12 replies to this topic

[peanut]

Here at LCRA (Lower Colorado River Authority) we have just updated our water quality data website:

http://waterquality.lcra.org

The map interface now uses the Google Maps API with watersheds, rivers, and water quality monitoring locations overlayed on top. Using the interface water quality data for the entire Colorado River Basin in Texas can be retrieved.

Any comments are appreciated.

Rich

[benbakelaar]

Can't wait to check it out! But it looks like right now your server is down...

[Hans van der Maarel]

Has the server been Cartotalked (instead of Slashdotted)...

[MapMedia]

Nice. I like the way you got the hydrology to draw in and the sites are accurate, at first glance.
Lots of data - wow! Data tables wouldn't pop-up using Firefox (maybe my settings). Explorer was fine.

Some next step ideas:

A. Organize list of wq parameters by category: physical, biological, chemical, OR Conventional, Metals, Organics, fish tissue, and hydro (flow, erosion, antecedent days, etc). I was interested in getting a view of some key health criteria, but they were scattered across the large table.

B. Would be SO COOL to be able to graph one or two parameters in a time series plot. As it is, I was able to copy/paste the table into Excel and have at it, but, depending who is the target user(s), would also be great to see applicable water quality objective (Texas and US EPA) either at the bottom of the table or also on the chart.

C. Is there a 'reverse engineering' option? If I wanted to see on the Google map, the sites where mercury data are (or their levels), then get a table with all of this data? Also, would be neat to have a button to d/l entire database with lat/long of sites. (I did find a way to grab conventional wq data by site on the other GUI: CRWN water quality data (also very useful).


Before going freelance, I was a GIS analyst in water quality consulting in California for 5 years. I created a host of water quality data GUIs for clients - and I think your Google API is pretty slick (clean and efficient).

[Martin Gamache]

On Firefox here too, tables won't pop up for sites from the map.

Points never appeared on the river always with an offset, should be easy to fix...probably datum related.

I kept zooming in to see if the points would eventually line up but they did not. It might be nice to force the map to a sat image a larger scales since the map data doesn't look so good zoomed in, or go to a more suitable river dataset. It looks kinda blocky.

The tables need some work. time to pull out the Tufte books. Very data rich but little to no structure. They also should be resizable. I was having some problem with the minimizing tabs etc...


In terms of mapping the data dynamically SVG may be a good choice.

[peanut]

Can't wait to check it out! But it looks like right now your server is down...

The server was down for a little while last nite. It is back up now.

Rich

[peanut]

Thanks for your comments so far!

I don't see the problem with firefox on my browser. The data tables do come up in a pop up window, but even when I alter the pop up window settings in Firefox I don't see any problems with it. Do you guys have the Google toolbar installed or something like that?

There are two thing going on with some of the water quality site locations. When you are zoomed pretty far out on the Google Maps API the markers seem to offset a bit. When you zoom further in they match the true location. Unfortunately many of the coordinates for the water quality monitoring locations are off because they were taken from the side of the road or parking lots instead of right at the river. TCEQ (the agency from where we get the coordinate data) is continually working on adjusting the correctness of the coordinates.

In the future we will be reworking the tabular portion of the site and grouping some of the parameters by categories as suggested here.

Charting is also something we are looking at for the future.

I will consider switching to satellite or hybrid and turning off the river dataset when the map is zoomed in.

Thanks again for the comments!

Rich

[benbakelaar]

I have a few comments forthcoming, but one burning question... what was your process for creating/overlaying the custom tileset? Some people do a bounding box and then stretch the image to match, but your polygon borders look unstretched. Did you just eyeball it on each zoom level?

[peanut]

I have a few comments forthcoming, but one burning question... what was your process for creating/overlaying the custom tileset? Some people do a bounding box and then stretch the image to match, but your polygon borders look unstretched. Did you just eyeball it on each zoom level?

I used the method outlined in Mike Williams tutorial at the following URL:

http://www.econym.de...ayeroverlay.htm

It is actually fairly straightforward. I made a somewhat generalized shapefile out of watersheds dataset and then I converted it to KML. You can render KML files as tiles on maps.google.com as shown at this URL:

http://www.econym.de...glemaps/kml.htm

The Google Maps API allows you to add these overlays to custom maps after version 2.61.

It is sort of a black box to me, but it seems that Googles servers when directed to a KML file on your webserver will take the KML file and carve it up into transparent PNGs at all of its zoom levels and then serves the tranparent PNGs as overlays to the map. There seems to be a limit of about 1 meg on the size of the KML file Google will accept.

Rich

[CHART]

Tables worked fine for me with Firefox.
Interesting use of Google maps.

- I like the polygon overlay. (however no indication on what they represent?)
- Lot's of NO Data fields in the tables (but then again I know nothing about water quality parameters)
- Maybe a search engine...or a link from the table listing back to the location on Google.
(is that possible with google MashUPs?)
- What is the intended user base?
The map interface is nice but I think the table listing does the job on its own.


My two cents...

[peanut]

Tables worked fine for me with Firefox.
Interesting use of Google maps.

- I like the polygon overlay. (however no indication on what they represent?)
- Lot's of NO Data fields in the tables (but then again I know nothing about water quality parameters)
- Maybe a search engine...or a link from the table listing back to the location on Google.
(is that possible with google MashUPs?)
- What is the intended user base?
The map interface is nice but I think the table listing does the job on its own.


My two cents...

The polygons represent smaller river basins within the Colorado River basin in Texas. There is a small legend indicating the basin names just below the map.

A link back to the location on Google sounds like a good idea. Will look into that.

Our typical users are water quality professionals and graduate students looking for water quality data.

Thanks for your comments.

Rich

[CHART]

Tables worked fine for me with Firefox.
Interesting use of Google maps.

- I like the polygon overlay. (however no indication on what they represent?)
- Lot's of NO Data fields in the tables (but then again I know nothing about water quality parameters)
- Maybe a search engine...or a link from the table listing back to the location on Google.
(is that possible with google MashUPs?)
- What is the intended user base?
The map interface is nice but I think the table listing does the job on its own.


My two cents...

The polygons represent smaller river basins within the Colorado River basin in Texas. There is a small legend indicating the basin names just below the map.

A link back to the location on Google sounds like a good idea. Will look into that.

Our typical users are water quality professionals and graduate students looking for water quality data.

Thanks for your comments.

Rich

Well well I overlooked the legend...
With a legend it makes the map more useful, then when I first review it.

[peanut]

Well well I overlooked the legend...
With a legend it makes the map more useful, then when I first review it.

You might not have overlooked the legend. It might not have been there if you were using Firefox. I fixed a small problem yesterday that caused the legend to not appear in Firefox.

Thought about putting the legend on top of the map, but it makes the whole page looks sort of funny.

Rich