This is the first in a series of three videos describing the purpose and functionality of
the USGS sediment data portal.
This first video focuses on the purpose of the portal, and provides a brief introduction
on the navigation of the portal.
To get to the portal, go to cida.usgs.gov/sediment.
A report which describes the data contained within the portal and gives examples as to
its use can be accessed at pubs.usgs.gov/ds/776.
The portal has been designed to help folks interested
interpreting suspended-sediment data better view, select, and download the data they need.
Three types of data are provided in the portal: The first are discrete suspended-sediment
data.
These data are results from samples collected from streams or rivers a known date and time.
More than 600,000 of these samples are available within the portal.
The second are mean daily estimates of suspended-sediment concentration and/or load.
More than 10,000 years of this data are available within the portal.
The third are information on sampling site characteristics of discrete and/or daily suspended
sampling sites.
These data include information on the site itself, such as site name, latitude/longitude,
and information on streamflow characteristics, but also characteristics of the upstream drainage,
such as total drainage area, average precipitation, soil characteristics, or land use.
There are some key features of the portal that we think will make it useful to folks
trying to obtain and interpret suspended-sediment data
The first is that suspended-sediment sampling sites and data are represented through a map
interface that has a variety of tools to help select sites of interest.
The second are that the only sites/data provided in the portal are those that were collected
with the intention of representing the entire cross-section of stream and river sites.
Thus some data present in the USGS National water information system database are not
included in the portal, such as quality control samples, samples collected at lakes, or samples
collected at specific points in the stream cross-section.
Also excluded are any sites with less than 15 samples.
Another feature has to do with pairing streamflow data with discrete suspended-sediment samples.
Currently, many existing USGS discrete samples don't have corresponding information on streamflow
conditions.
For the portal, if streamflow data were not present for a particular sample, but were
available as a daily or instantaneous time series, we matched the time-series data to
the discrete sample on the same date or date/time.
Lastly, the portal provides easy access to available data related to suspended-sediment,
both for discrete samples, such as information on sediment grain size, water temperature,
turbidity, and other data, as well as for sampling site characteristics.
Now let's go to a brief demonstration of the navigation of the portal.
The sediment portal can be access by typing in cida.usgs.gov/sediment.
When you first get on to the portal site, a splash screen pops up that shows a link
to a quick start guide and provides some brief instructions as to how to navigate the site.
Also provided on the splash screen are a couple of paragraphs, the first paragraph explains
the purpose of the site, that all of the discrete and daily suspended-sediment data were originally
obtained from the USGS National Water Information System, otherwise known as NWIS, and that
all data present within NWIS may not be in the portal.
Also provided is a link to a user guide, which is a more comprehensive version of the quick
start guide, and the second paragraph is a disclaimer.
Click OK to get the splash screen to drop off.
When you first get on the site, sometimes you will encounter a situation where the sediment
mapper and filtering options are relatively small or large for your browser window.
To correct his, just go up to settings in your web browser, whether it is google chrome
as shown here, or whether it is firefox or internet explorer and change the zoom settings.
We'll zoom to 100%; that looks a little better.
Another thing I wanted to note are that the preferred browsers for the sediment portal
are google chrome, firefox, or internet explorer version 8 or newer.
So when you look at the portal, you will see there are two main parts.
First you can see a map interface which shows blue and red dots.
The blue dots correspond to discrete suspended-sediment sampling sites, the red dots correspond to
daily suspended sediment sampling sites.
The size of the dots correspond to the amount of data available.
Over here is a legend which you can pop on or off, that indicates which dots are which,
over here to the left are the zoom bar and panning tools, and over here to the right
of the mapper are various data overlays.
The other parts of the website are the filtering options to the right, once you enter a filter
you can apply the filter, clear previously applied filters, or download the data you
selected.
Lastly over here is a help button which allows users to select a quick start or user guide.
If you are having problems with the site, there is a link over here to Sediment portal
help, which allows you email us with any of the problems you are experiencing.
In this first video we will explain how to navigate the portal and the various data overlays.
First, on the map, if you want information on sampling sites just click on one or groups
of these dots on the map.
Any of the dots I click on will display a table using a site ID tool.
A table will pop up that shows the site name, USGS streamgage ID, upstream drainage area,
and the period of record whether it is discrete or daily.
The sites selected were discrete, if you selected a red dot you would get corresponding information
on the time period and length of the daily record.
To get this pop up to go away, click somewhere where there aren't any dots, we'll click out
in the ocean.
To zoom in or out you can use the zoom bar located to the left of the mapper.
I'll click two levels out, what you'll notice is that the data reload.
So depending upon your connection speed or the traffic on the site, the data may reload
at different speeds.
In this case it happened relatively fast.
What you can also see here is that although the default zoom is the conterminous United
States, we also have data in Puerto Rico, Alaska, Hawaii, and Guam.
Let's zoom back in using the zoom bar.
So in addition to being able to zoom with the zoom bar, you can also double click to
zoom in.
So I'll click on Colorado, and I'll keep double clicking to zoom in further.
So this is a good way to zoom specifically to the area you want using your mouse.
You can see the data continue to reload, at some point in time you may zoom in so far
that you don't know where you are and you want to get back to the default zoom.
In that case all you have to do is go back up and hit fresh on your browser and you will
get the view of the conterminous United States with the splash screen.
The other ways you can zoom in or around data are to pan using these arrows to the right,
left, up, or down.
You can also left click and drag the map where ever you want.
That is basically the overview of how to navigate the portal map.
The last thing I want to talk about in this video are the various data overlays.
We have some options for different base layers and overlays behind the data.
This green and white map displayed behind the sites now is called the topographic layer.
You can also look at a world image layer.
Those are the base layer options.
Of the various data overlays we have, the first one is the national land cover data
base, labeled as NLCD, this is land use and landscape information from 2006, you'll see
that there are different colors displaying behind the sampling sites.
Go down here and click on the NLCD legend to see what those colors correspond to.
You'll see that there are various levels of development intensity, forest, scrub and shrub
land, grassland, pasture, crops, etc.
Just click back on the NLCD legend to get it to go off.
You also have option to highlight states, or counties within those states.
You have the option of showing hydrologic unit code 8 watersheds, you have the option
of looking at national hydrography data set flowlines, so you ca see the location of stream
and river with respect to the sediment sampling sites.
Note that at this current zoom level it is a relatively coarse stream network, as you
zoom in farther and farther you will display smaller and smaller streams.
You can look at EPA level 2 ecoregions, and you can look at the basin boundaries for any
of the sediment sampling sites.
You also have the option of looking at only discrete or daily sampling sites.
The last layer that is available is the U.S. Army Corps of Engineers dataset that shows
the location of dams in the United States called the national inventory of dams.
These are denoted by the brown colored triangles.
Some of these layers, including the USGS basin boundaries, ecoregions, HUCs, and states,
will filter as you apply boundary filters.
So if you pick a specific basin boundary, only that specific basin boundary will show
up, the same thing is true of the HUCs and the ecoregions.
That concludes this first introductory video showing the purpose of the portal and the
map interface.
Thanks for attending this introduction to the USGS Sediment Data Portal.
The next video will show how to select and download data for sites of interest using
the various filtering tools provided by the portal.