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Wave dynamics contribute significantly to coastal hazards and were thus investigated at Vougot Beach by simulating both historical and projected future waves considering climate change impacts. The historical period included a major storm event. This period was projected to the future using three globally averaged sea level rise (SLR) scenarios for 2100, and combined SLR and wave climate scenarios for A1B, A2, and B1 emissions paths of the IPCC. The B1 wave climate predicts an increase in the occurrence of storm events. The simulated waves in all scenarios showed larger relative changes at the beach than in the nearshore area. The maximum increase of wave energy for the combined SLR and wave scenarios was 95%, while only 50% for the SLR-only scenarios. The effective bed shear stress from waves and currents showed different spatial variability than that of the wave height, emphasizing the importance of interactions between nearshore waves and currents. Increases in the effective bed shear stress (combined scenarios: up to 190%, and SLR-only scenarios: 35%) indicate that the changes in waves and currents will likely have significant impacts on the nearshore sediment transport. This work emphasizes that combined SLR and future wave climate scenarios need to be used to evaluate future changes in local hydrodynamics and their impacts. These results provide preliminary insights into potential future wave dynamics at Vougot Beach under different climate change scenarios. Further studies are necessary to generalize the results by investigating the wave dynamics during storm events with different hydrodynamical conditions and to evaluate potential changes in sediment transport and morphological evolution due to climate change.

Wave dynamics contribute significantly to coastal hazards and were thus investigated at Vougot Beach by simulating both historical and projected future waves considering climate change impacts. The historical period included a major storm event. This period was projected to the future using three globally averaged sea level rise (SLR) scenarios for 2100, and combined SLR and wave climate scenarios for A1B, A2, and B1 emissions paths of the IPCC. The B1 wave climate predicts an increase in the occurrence of storm events. The simulated waves in all scenarios showed larger relative changes at the beach than in the nearshore area. The maximum increase of wave energy for the combined SLR and wave scenarios was 95%, while only 50% for the SLR-only scenarios. The effective bed shear stress from waves and currents showed different spatial variability than that of the wave height, emphasizing the importance of interactions between nearshore waves and currents. Increases in the effective bed shear stress (combined scenarios: up to 190%, and SLR-only scenarios: 35%) indicate that the changes in waves and currents will likely have significant impacts on the nearshore sediment transport. This work emphasizes that combined SLR and future wave climate scenarios need to be used to evaluate future changes in local hydrodynamics and their impacts. These results provide preliminary insights into potential future wave dynamics at Vougot Beach under different climate change scenarios. Further studies are necessary to generalize the results by investigating the wave dynamics during storm events with different hydrodynamical conditions and to evaluate potential changes in sediment transport and morphological evolution due to climate change.

Seasonal airborne and ground-based observations of sand level changes were made along the coast of southern California from 2001 to 2008. Hourly, high alongshore spatial resolution wave estimates from a network of wave buoys and a spectral refraction wave model complement the sand level change data. Water returns from the ocean surface were removed from the airborne lidar elevation observations with a new method using tide and wave data, which was validated with concurrent in situ surveys. The resultant sand levels show high alongshore variability in seasonal shoreline position change along the 120-km survey region. Alongshore variability in wave energy, geologic factors, and sand grain size are hypothesized to control the alongshore variability of the seasonal shoreline change magnitude. Monthly or more frequent ground-based surveys at four selected focus sites show seasonal shoreline and bathymetry change, with winter shoreline erosion and offshore bar development, and summer shoreline accretion and the loss of the offshore bar. Analysis of surveys completed after a small beach nourishment at Torrey Pines Beach showed the presence of the nourishment through more than one full seasonal cycle. Observations from Torrey Pines Beach show the dependence of shoreline change on the initial shoreline position and the wave forcing. The observations motivated the development of an equilibrium shoreline change model, which accurately reproduces the observations with four free parameters. With at least two years of monthly surveys or multiple years of appropriately-timed biannual observations used to determine the free parameters, the model accurately predicts withheld observations and is applied at the additional survey sites. Ongoing work includes applying the model at additional locations and investigating the relationship between the tuned parameters and geologic factors

Seasonal airborne and ground-based observations of sand level changes were made along the coast of southern California from 2001 to 2008. Hourly, high alongshore spatial resolution wave estimates from a network of wave buoys and a spectral refraction wave model complement the sand level change data. Water returns from the ocean surface were removed from the airborne lidar elevation observations with a new method using tide and wave data, which was validated with concurrent in situ surveys. The resultant sand levels show high alongshore variability in seasonal shoreline position change along the 120-km survey region. Alongshore variability in wave energy, geologic factors, and sand grain size are hypothesized to control the alongshore variability of the seasonal shoreline change magnitude.Monthly or more frequent ground-based surveys at four selected focus sites show seasonal shoreline and bathymetry change, with winter shoreline erosion and offshore bar development, and summer shoreline accretion and the loss of the offshore bar. Analysis of surveys completed after a small beach nourishment at Torrey Pines Beach showed the presence of the nourishment through more than one full seasonal cycle.Observations from Torrey Pines Beach show the dependence of shoreline change on the initial shoreline position and the wave forcing. The observations motivated the development of an equilibrium shoreline change model, which accurately reproduces the observations with four free parameters. With at least two years of monthly surveys or multiple years of appropriately-timed biannual observations used to determine the free parameters, the model accurately predicts withheld observations and is applied at the additional survey sites. Ongoing work includes applying the model at additional locations and investigating the relationship between the tuned parameters and geologic factors.

Seasonal airborne and ground-based observations of sand level changes were made along the coast of southern California from 2001 to 2008. Hourly, high alongshore spatial resolution wave estimates from a network of wave buoys and a spectral refraction wave model complement the sand level change data. Water returns from the ocean surface were removed from the airborne lidar elevation observations with a new method using tide and wave data, which was validated with concurrent in situ surveys. The resultant sand levels show high alongshore variability in seasonal shoreline position change along the 120-km survey region. Alongshore variability in wave energy, geologic factors, and sand grain size are hypothesized to control the alongshore variability of the seasonal shoreline change magnitude.Monthly or more frequent ground-based surveys at four selected focus sites show seasonal shoreline and bathymetry change, with winter shoreline erosion and offshore bar development, and summer shoreline accretion and the loss of the offshore bar. Analysis of surveys completed after a small beach nourishment at Torrey Pines Beach showed the presence of the nourishment through more than one full seasonal cycle.Observations from Torrey Pines Beach show the dependence of shoreline change on the initial shoreline position and the wave forcing. The observations motivated the development of an equilibrium shoreline change model, which accurately reproduces the observations with four free parameters. With at least two years of monthly surveys or multiple years of appropriately-timed biannual observations used to determine the free parameters, the model accurately predicts withheld observations and is applied at the additional survey sites. Ongoing work includes applying the model at additional locations and investigating the relationship between the tuned parameters and geologic factors.

Seasonal airborne and ground-based observations of sand level changes were made along the coast of southern California from 2001 to 2008. Hourly, high alongshore spatial resolution wave estimates from a network of wave buoys and a spectral refraction wave model complement the sand level change data. Water returns from the ocean surface were removed from the airborne lidar elevation observations with a new method using tide and wave data, which was validated with concurrent in situ surveys. The resultant sand levels show high alongshore variability in seasonal shoreline position change along the 120-km survey region. Alongshore variability in wave energy, geologic factors, and sand grain size are hypothesized to control the alongshore variability of the seasonal shoreline change magnitude. Monthly or more frequent ground-based surveys at four selected focus sites show seasonal shoreline and bathymetry change, with winter shoreline erosion and offshore bar development, and summer shoreline accretion and the loss of the offshore bar. Analysis of surveys completed after a small beach nourishment at Torrey Pines Beach showed the presence of the nourishment through more than one full seasonal cycle. Observations from Torrey Pines Beach show the dependence of shoreline change on the initial shoreline position and the wave forcing. The observations motivated the development of an equilibrium shoreline change model, which accurately reproduces the observations with four free parameters. With at least two years of monthly surveys or multiple years of appropriately-timed biannual observations used to determine the free parameters, the model accurately predicts withheld observations and is applied at the additional survey sites. Ongoing work includes applying the model at additional locations and investigating the relationship between the tuned parameters and geologic factors