Analyzing Beach Profile Data

A beach profile measures the shape and relative amount of sand on the beach. In this section, we will describe generic “average” profiles that are representative for 2 different time periods (2001 to 2004 and 2004 to present). Sand level averages from both periods will be compared to the original sand height before sand was dumped on the beach.

As a note, point 1 (far left) is where the sea cliff meets the beach and is the most critical area for preventing cliff erosion. High sand heights = less cliff erosion!

Data from 2001 to 2004.

Above Figure #2a: Generalized Beach Profile Plot From 2001 to 2004.

This figure shows a representative presentation of data, which has been acquired at the Grandview Beach station from 2001 to 2004. Look at the heights nearest the cliff (farthest left) this is where the beach meets the cliff.

Important note: Both winter and summer data are well above the 2001 original sand heights! How much? Look at the data where the cliff meets the beach (far left) and read the vertical scale (in centimeters). These data show that near the cliff it is about 100 cm higher in the summer and 50 cm in the winter when compared with the original sand height (before dumping).

Data from 2004 to Present

Above Figure #2b: Generalized Beach Profile Plot from 2004 to present.

This figure shows a representative presentation of data, which has been acquired at the Grandview Beach station from 2004 to present. Look at the heights nearest the cliff (farthest left) this is where the beach meets the cliff.

Important note: Winter data is a little lower and summer data is a little higher than the 2001 original sand heights! The average sand height is about 20 cm above in the summer and 20 cm below in the winter compared to the original sand height (before dumping). Really it is about the same overall as before dumping.

Discussion

From 2004 to 2005 we have had a moderate El Nino condition with larger surf and higher than normal tides. Lots of other strange things have happened like large squid (1 meter or so) beaching themselves all over San Diego and 2-3 times the normal rainfall. Think about how El Nino conditions might affect the beach profile data?

Critical Thinking

1) How has the beach nourishment program been a success up to 2004? There is more information in the beach nourishment section on this timeframe.

2) How about 2004 to present? What processes occurred (with the El Nino) that would remove sand from the beach? Where did the sand go? There is some interesting information in the beach nourishment section on this timeframe.