English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The National Stream Quality Accounting Network (NASQAN) was established by the U.S. Geological Survey to provide a nationally uniform basis for continuously assessing the quality of United States rivers. Stations are generally at the downstream end of hydrologic accounting units in order to measure the quantity and quality of water flowing from the units. The 1976 water year is the second year of operation of the network that represents essentially all of the accounting units and thereby describes the water-quality of the entire country. Data are available on a large number of water-quality constituents measured at 345 stations during the 1976 water year. Temperature data (usually continuous or daily measurements) from NASQAN stations were fitted to a first order harmonic equation, and the parameters for the harmonic function are reported for each station. Mean temperatures generally range from 5°-10°C in the North to more than 20°C along the southern border of the continental United States, in Hawaii, and in Puerto Rico; mean temperatures were less than 10°C at 62 stations and greater than 24°C at only 7 stations. Amplitudes of the temperature curves are greatest (greater than 12°C) for the streams at midlatitudes and in the Great and Central Plains, and are smallest for the subtropical and cold-climate streams. Considering chemical and biological characteristics of United States streams as described by NASQAN data, water quality is best (by many standards) in the Northeast, Southeast, and Northwest. These waters are generally low in dissolved solids and minor chemical constituents, are generally soft (except in Florida), and carry relatively small amounts of suspended sediment. These conditions mainly reflect the geology of the areas and the relatively large amounts of precipitation. However, many of these waters show the effects of pollution and carry moderate or high concentrations of nutrients and have correspondingly high populations of attached and floating plants. High counts of indicator bacteria also show signs of local pollution, particularly in areas of the country with large human or animal populations or both. Streams in the mid-continent area generally contain higher concentrations of minor elements than other areas of the country. Most streams in the Midcontinent and Southwest areas reflect the arid or semiarid climate, erodible soils, and agricultural activities. They are characterized by moderate to high levels of dissolved major and minor constituents, suspended sediment, major nutrients, and biota (floating and attached aquatic plants and indicator bacteria). In addition, pesticide residues were found most often and concentrations were highest in stream water and bottom sediments found in these areas.

Quality of rivers of the United States, 1975 water year; based on the National Stream Quality Accounting Network (NASQAN)