foreland made by [2]. We disagree over the accretion of beach ridges on the east facing shore to the north of the Ness where [2] considered that the longshore drift from southwest waves could be neglected. The northward decrease in the width and thickness of the beach ridges is testament to be continued but by reducing northward longshore drift along the eastern side of Dungeness. The northward movement of sediment along the coast, and resulting overlap of beach ridge accretion surfaces, and northward decrease in rates of accretion is best explained by northward longshore drift. While erosion downdrift from salients impacts the preservation of beach ridges, this does not exclude easterly storm waves as geographic agents in construction of beach ridges on the east side of Dungeness, but we suggest that the south-west waves continue to play a significant role in the sediment transport along this drift aligned shore. The preservation of different numbers of beach ridges along the coast within a known time period raises questions for the reconstruction of storm records from beach ridge sequences. Estimates of sediment accumulation using GPR profiles and freely available remote sensing data agree well with measurements of sediment accumulation from shoreline monitoring data from annual ground-based GPS surveys. There is a decrease in the rates of accretion between 1960 and 1990, which is a possible consequence of the beach recharge schemes put in place to protect the nuclear power station, but it is also worth noting that a decrease in storms during the 1960s could have had a similar effect by reducing sediment erosion on the southwest facing shore. It should be noted that since 1990, beach accretion on the east side of Dungeness, at Lydd on Sea and approaching Greatstone, has returned to values similar to those before the beach recharge scheme started, suggesting that while there might have been a short-term impact this has not persisted. We conclude that the beach recharge scheme used to protect the two nuclear power stations at Dungeness does not appear to have had a negative impact on the beach downdrift. A major limitation of this study is the granularity of the historic images, the periods between aerial surveys that prevents more detailed analysis of the rates, and timing of beach accretion.  
Project conceived by [PERSON] who supervised L.B. and M.I. M.I. and L.B. collected the GPR data and processed the Lidar data. [PERSON] wrote the manuscript. All authors have read and agreed to the published version of the manuscript.  
L.B. is funded by London NERC DTP grant NE/L002485/1, and MI was funded by C N Yang Scholars Program, NTU.  
Not applicable.  
GPR and topographic data is archived at the Birkbeck Data Repository BiRD [[https://doi.org/10.18743/DATA.00160](https://doi.org/10.18743/DATA.00160)]([https://doi.org/10.18743/DATA.00160](https://doi.org/10.18743/DATA.00160)) (accessed on 22 September 2021).  
We would like to thank the warden and landowners at Dungeness for permission to work there.  
The authors declare no conflict of interest.