In one of the major regions of deforestation, the province of Rhondonia, Brazil,
the rainfall has been severely and or completely stopped. Theory: As the
tropical rainforest of Rhondonia, Brazil is leveled for farmland, rainfall is
significantly and directly reduced. Rainfall is reduced because there are fewer
trees to return water vapor to the air through tree transpiration, or water
evaporation through trees. Relative humidity is the amount of water vapor in the
air compared with the amount of vapor needed to make the air saturated at the
air’s current temperature. The point past saturation is precipitation, or
rainfall. If deforestation is the cause of decreased rainfall, then decreased
average relative humidity will be evident. Experimental Design: In order, to
isolate deforestation as the primary factor causing decreased rainfall, tests
will be conducted to measure relative humidity. A sling psychrometer will be
used to gain these measurements. http://www.taftan.com/thermodynamics/HYGROMT.HTM
It is used to measure the amount of moisture in the air. The dry-bulb
thermometer measures the air temperature, and the wet-bulb measures the lowest
temperature that can be obtained by evaporating water into the air at constant
pressure. A calculator will be used to convert to relative humidity. http://www.srh.noaa.gov/elp/wxcalc/rh.html
El Paso National Weather Service Office's weather calculator This converter will
take the wet-bulb temperature, the air temperature and the current uncorrected
pressure and calculates the relative humidity and dewpoint. Please enter your
air temperature and then choose either Fahrenheit or Celsius. Fahrenheit Celsius
Please enter your wet-bulb temperature and then choose either Fahrenheit or
Celsius. Fahrenheit Celsius Please enter your actual station pressure (not sea
level pressure) and then choose either millibars or inches of Mercury. Millibars
Inches of Mercury Relative humidity measurements will be taken every day for one
year. The measurements will be taken at different stations in the rainforest.
Four stations will be located no further than 10 miles from current areas of
deforestation. Four other stations will be located at the interior of the
rainforest, and at least 50 miles from recent deforestation. After these
measurements are taken, they will be analyzed in three different ways. Run
Experiment: The daily measurements were tracked for one year. Comparison 1 - The
recent relative humidity measurements of the rainforest will be compared to
previous figures of relative humidity. The average off all relative humidity
measurements will be compared to the relative humidity of the rainforest before
this experiment. Comparison 2 – Recent relative humidity measurements of
different regions of the rainforest will be compared. Measurements from areas
near to sites of deforestation will be compared to measurements from sites
further from areas of deforestation. Comparison 3 – Measurements towards the
end of the study will be compared to measurements at the end of the study.
Average relative humidity measurements for the first month of the study will be
compared to the average from the last month. Analysis: Comparison 1 - Taking the
average of all measurements and comparing it to the average relative humidity
from the prior year it was found that the average relative humidity had dropped
one percent. Comparison 2 – Taking the average of each stations relative
humidity, it was found that all stations within 10 miles from deforestation had
an average of two percent lower that stations at least 50 miles from
deforestation. Comparison 3 – Taking the average relative humidity for the
last month from all stations and comparing it to the first months average it was
found that the average had dropped .5 percent over the year. Conclusion: The
findings suggest that deforestation is affecting the amount of rainfall in
Brazil. The deforestation will not only continue to affect rainfall but will
lead to increased global warming as evaporative cooling decreases. Evaporative
cooling takes place when solar energy, or heat, is used to convert water from
trees to water vapor or humidity.