Showing posts with label hydrology. Show all posts
Showing posts with label hydrology. Show all posts

Wednesday, October 1, 2014

Draining California

National Geographic has an article about the California drought in the October issue called When the Snows Fail. The magazine comes with a fantastic pull-out map showing the natural and manipulated ways that water flows out of the Sierra Nevada into the Central Valley, the heartland of US agriculture.
#
The printed map sprawls across several flaps and shows a broad view of the entire regional water system in a way that can't possibly (or legally) be shown here. The image above gives an idea of much of what is shown on the map including aqueducts  (light blue lines), agricultural areas in green, dams, reservoirs (with information about  percentage above or below capacity) and various other bits of textual information.

Their web site has an interactive graphic that captures some of the map's information. Click on the second tab for the graphic, the first one is the article. The graphics do a nice job of showing the flow of water from the headwaters of the Rubicon River, near Lake Tahoe, into reservoirs, lakes, the American and then Sacramento Rivers. Three years of drought have left dry shorelines, lower volumes of surface water and increased use of wells causing subsidence of the land. 
http://www.nationalgeographic.com/west-snow-fail/
The interactive web graphics are very well done, but also are a good illustration of how computer images still cannot provide the awe inspired by a large paper map. I highly recommend getting a hold of the magazine and taking a look at the full "centerfold."

Thursday, March 6, 2008

Map of the Week 115-The Oak Park Continental Divide

Continental Divides usually bring up images of snowy mountain peaks but sometimes the mountains look like this:


Yes the suburban folks of Oak Park, Chicagoland, Illinois have their own continental divide and they're proud of it! They even have a web page to showcase it. The map below is proof for skeptics - stand at the corner of Division and Elmwood with a cup of water and watch some of it flow to the Gulf of Mexico while the rest goes to the Atlantic via the St. Lawrence Seaway.


<- This is a detailed map showing the approximate line of the divide. My guess is that the storm drainage system adds a layer of complication, making the map approximate at best.
The map above can be further subdivided - if you do this enough times you will eventually find your own local continental divide that you can brag about!