Worksheet Natural Resource Management c02-01 - Teacher Instructions

Building a Dam

Environmental effects to the building of a hydroelectric dam

Subjects:

Geography, Agriculture, Environmental Studies

Objectives:

• General skills: Identification of environmental repercussions to the creation of a hydroelectric dam

Materials:

• SEOS webpages that deal with water resource management.

Time needed:

• 1/2 school lesson during which the students will voice potential environmental effects of the presence of the dam.
  

Procedure:

• hand out the student worksheet to the students
• ask them to familiarise themselves with the area.
• have the students express potential impacts of the presence of the dam. Offer them hints such as atmospheric humidity and river water temperature, to urge them forward when they appear to have run out of ideas.
• The main impacts to the environment are:
• The presence of a large water body before the dam has increased atmospheric humidity. Rainfall is a bit more frequent and in he summer, high temperatures are more uncomfortable.
• The water that comes out of the dam is coming from the lower levels of the withheld water, and has a lower temperature than the surface water. This water is too cold for the irrigation of cotton seedlings and during the first years after the dam was used, many crops failed because the seedlings couldn't tolerate the low water temperatures.
• The cold water that finds its way to the north-east Aegean Sea is lowering the overall temperature. As a result, fish that were once living in the area have migrated, making it difficult for the local fishermen to catch enough fish.
• Because the temperature of the water near the delta is lowered, the local currents have changed. Now the previously safe nearby sandy coast is getting erroded very quickly, threatening the establishments that were built near the coast.