Recognizing subtle patterns in large data sets that were collected over many years is a challenge. Traditional 2D and 3D visualization techniques such as line/scatter or bar plots are adequate for basic analysis but fall short when one needs to detect both low- and high-frequency cyclical patterns.
Dr. Richard Koehler, CEO of Visual Data Analytics, developed a new technique to visualize time-series data. Both large and small data patterns practically jump off the screen with Dr. Koehler's raster maps.
To learn more about Dr. Koehler's work, check out the webinar recording where he presented on Data Visualization and Analysis of Time Series Using Surfer. You can also read more about the flow rates of the Colorado River at Lees Ferry, AZ. Try out this visualization technique for yourself in Surfer.
Below are a few examples of raster maps and the patterns that can be seen.
1. Glen Canyon Dam regulation – The hydroelectric dam became operational. The flow patterns before and after the dam are striking and easy to see.
2. Spring Snow runoff – The beginning and ending of each year’s snowmelt can be seen simply by noting where days with blue start and end.
3.Drought – A period of lower snowpack in the Rocky Mountains that left the Colorado River flowing at record-low levels. 4. Sundays and Holidays – Lower flow rates as a result of lower electricity demands on Sundays or holidays. 5. Individual Storms and artificial floods – Isolated blue colors lasting from a few days to many weeks indicate heavy runoff from a major storm or artificial floods.
Ship departures and arrivals are dependent on the timing of the tides. The above tide map demonstrates the variety of low and high tides throughout the year due to the ever-changing positions of the Earth, Moon, and Sun. Represented by the grey line is the daily sunrise and sunset times which is important for safe vessel movement.
Peak passages and seasonal variability of the Chinook salmon migration is easy to discern over the past 71 years. The large fall run is quickly visible along with the smaller spring and summer run. Also notable is the steady increase of salmon in recent years during the August through September run.