Water on the Move

Setting the Stage:

1. Introduce lesson with graphic of the water cycle using available water cycle posters that can be obtained from most municipal water departments or the USGS web site (http://ga.water.usgs.gov/edu/).

2. Discuss water cycle vocabulary: precipitation, runoff, surface and ground water, evapotranspiration, evaporation, condensation, etc.

3. Discuss and explain meanings of impervious and pervious and point out these areas on school campus site. For example, paved areas are impervious. Natural grassy areas or areas with soft soil are pervious. Note that any dirt area where it is hard and compacted is considered impervious since rainfall cannot penetrate it.

Student Work:

4. Students find 1 to 2 study sites on school campus. These should be areas with different surfaces and where the rain gauge will not be disturbed and where the flagging tape or twine can stay in place for a while. One site is sufficient if it has both impervious and pervious surfaces.

5. Once the site(s) are determined by students and teacher, the length and width of each area should be measured using tools that are available. Using twine or flagging tape, students can measure and mark every 3 feet. If a trundle wheel is available, it is the most convenient tool for measuring. The main difficulty with calculating area comes from irregularly shaped study sites. If site has irregular shapes, try to leave those out and measure area that is rectangular.
Use [wpfilebase tag=file id=1894 tpl=filebrowser /] forms throughout the investigation.

6. After the study areas are marked and measured, determine the amount of rain that falls in the areas using these suggested options:

a. Obtain the rainfall averages using information from resource agencies such as the National Weather bureau, local or state soil conservation service, local meteorologists, state hydrologists or local newspapers. One reliable source is www.usclimatedata.com.

b. Using the annual average for your location (for example, Santa Fe, NM), complete calculations for volume of rain on [wpfilebase tag=file id=1894 tpl=filebrowser /].
Go here for climate data: http://www.usclimatedata.com/climate/new-mexico/united-states/3201c. Measure the amount of rain with a rain gauge and record rain over a period of time.

c. Measure the amount of rain with a rain gauge and record rain over a period of time Calculate an average. You may need to simulate rain by using sprinklers, if no rain falls during project time.

d. Calculate the amount of rain that falls in a given storm when using rain gauges and repeat calculations for volume of rain.

7. Discuss historical rain events in the region. This will be helpful if no significant rain falls during time allotted. One example from the Cloudcroft area occurred in 1941. Canyons were eroded during that rain storm and are still noticeable.

8. Class discussion on where the runoff rainfall flows to for your site. This could be a nearby arroyo, a drain or ditch or a stream. Make predictions on wildlife living in these areas that could benefit from the water.

Lesson Assessments and Extensions:

9. Discuss questions and topics for deeper investigation and research. Students record the results of their investigations, class discussion notes, and written reports in science notebooks:

a. How does the volume of rain for the measured site compare between the climate data averages and your actual rain event measured volume?

b. Since New Mexico typically does not receive large amount of dependable rain, and since drought conditions often occur and persist for long periods of time, why would it be important to ensure that your school site’s rainfall does not just runoff, but rather collect in areas where it can be absorbed and add to plant growth?

c. What could you do as a student group to change your school campus to allow for more pervious natural areas?

d. Where does the water from rainfall go when it leaves the study site?

e. How much water is absorbed by the different surfaces on the study site? If there are two sites, how do they compare? How are they different?

f. What types of potential pollutants does the water come in contact with? (Is there a school parking lot nearby where automotive oils could runoff during rain events)?

g. Where is the location of the nearest wildlife habitat that receives the site’s runoff? (Is it a nearby arroyo?)

h. Conduct research on wildlife in your area that benefits from rain runoff.

i. How do people use the water between the time it leaves the site and arrives in the wildlife habitat?

j. What are some of the positive and negative effects that the water may have on the whole environment at various points on its journey? (Consider flash flooding that occurs in New Mexico).