Week 1 Site Reviews – LA/OC Real-time Precipitation

As a field hydrologist-in-training, I often find myself looking at real-time precipitation maps to see when exactly it started to rain, how much it rained, where it’s raining, etc.  These are key questions when you’re waiting to drive out to your study site to collect storm water samples.  I help a PhD student grab Station Fire runoff samples after the huge 2009 fire in the San Gabriel Mountains.  We collected samples every 1-2 hours during and immediately after the storm.  For this reason, I came to depend on real-time precipitation maps.  Currently, I use the Los Angeles Department of Public Works (LADPW) website frequently for research and I also like to check Orange County Department of Public Works’ (OCDPW) website when I’m at home visiting my family.  For this assignment, I decided to evaluate the two websites.


Site #1: Los Angeles County Real-time Precipitation (http://dpw.lacounty.gov/wrd/precip/alert_rain/index.cfm)

LADPW provides real-time precipitation data in this static map.  Gauges throughout the county are displayed in one view and links provide detailed information for each gauge.  A stream network is also provided in the background.  Surrounding county names are also named appropriately.  Above the map are options to change the temporal resolution of the data (last 1 hour, 3 hours, 6 hours, etc).  After clicking on the link, a new map is loaded with the appropriate data.  Freeways are the only spatial referencing tool on this map, aside from the county boundary lines.  I’m not familiar with this map interface (i.e. it’s not Google, Bing, etc).

PROs: maps fits on a typical computer screen, gauges are labeled, full time-series of data at each gauge is available

CONs: no interactive panning, no zooming option, lack of spatial referencing (i.e. topography would be helpful)

Overall, this maps is not very exciting to look at or work with and it would definitely be nice if it had a better interface.   It provides a large amount of data, but the blue bar on the top with the different temporal scales is not quite so easy to find as it is of of the map and it blends in with the browser since there are no spaces before.  A larger font size across the entire website would also be nice.


Site #2: Orange County Real-time Precipitation (http://www.ocwatersheds.com/StormRainFall.aspx)

OCDPW’s website has a more up-to-date look to the way they display their data.  It’s built on a dynamic, simple, and familiar map made by Google (roads, cities, labels, land cover, etc are already in there by default, but you can also change to the satellite or terrain modes).  Gauges are not labeled, but the gauge name and number show up when you hold your cursor over the black rectangles with precipitation values.  When you click on the values, the total precipitation recorded during those different time-scales is shown. A drop-down menu provides the option to look at different temporal scales of data (i.e. 15-minute, 30-minutes, 1 hour, etc) and only the GoogleMap refreshes (not the entire browser).  I believe this makes the website faster to load.

PROs: google maps! (many useful built-in functions),  panning, zooming, display versatility /customization, small panning window in the bottom right corner, option to display only gauges recording data, fast map refreshing speed

CONs: no precipitation time-series (vector)

Overall, the Google Map interface greatly enhances the utility of this website.  These built-in functions are familiar to a wide range of people and there won’t be any learning involved on how to use to the website.  (This saves time and energy.)  Although data is available on a wider range of time-scales, not all of the real-time data is actually provided.  Only totals for each temporal scale are provided; thus, this limits its usefulness for people who need it real-time (e.g. researchers).



I found the OCDPW website to be better than the LADPW website because it’s easier to use, more intuitive, and aesthetically pleasing.  For an average user, it provides enough information.  If I were to build a similar website, I would definitely improve the information on the pop-up to have a link to high temporal resolution data.  With that addition, the OCDPW website would have all the PROs found in both counties’ websites.

Based on this comparison, I definitely would want to have zooming and panning capabilities for my group’s project.  I feel that those two are critical characteristics of a good web map.  I am also a big fan of Google products and would like to incorporate them into my team’s project.

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