Category: Local Government
In countries like the United States and Germany, federal agencies keep careful watch on the nation’s rivers, and disseminate their observations to the public. But in developing nations, many of the world’s major rivers remain un-gauged, despite the millions of people whose lives depend on them. The Dartmouth Flood Observatory hopes to help solve this problem with a concept they call “satellite gauging sites,” which makes it possible to monitor the flowrate of rivers using freely available satellite data, without the need to build or maintain expensive infrastructure.
They key to this method is the microwave sensors carried aboard satellites like AMSR, TRMM, and GPM. As the amount of water on the landscape increases, emissions in the microwave spectrum decrease – a clear signal that can be used to track flowrate. Microwaves are unaffected by cloud, but absorbed by liquid water, which means that Flood Observatory scientists can monitor river conditions even when the ground is visibly obscured by weather.
The numerical estimates are much less accurate than ground-based gauging, of course, but still extremely valuable. As a relative estimate of how the flowrate is changing over time, they can be used to track droughts and floods, and to analyze long-term changes in the flow regime.
In order to make them more easily available to the GIS community, Esri has added these satellite gauging sites to the Live Stream Gauge map. When you click on one, it displays an estimate of today’s average flowrate, a description of the status (e.g. low flow, moderate flood, major flood), and a graph showing the time series. There is also a link to the station page, where you can get monthly and annual flow estimates, as well as some information about the calibration and accuracy of that particular site.
This latest update also included new contributions from England’s Environment Agency, the State of Nebraska, the State of Oregon, and the Iowa Flood Center – over 3000 new gauges in total – so if you haven’t checked it out in a while, now is a great time to take another look. For those of you who have been using this map, please let us know your thoughts about it in the comments. Thank you to all our stream gauge contributors!
Earlier this week we updated our Vector Basemap (beta) tiles with additional community content, newer commercial data, and improved map appearance for parts of the world. This is the ninth Vector Basemap update since our Beta 2 release in mid-May. … Continue reading
[Source: Survey123 for ArcGIS Blog in GeoNet] Around 11:30 A.M. on November 7, 1492, a young boy saw a large stone plummet from the sky and land in a wheat field near the town of Ensisheim in Alsace, France. This … Continue reading
Since our release of the NEW Open Data Sites into beta just before the 2016 User Conference, the open data team has been very busy adding more functionality you have requested into the new sites. Let’s take a quick look … Continue reading
Our user community has provided updates to the World Topographic Map! Contributing to Esri Community Maps is easy! This basemap release includes new Community Map contributions to the World Topographic Map. Areas with new and updated content include the country of Thailand and … Continue reading
We have updated the World Imagery basemap with more recent imagery from DigitalGlobe and several organizations from the GIS user community. This latest update features DigitalGlobe imagery for large parts of Western Europe, as shown below. This is the third … Continue reading
[Source: Survey123 for ArcGIS Blog in GeoNet] A barcode is an optical machine-readable representation of data. A lot of things around us have barcodes. You will find them in virtually any packaged item you buy, in the back cover of … Continue reading
Well, you missed a good GeoDev Meetup this week in D.C. The GeoDev team headed out from New York and arrived in D.C. on Tuesday, October 11th. We had a special treat this time around in that the Esri R&D … Continue reading
Esri is increasing the pace of releases of ArcGIS for AutoCAD by creating smaller scope releases. This is one of those incremental releases. Be sure to download the newest version of ArcGIS for AutoCAD 355 now, which is available here.
This new release includes updated support for AutoCAD versions 2013-2017 in nine different languages. New in this release is a command to generate local feature classes from all the populated layers in your drawing. This new command is good for creating new local feature classes from well-structured drawings that you intend to share with ArcGIS desktop users, or that you want to add tabular attributes to within AutoCAD.
This important release fixes a bug when connecting to secure services on ArcGIS 10.3.x and higher servers. This release will also warn you when you connect to feature services on 10.3.1 servers containing unsupported date fields. (This issue with feature service date fields in ArcGIS Server was fixed in ArcGIS Server 10.4), but in case you are using 10.3.1 servers with ArcGIS for AutoCAD you will be warned that you cannot synchronize services when a date field is present in feature services on those servers. Check out this brief video for an overview of what’s new in ArcGIS for AutoCAD 355.
We continue to improve the World Imagery basemap with updates from DigitalGlobe and our GIS user community. This update features new and improved high-resolution imagery for areas covering most of Brazil, Saudi Arabia, and Denmark, parts of New Zealand and … Continue reading