Eskers – important natural resources and conflicting societal interests

Please focus on the esker closest to your geographical location. If there are no esker nearby, you can choose to examine the Badelundaåsen outside Västerås as an example. Badelundaåsen is a prominent feature in the landscape, running from the Nyköping area in the south to Siljan in the north.

There are many ancient monuments in the vicinity of the ridge, particularly around the Badelunda parish in Västerås. The area surrounding Badelundaåsen is an agricultural landscape, typical of the Mälardalen region, characterized by a mild climate.

Part 1 - Knowledge acquisition

In this section, the student will learn what an esker is, how it is formed, its composition, characteristics, and the hydrological cycle.

Find out:

• What is an esker?
• How are eskers formed?
• What is it composed of?
• What are its characteristics?
• What is the hydrological cycle?

Source material:

• About glaciofluvial sediments - Swedish Geological Survey (SGU) (in Swedish, new window)
• “Kunskapsbanken” - Swedish Meteorological and Hydrological Institute (SMHI) (in Swedish, new window)

Part 2 - Examine and describe the landscape

Here, the student should describe the landscape on and around the esker. In the map tool, you can find contour lines, soil type map, watercourses and lakes, vegetation map, land use, settlements, buildings, road network, archaeological sites, orthophoto, wells, and quarries.

Source material:

• Water Protection Areas - Geological Survey of Sweden (in Swedish, new window)
• Well Archive - Geological Survey of Sweden (in Swedish, new window)

Part 3 - Analyze and explain the landscape

Here, the student should analyze and explain why the terrain appears the way it does. The questions will provide guidance for the analysis.

• Where in the terrain do you find different soil types?
• What does the glacial outwash sediment consist of?
• If there is post-glacial clay in the area, when was it deposited?
• Do you find any correlations between vegetation and soil types?
• Are there any traces of human activity in the area? (Historical and contemporary)
• Where are the gravel quarries located? Why there?
• Why is the area around the esker characterized by agricultural landscape?
• Where are the water protection areas located? Where are the wells?
• Measure the area of any chosen water protection zone and estimate the area of a gravel quarry.

Tip:

Use the map to identify the gravel quarries, and then refer to the orthophoto to measure. To see the gravel quarries on the map, you need to zoom in. The term "grustäkt" (gravel quarry) is printed on the map, and the quarry's area is delineated by a line with small inward-pointing dashes.

Part 4 Analysis and discussion

Here, the student should analyze and discuss the measures needed to ensure a good water supply for drinking purposes. The student should also analyze and discuss alternative materials that can be used for construction and infrastructure instead of natural gravel.

• What measures are taken to secure a good water supply for drinking purposes?
• Are there any alternative materials that can be used for construction and infrastructure instead of natural gravel?

Tip:

To expand the task, you can ask the student to investigate other activities on or near the esker and how these activities can impact the esker.

Reference material:

• Using Crushed Rock - Geological Survey of Sweden (in, Swedish, new window)
• Water Protection Areas - Swedish Agency for Marine and Water Management (in Swedish, new window)