Video demonstrations of the portal
Video 1: Purpose and navigation of the
Video 2: Instructions for selecting
sites and downloading data
Video 3: Information on data downloaded
from the portal
Data provided in the portal
The sediment portal displays the location of sites in
which discrete and (or) daily suspended sediment data have
been collected in the United States. The U.S. Geological
Survey National Water Information System (NWIS) is the
original source for all suspended-sediment data provided in
the portal. Daily suspended-sediment data are retrieved
directly from NWIS; discrete suspended-sediment were
retrieved from NWIS in July 2017 and have been screened to
only those data thought to best represent particular
sampling sites and to sites with data potentially adequate
to compare among sites or compute loads.
USGS mean daily,
time-weighted suspended-sediment concentration (USGS
parameter code 80154), suspended-sediment load (USGS
parameter code 80155), and streamflow data (USGS parameter
code 00060) are retrieved directly from the U.S. Geological
Survey National Water Information System (NWIS).
Daily-record sediment data are daily mean estimates of
suspended-sediment concentration and (or) load, and are
computed at sites in which suspended-sediment concentration
samples are collected approximately daily or more
frequently. It is important to note that these daily
computations can be moderately to highly dependent on human
interpretation of the relation between streamflow and
sediment transport. Daily streamflow,
suspended-sediment and other water quality data from NWIS
can be found at
Daily sediment data field abbreviations,
definitions, and units provided by the portal can be found
Table 3 in the User Manual.
Note that unlike
discrete data, different daily sites are separated by
site-specific header information which may redefine column
Discrete suspended-sediment data
periodically-collected suspended-sediment data were
retrieved from NWIS in July of 2017. These data were
screened and augmented with available daily and
instantaneous streamflow information before being uploaded
to the sediment portal. Data were screened from
the sediment portal if:
- They were quality control samples, lake or reservoir
samples, and or were samples thought not to represent the
width of the stream cross-section.
- They were collected at sites not colocated with (or
verfied to be adjacent to) a daily streamflow
More specifics on the
methods used to screen and augment discrete
suspended-sediment data can be found in the sediment portal
user guide and in
Data Report 776. Discrete sediment data field
abbreviations, definitions, and units can be found in
Table 2 in the User Manual.
Note that prior to the July 2017 update only sites
with 15 or more discrete suspended-sediment samples were
able to be viewed and downloaded. The July 2017
update removed that restriction.
For information on
quality assurance tests of the accuracy and reliability
of discrete, U.S. Geological Survey suspended-sediment
analyses, please visit the USGS
Laboratory Quality Assurance Project
Viewing the portal
The sediment portal is best viewed in Google Chrome,
Mozilla Firefox, or Internet Explorer version 8 or newer.
The portal also works
in Safari, but testing has been limited and bugs may
A legend on the lower
right-hand side of the map indicates which sites have
discrete (blue) and daily (red) suspended-sediment data.
The size of each dot is proportional to the number of
discrete samples or length of daily record. To
minimize the site legend, click on the blue "Site Legend"
The size of the map and the
filters do not adjust automatically to the screen size of
you monitor. To adjust the portal to the desired
size, hold the control key and use the mouse to scroll
forward or backward to increase or decrease the size of the
map and data filters. Alternatively, if you are using
google chrome, you can adjust using the zoom option located
under the "Customize and control google chrome" option
located to the right part the address bar.
To zoom in on (or out from)
a portion of the map, either (1) double click on the area
of interest, (2) use the mouse to scroll or (3) use the
zoom bar located on the left-hand side of the map. The "+"
and "-" keys located at the top and bottom of the bar can
be used to zoom in or out one level (respectively).
The "-" symbol located on the bar indicates the
current zoom level. Users can click on a specific
zoom level, use the "+" or "-" keys, or use the mouse
scroll bar to zoom in or out on the map. To pan the
map, users can either left click on the mouse and pull the
map to the right or left or use the arrow keys located
above the zoom bar.
inspect a data point
Selected data attributes
can be inspected by left-clicking on single or groups of
dots that represent suspended-sediment sampling sites.
Upon left-clicking a
sampling site, a table appears that shows the station
name, the USGS streamgage identifier, drainage area in
square miles, the period of discrete sampling and/or
daily record (depending upon the site type), the number
of discrete samples, and the number of years in which
daily data are available. Click again on the map to
make the site inspection table to disappear.
use/change base layers and overlays
layers are available to help place sediment sampling
sites in context with spatial boundaries (political,
environmental, or basin boundaries) and landscape
characteristics. A full list of backgrounds is
listed open opening the portal; this list can be
minimized by clicking on the "+" tab located on the
upper-right hand corner blue overlay box. Background
layers are characterized as base layers and overlays.
layer showing selected political boundaries and
topography as well as a world image layer
use for the contiguous U.S. is from the 2006 National
Land Cover Database (NLCD). The 2006 NLCD did not
include Alaska (AK), Hawaii (HI), and Puerto Rico (PR),
so the layer has been appended with 2001 NLCD data for
these regions. Upon viewing the NLCD, a blue
"NLCD Legend" box will appear on the lower-right hand
side of the mapper. Click on this box to view the
legend, click on it again to minimize the legend.
The original dataset can be accessed via
Additional overlays include the
National Hydrography Dataset (NHD)
version 2 flow lines,
hydrologic unit code eight watersheds
U.S. Environmental Protection Agency
Level 2 Ecoregions (Ecoregion Level 2),
NHD-referenced locations of the
National Inventory of Dams, and USGS streamgage
basin boundaries (multiple sources, see section below
regarding Gage Basin ID filters). Ecoregion,
HUC and basin boundary layers will narrow as filters
are applied. See sections describing filters in
the user guide for more information.
How to filter data
Data filters are
designed to allow users to identify and get data for
sites of interest. Daily and discrete sediment sampling
sites can be filtered using available information on
geospatial boundaries, data characteristics, and
sampling site characteristics. Filters can to be
used to progressively narrow the population of sediment
sampling sites. For example if a data filter is
applied to limit sites to those with 0-50% agricultural
land use and by 0-25% urban land use, only those sites
are returned with both 0-50% agricultural and 0-25% urban
land use. The tab key or a left-mouse click can be
used to enter data in a particular filter. To apply a
filter, click the "Apply Filter" button located on the
top-right of the map or press the "enter" key on your
keyboard. To reset applied filters, click the
"Clear Filter" button located on the top-right of the
return the portal to the initial, default view, click the
refresh button on your browser.
types of data are available to download, (1) site
characteristics, (2) daily data, and (3) discrete data.
To download data, first use filters to identify sites of
interest (or apply no filters to download the entire
dataset) and then click the "Download Data" button
located on the top-right hand side of the portal.
Once the "Download Data" button is clicked, a pop-up
screen will appear that lets the user choose which data to
download, the format of the data, and how the data will be
delivered. The user is given the option to download
daily flow and sediment data from the U.S. Geological
Survey National Water Information System (NWIS) and (or)
discrete sediment and related data from the sediment
portal. Information on sampling site characteristics
is provided with either of these data downloads by default.
If users select to download discrete sediment data,
an option is provided to "Include Daily Flow" box.
Selection of this box will add the daily flow time
series from the discrete suspended-sediment data to the
daily data file (meaning that the "Daily Flow and Sediment
Data" box must also be checked). A time series
of daily flow data is provided along with daily sediment
data by default.
Additionally, if users desire only information on
sampling site characteristics, they should pick one (or
both) of the daily or discrete sample data and select the
box labeled "Site Attribute Information Only". If
this checkbox is not selected, users will get both the
sample and site characteristic data.
Data can be downloaded in .csv or .tsv format by
selecting from the drop down menu next to the “File
Format” button. Users can also have data sent
directly to their email by placing an email address in the
"Email Address" box. This is especially useful when
large numbers of data/sites are selected for download.
If no email address is entered, data will be
downloaded directly through the web browser. For more
information on any of these options, hover over the "?"
located to the right of each option.
A complete list of fields, field abbreviations, units,
and data sources of site characteristic data can be
accessed via this
link. Daily data are a daily time
series of mean daily streamflow, mean daily
suspended-sediment concentration, and mean daily
suspended-sediment data; a complete list of fields, field
abbreviations, and of daily sediment data can be accessed
link. Discrete data represent
periodically collected suspended-sediment and associated
data; complete list of fields, field abbreviations,
and of discrete sediment data can be accessed via this
USGS Data Report 776
More information on methods used to produce the sediment
portal can be found in
Data Report 776 or in the
Sediment Portal User Manual.