Time Lapse Photography at Lalakea and Hakalau Stream
Time-lapse camera photography of Lalakea Stream. The digital camera is in a
waterproof casing and
attached to an ohia tree above the stream. A timer has been set to take pictures every day at 1:00 pm.
Pictures are then downloaded from the camera to the computer every 30 days or so. In this movie, every day is a different frame. The first picture was taken on September 20, 2004 and the last picture was taken on December 2, 2004. When watching this movie, notice the large flood event towards the end of the movie. The stream came up suddenly in just one day and flooded on November 15, 2004, and came down quickly.
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Hakalau Stream also has a time-lapse camera placed on the main Hawai'i Belt Highway bridge crossing.
The pictures cover the same time period as Lalakea Stream, from September 20 until December 2, 2004. This will allow us to compare stream flow on a daily basis in a high elevation area such as Lalakea Stream (2000 ft) versus a much larger and lower portion of the watershed at Hakalau Stream right as it enters the ocean. Note on these time lapse photos that Hakalau Stream is much more variable while the upper Lalakea Stream maintains a more stable and constant flow. Any thoughts on why this might be?
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Pictures taken at Lalakea and Hakalau Stream prior to and during the November 15, 2004 flood.
Why are we doing this?
The objective of time-lapse camera photography is a step in the development of a time-lapse digital imaging and classification process aimed at the rapid assessment of the discharge to aquatic habitat relationship. This process will fill a critical need for a simple, cost-effective, and quantitatively accurate technique for predicting the effect of changing discharge levels on the aquatic habitats.
We are putting in the camera to quantify the amount of aquatic habitat available at differing stream flows, particularly during high flows when it is unsafe and not practical to go in the stream and take quantitative habitat measurements.