[CSCI 3665] Interactive Data Visualization

Instructor: Clare Bates Congdon

Collaborator: Erik Nelson

Contributors: Son D. Ngo, James Boyle, and Do Yeun Kim

Final Project: Visualizing data provided by on-campus collaborators

Project Description

This project was inspired by a working paper by Professor Erik Nelson of Bowdoin Department of Economics (Bowdoin College, Maine), titled "Measuring the Relative Importaance of Different Agricultural Inputs to Global and Regional Crop Yield Growth since 1975," which can be found here. This project is also a part of the Agricultural and Resource Economics Commons. The paper attempts to study and analyze various factors - including but not limited to crop types, temperature, and fertilizer use - that may affect crop yield both globally and regionally, with focus on possible effects of global warming on the crop yield, as concerns for global warming is consistently raised.

Here, we used the data from Professor Nelson's paper in hopes to answer, through interactive visualization, some of the questions raised, which are shown below. These questions were formulated with some of the interests of Professor Nelson in mind, with focus on change over time in crop yield. The agricultural factors and attributes of interest are as follows:

• Measurements of crop yields
• Temperature, precipitation, and climate
• Crop type choices
• Agricultural technologies
• Fertilizer use
• Investments such as irrigation
• Soil quality

Scatter Plot

The questions we are trying to answer with this visualization are:

"How does crop yield change over time with respect to daytime and nighttime temperature?"
"Does precipitation factor into the relationship?"

This scatter plot provides an option to be animated over time, in which the user will see how the each country's total crop yield per ha (hectare, 1 ha = 2.47 acre) changes with respect to its corresponding average temperature, both daytime and nighttime, from 1975 to 2002. There might be some delay between the animation-controlling buttons and the animation. The animation will reset if the data is changed (unit for yield per ha, temperature type, or number of countries to display). In order to achieve the best visual effects, please wait until the animation is finished, or pressed "Restart" before changing the data. Please note that the number of countries shown is based on the total crop yield in terms of absolute amount, not by hactare. If prompted to show the top 10 countries, the plots represent the top 10 countries that contributed the most crop yield in the year 1975.

Possible Interactions

• Click on buttons to play, pause, stop, reset, or rewind the animation. When the anmiation finishes, make sure to press "reset" to reset the animation.
• The red border of the "rewind" button indicates that the animation is in rewinding state. To revert, click on the button again.
• Click on "Speed up" and "Slow down" buttons to accelerate or decelerate animation.
• Click on the radio/circular buttons to change the x-variable and/or y-variable of the graph. Note that this will reset the animation to 1975.
  • X-variables: average daytime temperature in Celsius or average nighttime temperature in Celsius.
  • Y-variables: crop yields in tons/ha or crop yields in million Kcals/ha.
• Hover over a dot/circle to obtain more detailed data regarding the corresponding country.
• Adjust the slider at the top to change the number of countries to display.

Geomap

The questions we are trying to answer with this visualization are:

"How did a country's crop yield change in relationship with other countries across the globe?"
"How does that relationship change over time?"

This choropleth displays crop yield, in either of the two units, of the countries for a given year, between 1975 and 2002. The country indicator (orange dot) takes some time to be reset. In order to see the indicator properly change in size, please wait for a second or two before clicking a different country. The information box is generated near the position where the mouse enters the country; it is recommended that the user re-enters the country with the mouse (hovering) accordingly for more effective/aesthetic visualization.

Possible Interactions

• Use the slider to input the year of interest to be visualized. The number (year) at the top of the visualization will change accordingly.
• Hovering over a country will display an information box with some level of detail, where only the name of the country is displayed in global scope while fertilizer usage (kg/ha) and crop composition are also displayed when zoomed in.
• Clicking a country will allow the user to zoom into the country to allow facilitated observation. Reclicking on the same country will allow the user to zoom out, and clicking a different country within the visible area will allow the user to move on to the clicked country.

External Links
To Son's homepage
To James' homepage
To Do's homepage