Measurement

It is not an easy task to keep a swimming pool so clear and clean. If you just set a pan of water outdoors in the middle of summer, you'll see that it ends up containing gunk very quickly. People have to resort to both chemical and physical means to keep...
Data are offered in both compressed ARC workspaces and compressed SDTS transfer format.  
A digital orthophoto quadrangle (DOQ) is a computer-generated image of an aerial photograph in which displacements caused by terrain relief and camera tilts have been removed. It combines the image characteristics of a photograph with the geometric...
Birds: Information on Salton Sea bird die-offs can be found through the USGS National Wildlife Health Center Web site.   Information has been issued by the center through their Quarterly Wildlife Mortality Report.Fish: There are several species of...
You can view a national map of hardness in surface water at water hardness map. Hardness data (reflecting mostly calcium, plus a little magnesium) for individual drinking-water suppliers can be found at this link EPA Office of Ground Water and Drinking...
Yes, it is not unusual for salt marshes to experience dieback in small patches in some years. However, these areas are usually less than an acre or so in size and generally regenerate the next year or over the next several years. Smooth cordgrass marshes...
Most survey marks were set by the US Coast & Geodetic Survey (now called the “National Geodetic Survey”) and information for those marks is availble on the web. For further assistance call 301-713-3242 or                             e-mail  ...
Safe water means water that will not harm you if you come in contact with it. The most common use of this term applies to drinking water, but it could also apply to water for swimming or other uses. To be safe, the water must have sufficiently low...
Information on pesticides and herbicides and on nutrients is available from the USGS National Water-Quality Assessment Program 
The salinity of Great Salt Lake is measured by taking specific gravity and temperature measurements and comparing them to standardized values reported in a table. Specific gravity is measured in the field by testing a water sample with a device very...