Vikurfjara Beach Project
Víkurfjara Beach Project
Katla Geopark and Víkurskóli elementary school, in collaboration with Katla Centre in Vik, started a research project called the Víkurfjara Beach Project on the 12th of January 2021. The project aims to study shoreline changes at Víkurfjara beach in front of the village of Vík in the coming years. The shoreline changes are monitored by measuring six beach profiles four times a year, the position of the beach ridge once a year, take sand samples from the beach for sieving and photograph the morphology of the beach during every measurement.
The Víkurfjara beach project received a grant from Sprotasjóður: The Icelandic innovation fund for schools in 2021. Katla Geopark and Víkurskóli elementary school would like to thank Sprotasjóður for their grant and Jóhann Guðlaugsson for lending the project his TopCon GPS device which is used for the measurements.
The aim of the measurements is to monitor and research the stability of the Víkurfjara beach that is protected by the two groynes, as well as providing a platform for students to learn and get experience in conducting scientific research. During the project, the students will take care of all measurement on the beach as well as take care of the data processing, grain size analysis of sand samples, and take aerial photographs with a drone. Students will therefore get a good foundation in research methodology, but such experience will hopefully be useful to them in the future. The project is also intended to increase the students' understanding of coastal environments, especially sandy beaches such as those at Vík, sea currents, tides, waves, and the impact that glacial outburst floods from Katla have on the beach.
The six profiles were set up at Víkurfjara beach when the project started (figure 1), two in the western part of Víkurfjara beach, three between the two groynes, and one east of the groynes. Students measure the profiles with a precise GPS device and a point is taken where the slope of the beach changes. With such measurements, the surface of the beach is measured (figure 2 and 3) at each profile, which is then used to calculate changes in the width and volume of the beach at each profile, which then tell whether the beach has been stable between measurements or not (tables 1-6, Figure 4).
All students at Víkurskóli elementary school participate in the study, but students in 5th-10th. class measure the profiles, together with taking photographs, samples and aerial photographs, while 1st-4th. class conducts independent research on the beach, including the sand and the wildlife that can be found there.
The results from the research project will be able to show the stability of the beach at Vík, how the beach adapts to changing conditions, how the beach recovers from storms and what the long-term development of the beach is in relation to erosion. The students will present their results below and they are updated after each measurement, and the photographs taken by the students during the measurements can be seen here.
Figure 1 shows the location of the six profiles at Víkurfjara beach that are measured by the students. Profiles 1 and 1.5 are in the western part of the beach, profiles 2, 3 and 4 are between the two groynes and profile 5 is east of the groynes.
Figure 2 shows the students' measurements on the beach. Each measurement is represented by different colored lines, and you can see the measurement month for each colour at the top of the figure. Students measure the surface of the beach and then the width and the volume can be calculated, but you can also see from the graphs if there is accretion or erosion on the beach and if the beach is getting shorter or not.
Figure 3 shows the last two measurements by the students at Víkurfjara beach. Each measurement is represented by different colored lines, and you can see the measurement month for each colour at the top of the figure.
To examine changes in the beach between measurements, the width of the beach at a height of 1 m is calculated together with the volume of the profile, and these results are compared with previous measurements. The results can be seen in the tables and graphs below. As you can see in the tables and the graphs, the profiles in the western part of Víkurfjara beach have been growing over the measurement period, the beach between the groynes started to decrease considerably but has been increasing in recent months, while the profile east of the groynes has been on a steady decline since measurements began but did however grow significantly between the last two measurements.
Tables 1-6 show the calculations of changes in width and volume on the beach at the six profiles.
Figure 4 shows the volume (red line) and beach width (blue line) of the profiles from tables 1-6, which show the calculations of changes in the width and the volume of the beach at the six profiles since the beginning of the measurements. The green line then shows the development of the volume of each profile, but if the line is rising it means that the volume is increasing since the first measurement, but if it is falling, the volume is decreasing.
The students also measure the position of the beach ridge once a year and this is done to check the stability of the beach ridge at Víkurfjara beach, to check if erosion is taking place or if the ridge is stable or even advancing.
The beach ridge has been measured twice so far and the measurements can be seen in pictures 5 and 6. As can be seen from the measurements, the beach comb in the western part of Víkurfjara beach, where profiles 1 and 1.5 are, has moved back slightly between measurements. The beach there has built up rapidly in recent years, since the first groyne was built, and the old beach ridge is now so far inland that it has become stable, and waves no longer reaches it during storms. A new beach ridge will eventually form closer to sea level, but currently the vegetation is still moving closer to the sea. The measurement in the western part of Víkurfjara beach is therefore actually a measurement of the vegetation line of the beach, but these measurements together with the measurements of the two profiles will give a good insight into how a new beach ridge gets formed. It is therefore the vegetation line that has receded, not the ridge itself, which was most likely caused by sandstorms during the previous winter. Since the second measurement was made in February 2022, the Soil Conservation Service of Iceland (SCSI) has sown lime grass seeds in front of the beach ridge, and therefore the students' measurements will in the future map the area where the lime grass was sown, and in the process show whether the reclamation has worked or not.
The situation of the beach ridge between the two groynes is different, as the beach ridge is an old erosion scarp at the beach and is only partially covered by vegetation. Between the two measurements, erosion has occurred to the east of profile 4 and between profiles 3 and 4, but it is not extensive. There has also been landslides and erosion on the western part, but a part of it is due to tourist traffic on the beach, especially around the footpath that leads from the car park in front of Icewear. It can also be seen that considerable erosion have occurred at the beach ridge at profile 4 since the aerial photograph was taken, which was in 2020. It is therefore clear that erosion can still occur there, and the students' measurements will monitor this in the future.
Figure 5 shows the students' measurements of the beach ridge in the western part of Víkurfjara beach. The ridge has been measured twice, in February 2021 (yellow line) and in February 2022 (purple line).