Interactive visualization of water quality data from the island of Hawaii

I was talking to a friend of mine last week about creative ways to interact with data linked to specific geographical locations. The following visualization is an experiment that arose from the conversation.

Hover over the points to see the name of the sample location. Chose ‘Map’ from either of the drop down lists to see a map of all the sample locations:

The data is from the Clean Water Branch of the Hawaii State Department of Health. It was downloaded on September 20th. The graphs show the most recent data for each station on the Island of Hawaii.

Points to notice:

  • A high Enterococci measurement was recorded at the Waiulaula station on 8/22/12.
  • The Waiulaula sample also has the lowest salinity value.
  • There is a strong correlation between Dissolved Oxygen and percent oxygen saturation (which makes sense).
  • More interestingly, there is also a correlation between pH and Dissolved Oxygen. This also makes sense assuming the differences in oxygen concentrations are due to excess respiration in the samples with the lowest oxygen concentrations. Because, along with lowering the oxygen concentration, respiration raises the carbon dioxide concentration. Since carbon dioxide acts as an acid in water, more carbon dioxide should mean a lower pH.
the map is a screen grab from google maps
made using the d3.js library

The complete list of sample dates and locations:

  • Kahaluu Beach Park – 9/13/12
  • Kailua Pier Sta. – 9/13/12
  • Kailua Pier Sta. – 9/13/12
  • Puako Middle of Lot06 – 9/13/12
  • Anaehoomalu Bay – 9/13/12
  • OTEC – 9/13/12
  • Pelekane – 9/12/12
  • Kauhako Bay – Hookena – 9/11/12
  • Kealakekua Bay (Curio Stand) – 9/11/12
  • Milolii – 9/11/12
  • Banyan’s Surfing Area – 9/11/12
  • Honaunau Bay – 2 Step – 9/11/12
  • Kawaihae LST Landing – 9/5/12
  • Mauna Kea Beach South End – 9/5/12
  • Holoholokai Beach Park – 9/5/12
  • Pauoa Bay – 9/5/12
  • Hapuna Beach – 9/4/12
  • Magic Sands – 9/4/12
  • Kailua Pier Sta. A – 8/28/12
  • Keauhou Bay – 8/28/12
  • Kona Coast Beach Park – 8/28/12
  • Kua Bay – 8/28/12
  • Pine Trees – 8/28/12
  • Waiulaula – 8/22/12
  • Honuapo Landing – 8/9/12
  • Punaluu Beach Park2 – 8/9/12