region. This analysis revealed that the beach profiles in the hot-spot region were 
near to equilibrium condition and should not adjust further by cross-shore 
sediment transport processes. However, the more recently constructed beach 
profiles to the north have profile shapes significantly steeper than the 
equilibrium profile and will adjust in the cross-shore sense, resulting in recession 
of the shoreline (neglecting any additional gains or losses because of longshore 
sediment transport processes). 
Beach-fill end losses were established as a major contributor to the 
development of the Monmouth Beach hot spot through both analytical and 
idealized numerical evaluations. An analytical procedure to estimate the end 
losses from the beach fill protruding seaward of the adjacent fills and shoreline 
indicates that more than 50 percent of the placed volume could be expected to be 
lost from the region associated with beach-fill end losses. This estimate is 
greater than the approximately 40 percent of material actually lost, but neglects 
the presence of the two groins at the boundaries that serve to retard longshore 
sediment transport. The idealized numerical model study reasonably represents 
the measured losses and indicates that mitigative action in the form of groin 
extensions may be effective in reducing the losses from the hot-spot region. An 
estimated increase in beach-fill retention of 10-20 percent was estimated using 
the idealized model configuration, but for implementation of such a plan, 
detailed investigation is recommended. 
Evaluation of the planform evolution of the beach-fill project in the vicinity 
of the hot spot supports the findings of the beach-fill end-loss analysis. The 
visualization of measured beach profile data in a three-dimensional model 
reveals that material lost from the hot-spot region was gained in the sediment- 
starved profiles to the north. Analysis of the evolution of specific offshore 
contours reveals that the seaward protrusion of the beach fill in the hot-spot 
region adjusted to the general shape and orientation of offshore contours. 
The combined theoretical beach-fill end-loss computations and supporting 
bathymetric data convincingly point to beach-fill end losses as the primary factor 
causing the hot spot at Monmouth Beach. In addition, the offshore bathymetric 
contours may cause an increase in northerly sediment transport within the hot 
spot, further contributing to the longshore sediment losses. In efforts to maintain 
a protective beach in the hot-spot region to protect inland structures, this study 
suggests the modification of existing groins as a conceptual mitigative action to 
protect the 100-ft design berm. A detailed analysis of the impacts of groin 
modifications is recommended. 
Chapter 6 Conclusions 
47 
