Thursday, September 27, 2012

Ocmulgee River

For this lab we visited the Ocmulgee River and measured the depth of the river, the flow rate of the water, and the amount of clams? at various depths.

To measure the depth of the river at various points, or the elevation below the river bank, there were two poles with clearly marked measurements.  Attaching the poles was a string with an object attached that helped determine whether the string was parallel to the water line.  Two people would each hold a pole and stand at different points across the river.  They would then move the string so that it was parallel and record the distance from the string to the height of the water on each pole.  The difference of these two measurements would tell how deep one part of the river was in relation to the other.

To measure the flow rate of the water, one person would stand upstream with a floating object.  The other person would stand downstream at a particular distance from the first  person.  The first person would release the object from upstream and someone would use a stopwatch to measure the time it took for the object to reach the person downstream.  The flow rate can be calculated by dividing the distance between the person upstream and the person downstream by the time it took for the object to travel downstream to that person.

We also used different sized screens to collect sand and sift through it to find small clams in the river.  We were looking to see if there was a higher concentration of clams at a particular depth of the river.



Thursday, September 6, 2012

Hurricane Isaac

Hurricane Isaac

Lab #1 - Maps

Choropleth Map
A choropleth map uses varying colors to visually display statistical differences across a region, looking at things such as population density or, as seen above, voter turnout as a percentage of voting age population.

Dot Density Map
Dot density maps use dots to visually display the concentration of a particular phenomena in an area.  Dots are typically used to represent a larger statistic in that particular area.

Proportional Symbol Map
Proportional symbol maps use symbols of varying sizes to represent a particular statistic in an area.  Typically, the larger the symbol, the larger the statistic of whatever is being represented.

Isopleth Map
Isopleth maps use curved lines to stand for a particular number.  Typically, the statistic is lower below the line, higher above the line, and somewhere in the middle between two lines.  In the map above, the the average level of precipitation in inches in Georgia, from the Florida state line to that first large contour line, would be between 55 and 50.