Our initial purpose is to compare the methods of a man-made and read rain gauge to that of a manufactured, electronically read rain gauge. Because "small elevation differences can cause considerable changes in amounts of rainfall" (Campbell 5), we plan to place eight hand-made gauges in four different locations on the Northeast side of the Art Museum Building (two on the top of a hill, two in the middle of a hill, two at the bottom of a hill, and two in an open field). This arrangement will give us the best chance at accuracy, therefore, enabling a true comparison. Each gauge will be subject to experimental error because of varying exposure to wind and evaporation. By placing these gauges at different elevations and different wind exposures, we will be able to calculate an approximate daily value by averaging the eight numbers together to account for any error caused by wind. Evaporation, however, is inevitable. We will then compare these results to that of Hayes Cummins' electronic device. Each location on the hill will be void of any coverage or foliage obstruction to guarantee more accurate and precise data collection.
Throughout further experimentation, we have found that accidental error may have great impact on the accuracy of our data. Though we had expected to reduce error by placing the gauges in the selected location, we ran into other obstacles. First, we found that moisture from heavy rainfall days caused the tape on our gauges to come undone. As a result of this, the rain collectors fell to the ground and no longer positioned to collect comparable data. Some of the beakers laying on their sides, therefore unable to collect any rain at all. In this case we had to leave out this data. We have also run into some difficulty with tampering. The location is subject to high traffic because it is along the frisbee golf course and people passing may have knocked the stakes out of the gound or broken the glass gauges. Our best solution for these problems is to exclude the data (which are significant outliers or non existent) and leave blanks in our table. Though we had hoped not to face such problems, we have decided that this will be the best way to continue our lab. We will ultimately just have less data to work with.
Our hypothesis is that Hayes Cummins' electronic rain gauge and our man-made rain gauges will yield different results. In other words, we expect that the electronic rain gauge will be more representative of actual rainfall. This hypothesis is similar to the clover lab in that we will use the t test to prove or disprove our hypothesis. We plan to enter our data into statview and we expect to get a p value of <.05. There will be a greater distance between the means of the two data sources.
We decided on this project by process of elimination. Our initial idea was to deal with the chlorophyll levels in various tree leaves, where we soon found multiple obstacles in our process and experimental design. With the leaves already starting to change color, we ran out of time and were skeptical about the accuracy our results would yield. Our second experimental idea was going to involve observation of gender dominance through handholding. This was going to be a human behavioral study. The difficulty we met in this case was lack of resources and the anticipation of insufficient data. We came upon our final and current idea by returning to our original interest in nature within our surrounding environment. Our last minute change of plans turned out to accommodate a more independent student based lab. This idea reduces the dependency we had previously placed on the science lab and equipment. Therefore, we decided to study the methods of rainfall collection. After making this decision, we encountered problems that hindered our rainfall collection. The rainfall collectors were too small for the amount of rain we received, and there were too few rainfall collectors to make our sample representative. Therefore, we doubled the amount of rainfall collectors and equipped them all with larger containers for collecting rainfall. This has proven very effective considering the data we will be forced to leave out. Had we only used four gauges, we could have run into mcuh greater problems!
Next we hope to apply the ideas and statistical methods that we learned in the clover lab to a more useful and relevant topic, accomplishing a better understanding of statistical methods for our class and ourselves. This will allow our class and us to become more familiar with the practical uses of stat view, p values, and t tests.
Rain has been an important factor of life for human beings since Ancient Egyptian times. They relied on it much like we do for the growth of their food. They portrayed rain as having originated from a deity. Aristotle, a philosopher of Greco-roman times, was the first to separate rain from astrology. He was the first to construct theories as to why it rains. Isaac Newton added to the theories on rainfall and weather. Hundreds of years later people are studying the same question as past philosophers and scientists (Middleton 57).
The study and recording of rainfall is beneficial to all mankind; you can see it on weather channels or the news. Such recordings influence the daily lives of humans through effects on crops, allergies, and traffic. Everyday, we trust the weathermen to tell us what the daily rainfall is, but we are analyzing it ourselves in our experiment. These all-knowing weathermen use practically the same devices and techniques as we will but more technically advanced, like Hayes Cummins' electronic rain gauge. Just as many forecasters and airports, we will use a rain gauge type that was invented a hundred years ago. It will consist of a collecting funnel that drains the water into a tall measuring container. We will then record the daily rainfall amount (USAToday.com). Another possible method of rainfall collection can be taken from the tipping bucket rain gauge. This contraption consists of two buckets that will tip when approximately 0.1 inches of rain is collected. This will signal an attached recorder and calculate the rainfall over a period of time (USAToday.com). Another type of rain gauge is the optical rain gauge, which "estimates rainfall from the number density of the rain drops" (Encyclopedia of Weather and Climate 443). It accomplishes this by emitting an infrared laser about a meter long, which fluctuates as drops pass. This estimates the amount of rain by how fast the beam is moved. There are many ways to measure rainfall electronically: "weighing the amount of accumulated water, using float valve to measure the height of the water column, or measuring the electrical capacitance of the water column" (Encyclopedia of Weather and Climate 442). This experiment will lead us to our conclusion--that a man-made rain gauge is sgnificantly different in reading rainfall amount than that of an electronic rain gauge.
· (8) 1 meter long stakes
· (1) graduated cylinder
· (8) uniform rainfall containers (jars)
· (8) empty 2-liter, plastic, Coke bottles
· (8) plastic funnels with mouths approximately 20 centimeters in diameter
· Duct Tape
· Hayes Cummins' electronic rain gauge (website listed below)
· Construct the eight rain gauges by placing a rainfall container into each of the four 2-liter bottles, attaching a funnel to the mouth of each container with Duck tape, and attaching the above collecting device with Duck tape to stakes.
· Place entire device into the soil so that each are level and equidistant to the ground.
· Place two stakes in each of four planned locations that are void of any obstruction due to trees and buildings.
· Record daily amount of rainfall at the same time, 7pm, everyday, keeping in mind necessary conversions from milliliters to inches.
· Empty recorded rainfall by removing the tape strip from the bottom and pouring rain out of collecting containers.
· Visit Hayes Cummins web site to record the daily readings of his rain gauge
· Continue this procedure for approximately five to six weeks.
· Enter data in Statview program and analyze the t-test results and p-values.
In-Class Rainfall Collection
· For our class lab, we plan to have the students take the daily reading of all nine gauges. We will display our data and results regarding our findings, allowing the class to see if our results support the null hypothesis.
Date Hayes Gauge 1 Gauge 2 Gauge 3 Gauge 4 Gauge5 Gauge6 Gauge7 Gauge8
When preparing to conduct the experiment in class, we again met some difficulty. First, the rain gauges had been tampered with. Some had been removed from the ground and the tape had come undone on some of them. Also, it had not rained at all in the last twenty four hours so there was no data for the class to collect. We decided that in order to still show the class how we conducted our experiment each day, we would fill the gauges with water to represent real rainfall. The class took these measurements and were able to see how we created the gauges and how we read them. Next, we charted our recorded data in the classroom and had each group avergage the daily numbers together. We then had them convert the data from mililiters to cubic centimeters to cubic inches. This gave them an understanding of how rainfall is measured and what calculations had to be done to get the correct units.
We had hoped that averaging the eight daily rain gauge measurements would ensure statistically sound results by eliminating as much human error as possible. This has not been the case, but with our best data we will continue to compare our results to that of Hayes. Our lab is a simple and productive way of conducting an experiment that is comprehensible to the average student. Even if the data is not as ideal as expected, we will still have the chance to work with statview and the concept of p values. The class will not be expected to work the recorded data because we plan to give an in depth explanation of our procedures and findings. They collected data for one day that will not be added into our findings because it was not applicable. We started collecting daily data October 17th and will continue through November 21st.
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