Beach profiling

The link below will be helpful as reference for this weeks writing prompt.

You'll be explaining the process of beach profiling in writing.

http://www.unesco.org/csi/pub/papers3/sande18.htm


Beach Profiling Method Summary
Beach profiling is a simple survey technique used to measure the contour of a beach. Very basic equipment, made from two 1.5 meter rods connected by a 3 meter rope, is used to create a line-of-sight with the horizon. The difference in elevation between the two poles defines the topographic change on that segment of the beach. The number resulting from this change is recorded as a single data point. These data points are recorded at regular intervals down the beach, from the frontal dune (or seawall) to the low water mark. When these data points are connected, they create a graphic depiction of the contour of the beach or the beach profile. A limitation of this method is its dependence on the visibility of the horizon. If clouds, fog, haze or rain obscure the horizon, then profiling should not be conducted that day and should be rescheduled. Single-use cameras or digital cameras are also used to photograph the beach at a few established points every month. Long-term beach monitoring data is the first step to understanding complex beach processes. This information, combined with ocean current and wave data, helps scientists to better understand how fast and why our beaches are changing.

Step by Step Instructions for the Emery Method of Beach Profiling Overview

Set a metal stake or pin in the ground as a control point for each profile line. The same control point is reused for all profiling and is the starting point of all measurements. A second pin or in some cases object (such as a utility pole, tree, chimney, etc.) is used also. These two reference points define a line to follow to measure a beach profile. At these control points, it often helps to place a temporary marker post that rises up from the dune or above a seawall to maintain a line-of-sight down on the beach.

1. Begin Notes. Fill in the top part of the log sheet. Include names of people in the team profiling that day, the date, time, profile name and number, beach location, etc.

2. Record Stake Height. Measure the height of the ground in relation to the top of the control point with the numbers (scale) up. If the ground is below the top of the control point, the rod will be held upside down, and the vertical number recorded will be negative. The person holding this rod should stand off the profile line for the next step.

3. Set Rod 1.Stand the end of one profile rod (Rod 1) on the ground next to the control point with the numbers (scale) up. The person holding this rod should stand off the profile line for the next step. 13

4. Set Rod 2. The second person takes Rod 2 toward the ocean. Looking back toward land and Rod 1, this lead person places Rod 2 (with scale up) on the profile line using the control points as a guide. Pick a horizontal distance of a meter (or other suitable distance if obstacles are in the way) as a spacing between the two poles. Use a graduated rope to do this and be careful to hold both poles straight up and down while setting Rod 2 in place.

5. Measure and Record. From the landward pole, the first person sights the horizon and the top of the lower of the two rods. This line-of-sight will intersect part way up the other rod. Read the elevation number marked on the other rod that is in line with the pole top and the horizon. Keep both poles vertical when reading! Note that sometimes the reading will come from Rod 1 and sometimes from Rod 2. This is because the ground may slope down or up and may change which pole is higher at different places on the beach profile line. When the ground slopes down toward the ocean, the forward rod (Rod 1) will be lower, and a negative [-] number is assigned to the vertical reading off of Rod 1. when the ground slopes up looking toward the ocean, the forward rod will be higher, and a positive [+] number is assigned to the reading. In this case, the number is read off the forward rod (Rod 2). So moving forward on the profile, uphill is [+] and downhill is [-]. Always use either a + or – before the number. It takes careful attention to get this right on each measurement. A single error will make the rest of the data plot incorrectly on a graph. Record the elevation change and horizontal distance between poles on the log sheet. Also note any features at the forward rod (such as edge of dune, slope change, water line, etc.) in the Notes column on the log sheet.

6. Move Ahead. After the notes are taken, move Rod 1 to the same “footprint” occupied by Rod 2. Take care to walk next to the profile line, not on top of it. The person at Rod 2 should wait for Rod 1 to come up alongside Rode 2 in order to be certain of getting the position correct. After Rod 1 is in the place of Rod 2, the forward rod can be moved ahead another one to three meters and placed on the ground in line with Rod 1 and the original control point(s). The job of the lead person is to be sure each forward move stays on the line. Rod 2 must be set down on the ground keeping the rope level.

7. Repeat Steps 6 and 7. Measure, Record, & Move. Continue to move ahead, repeat these steps all the way to the water. As you go, everyone on the team should look ahead for features to stop on and measure. If some feature, perhaps the edge of the dune, does not occur at a horizontal interval of one meter, then make the horizontal distance smaller. For example, if the dune edge is only 0.6 m from the last measurement, move the forward pole ahead only that far. On the next measurement move ahead only 0.4 (or 1.4) m in order to get back on a spacing of 1 m intervals. Keeping a set interval in whole meters will help with data analysis later. 14

8. Stop at the Water. Make a measurement that includes the water line. In the notes column of the log sheet abbreviate it W.L. and record the TIME it was measured. Because the height of the tide is changing, the time of the reading is important. Estimate the place on the beach where the water level would be without the waves, the still water level. There is no need to measure how far up the beach the swash is going at the time of the measurement.

9. Continue On (Optional). The process can be continued into the water if teams want to. This is optional and not necessary. In cold water there is a risk of hypothermia. In rough seas there is a risk of getting hit by breaking waves. Do not take chances. Always keep your personal safety and that of your team members in mind. A few extra points on a graph are not work the risk of personal injury.

10.Final Reading. At the last measurement, record the time finished in the Notes column on the log sheet. 11.Photograph the Beach. Refer to the Photo Instructions for your beach found in the following section. 12.Pack Up. Gather up all the gear, including any posts back at the control points, notes, and field gear. The profile is done!

The original reference on Emery beach profiling is: Emery, K.O., 1961, A simple method of measuring beach profiles: Limnology and Oceanography, v. 6, p. 90-93. Source: Maine Geological Survey, Department of Conservation, 22 State House Station, Augusta, ME 04333-0022