Bhutan, the Last Shangri-La: Water Wheel: The Renewing and Cyclical Nature of Water Forces in the Kingdom
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By the end of this activity, students will:
1) Create a cloud in a bottle.
2) Be able to describe the conditions necessary for cloud formation at the tops of mountains.
3) Be able to describe why one side of a mountain range has higher rainfall than the other.
4) Understand the reason for the drenching monsoons on the Bhutan side of the Himalayan
5) Be able to describe the effect of the pounding of water on rocks as they move to the sea.
National Standards Science
1) Knows that good scientific explanations are based on evidence (observations) and scientific knowledge.
2) Establishes relationships based on evidence and logical argument (e.g., provides causes for effects)
3) Knows how land forms are created through a combination of constructive and destructive forces (e.g., constructive forces such as crustal deformation, volcanic eruptions, and deposition of sediment; destructive forces such as weathering and erosion)
4) Knows the processes involved in the water cycle (e.g., evaporation, condensation, precipitation, surface run-off, percolation) and their effects on climatic patterns
1) copy of the program "The Living Edens: Bhutan"
2) clear glass bottles with small necks (glass soft drink bottles work well)
4) black paper
5) Container with lid
6) Angular gravel
One to three class periods, including time to watch the video segments. The video will take one period. The cloud in a bottle activity and the shake the rocks activity should take one period if done simultaneously.
Bhutan is an area that has a wide topography (video: 1:30) within a short distance. To the north lie high peaks, the center is riddled with hills and valleys while the south is characterized by lowland jungles. The Himalayan highland affect the climate of the entire subcontinent by diverting the monsoon winds, creating rain zones and keeping colder air from central Asia from directly flooding down undeterred.
The word "monsoon" comes from the Arabic word "mauism" which means "season." The monsoon is a wind that changes direction seasonally. From April to October the winds in Bhutan generally blow from southwest to northeast while in the months October to April they reverse and blow northeast to southwest. In the months from August to October, the winds are blowing from a direction that causes them to become laden with warm moisture from flowing over the Bay of Bengal region of the Indian Ocean. As they reach the southeastern front of the Himalayan range, they deposit this moisture leaving Bhutan with over 300 inches of rain each year.
The formation of clouds is due to moist air reaching an area with cooling temperatures and a reduced air pressure. The moisture condenses on minute particles in the air until it become large enough to either be seen as a cloud or to deposit some of the moisture in a form of precipitation. The video shows remarkable footage of the formation of clouds as the air increases elevation and dissipation of the clouds as they begin to descend. The southern section of the Himalayan range is an excellent place for this to happen as warm air begins to rise from near the sea until it encounters the largest mountain range on Earth. As it rises, it loses air pressure and the temperature falls significantly. (See temperature chart) Clouds form and much of the moisture is released. After passing the mountains, the air has lost much of its moisture supply and the following areas are much drier.
Thus for several months of each year, torrential rains strike the mountains of Bhutan and surrounding countries sending water down the valleys carrying loads of eroded rocks, dirt and silt which renew the minerals in the lowlands. The water returns to the sea to begin this cycle anew. The Bhutanese have recognized this recurring pattern and honor it along with the other cyclical patterns of their country.
The flood of water erode the rocks of the mountains as it travels to the sea. The rocks pound together forming smaller and smaller chunks and finally soils. The soils are deposited along the way on the sides of the streams and rivers, as debris fields in the waterways and as mud in the lowlands that change and renew on a yearly basis. These deposits provide enrichment to the soils and allow a wide variety of plants and animals to have developed near the rivers. Some of the rocks particles return to the sea to become the rocks of the future. The Bhutanese recognize the replenishment of the environment by these seasonal changes.
1:30 Clouds come over high ridge and evaporate
2:00 Numerous short scenes of clouds moving
5:40 Clouds forming at top of ridge and evaporating
11:30 Series of monsoon storms as they reach the Himalayas, rain, overflowing stream
32:30 River in Middle Himalayan Mountains showing deposition of materials from above
36:30 River in piedmont region. Note mud flats, grasses and bushes in flood plain and silt
1) Watch the selected portions of the Living Edens: Bhutan video. Discuss what role of water has in each of the segments.
2) Take a clear glass bottle (small plastic ones work to a lesser degree) and place several tablespoons of water inside. Shake the bottle well so the air become saturated and pour out the excess water. Have the student blow into the bottle as hard as possible for as long as possible (the idea is to build up pressure) then release the pressure as fast as they can. A VERY SLIGHT cloud will form in the bottle. It is easier to see if a piece of black paper is next to it.
Tell the students that clouds form on dust particles in the air B such as those given off by the fires in the video or from dust particles picked up by the wind. Light a match, let burn for a short time, then blow out and insert into the bottle so a small amount of smoke is trapped inside. Repeat the directions for forming a cloud. A much more noticeable cloud will form. While the cloud is visible, blow into the bottle again and the cloud will disappear or diminish.
3) Relate the cloud activity to the formation of the clouds in the video.
4) Relate the activity to the Bhutan area by examining the a map of the area and plotting the position of Bhutan, the Bay of Bengal, the direction of the monsoon winds and Himalayan Mountain chain on a map.
5) Take a container with a lid (either thick-walled glass with top or metal with a top) and fill one quarter full of angular gravel. Put a small amount of the gravel to the side to be used for comparison after the activity. Fill the container 95% full of water. Pass the container from student to student and have each one give it 100 shakes. Once the container have circulated, examine the water for cloudiness from rock particles. Compare the rocks that have been shaken to those left for comparison. Discuss how streams break down rocks as they are washed to the sea.
WeatherPost from The Washington Post http://www.weatherpost.com - current and historical climatic data from thousands of cities around the globe
Bhutan Virtual Library http://www.bhutan.org/index2.html - dozens of links about Bhutan
1) Have students draw and label a picture that diagrams the cyclical nature of the water cycle in the Himalayan Mountain range. Students should include a paragraph that describes their drawing. The picture may be assessed by scoring the explanations of the component parts during a class presentation using a rubric.
2) Have students draw and label a picture that diagrams the cyclical nature of rocks in a mountain range. Students should include a paragraph that describes their drawing. The picture may be assessed by scoring the explanations of the component parts during a class presentation using a rubric.
3) Students may be assessed though their participation in the class discussions and activities.
1. Students may investigate the rain shadow areas of different mountain ranges by using web resources. By using a map, major cities on either side of a range can be identified. Weather and historical climatic data may be obtained from the WeatherPost site and analyzed. The address of the site is given above.
2. Students may investigate the effects of floods in their region and the rest of the world by interviewing older residents or doing research. Effects of floods and high water are likely to be evident years after the event so students may visit and take pictures to bring back to the class.