Scientific Method ? Deforestation in Rhondonia, Brazil
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.
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.
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.
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.
Please enter your wet-bulb temperature and then choose either Fahrenheit or 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.
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.
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.
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.