Draft 2:Evaporation at Western Pond as Compared Seasonally

I. Introduction

Our group is interested in studying Western Pond, specifically the rate of evaporation of water from the pond under different environmental conditions. We intend to collect readings of air and water temperature, and using models and equations to estimate the average rate of evaporation from the pond under these different conditions. We have also added wind velocity into the equation. We plan on using the average wind velocity each day and seeing if that has any effect. Based on previous instruction we hypothesize that evaporation rates will be higher under conditions with relatively warmer air and water temperatures.
Evaporation methods are used to purify water and dispose of hazardous waste (Filtration & Separation p.429). If we are able to determine the evaporation rates the data could be used in other studies to determine how healthy the pond is under different conditions. Someone would be able to determine how much harmful waste evaporates from the pond. At certain times of the year, under different environmental conditions, the pond might cycle out pollution naturally and be healthier.

II. Relevance

We have read several science journal articles that deal with evaporation from varying experimental angles. A Sweden-based engineering firm studied methods for hazardous waste disposal involving evaporation (Filtration & Separation p.429). Some scientists have studied evaporation rates in different types of soils (Soil Science Society of America Journal pp.341-346). Studies have been done that determines that greater surface area increases evaporation yields (Solar Energy pp.261-266). A group of scientists has found evidence that evaporation acts as a cooling method for bodies of water, much like the act of sweating cools the human body (Science News p.69). Winds hinder rainfall, and push evaporated moisture out of areas that need water (Natural History p.48-49). In a study of evaporation in oat and rye crop fields, scientists determined that there is seasonal difference in evaporation rates (Journal of Soil and Water Conservation pp.263-268).
All of these studies' results can be implemented in the real world. We can take their data and convert it to many aspects of society. Hazardous waste can be disposed of more efficiently and effectively. Farmers can tell how much water they should expect to lose from their soils due to evaporation. Companies like fish hatcheries or water treatment plants can determine evaporation rates of different-sized tanks and basins. Perhaps in the future we will use evaporation to cool off things such as houses or cars. Even seasonal evaporation numbers can be important to companies, which are looking at locating in certain areas of the country or world.

III. Materials and Methods

Our group proposes to set up five evaporation pans at varying locations around Western Pond, including open spaces, wooded spaces, and one next to the boat house. From these five pans we will measure daily evaporation and record variables including air and water temperature. In addition to these observations, Professor John Klink will provide us with daily air temperature, wind velocity, and humidity measurements taken from the Oxford area. Our group will also be taking observations from control pans located in Boyd Hall. We plan to record the same sets of data from these pans.
Combining these sets of observations we hope to estimate evaporation rates of Western Pond in different conditions. Our experiments will be statistically sound because of the frequency of data collections, and number of variables accounted for. The use of control pans helps us compare unstable to stable environments.
Materials used in our study will be pans to house the water, chicken wire to cover the pans from foul play (swans, people, etc), and thermometers to record temperatures. In the lab we will also be using fans to simulate wind velocity, and heating and cooling mechanisms (eg. ice cubes, refrigerator, lamps) to control temperature.
For the in-class lab we propose to set up five pans in Boyd Hall simulating different conditions. These pans will be set up as follows: one control pan (room water temperature, no wind), one pan (room water temperature, with wind), one pan (warm water, no wind), one pan (warm water, with wind), and one pan (smaller surface area than control pan, room water temperature, no wind). 24 hours prior to the lab, we will take measurements on all of the pans. The day of the lab we will disclose these numbers to the class. We will then have them hypothesize which variables will have which effects on the rate of evaporation. The class will be split into five groups, each assigned to a specific pan. They will measure the current water level, and sharing this with the rest of the class, come together and make conclusions about their data.
We plan on measuring the evaporation around Western Pond starting this week. It will most likely be Friday October 1. We will measure everyday up through November 19, the Friday before Thanksgiving break. The rest of the time will be spent examining data developing conclusions, and writing the lab report.

Tray one Water Level Air Temp Water Temp Humidity Wind Velocity
Day 1
Day 2
Day 3

(sample chart) one data sheet for each tray.(table did not convert from word to the web)

Cited Works

"A Drought's Unyielding Cycle", by Kenneth Kunkel; Natural History Jan. 1989 pp 48-49
"Do Clouds Provide a Greenhouse Thermostat?" Science News Aug. 1 1992 p.69
"Spatial Variability of Evaporation along Two Transects of a Bare Soil" by R.J. Lascano and J.L. Hatfield; Soil Science Society of America Journal March 1992 pp. 341-346
"Surface energy balance partitioning over rye and oats cover crops in central Iowa" by J.H. Prueger, J.L. Hatfield and T.J. Sauer; Journal of Soil and Water Conservation Third Quarter 1998 pp. 263-268
"Waste Not Want Not - With the Help of Evaporation" Filtration and Separation June 1997 pp. 425-429

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