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 … Continue reading
Recently, an extensive collection of Lidar data of England and Wales was made available by Environment agency of England and Natural Resources Wales respectively. At 2 meters resolution (cell size), the lidar derived DTM (bare earth) covers nearly three quarters (~70%) of England and Wales. The … Continue reading
Hey check out these code samples from the imagery team that were presented at the 2015 Developers Summit! You can do stuff like: Model avalanche risk Model flood zones Display flow data using vectors based on magnitude and direction, or … Continue reading
By Denny Rivas. Center for Research in Water Resources. The University of Texas at Austin. Consider you are asked to undertake research on hydrology, in which you have to propose new methodologies using scarce available data, and look for novel … Continue reading
By Patrick Bergeron, postdoctoral fellow, INSPQ and Univerisité de Sherbrooke, Canada. Temporal floodplain delineation is an important aspect of many urban and environmental management plans. Water height data, measured under bridges or at gauge stations, are common and usually free. … Continue reading
by Michael Dangermond, Senior Digital Cartographer, Esri
The Soil Hydrology of the United States Web Map Application brings some of the most important hydrologic soil properties together in one map. Find hydrologic group codes for hydrologic and hydraulic models. Find hydric soil information to determine wetland land classification. Find depth to the water table for groundwater analysis and well drilling operations.
by Laurie Williams, Senior Planner/Watershed GIS, County of Marin, CA
The Department of Public Works of Marin County, CA (just north of San Francisco, CA) launched a watershed program to integrate flood protection, stream and wetland habitat restoration activities, fish passage, and water quality improvements. Instead of looking at flooding issues on a site by site basis, we solve flooding problems at a watershed scale, and employ solutions such as habitat restoration to reduce flood risks.
From the outset, we decided to base our stakeholder outreach, collection of scientific studies and technical reports, and dissemination of information from the Marin County Watershed Program website (http://www.marinwatersheds.org) in order to save paper resources, be more user-friendly, support community outreach and more efficiently advertise our updates than is possible with more traditional printed reports and documents.
Our website is the major repository of meeting notices, posted reports, and maps. Our website designer, Athena Design, chose a color palette to enhance and reflect the colors of nature: the blues of water, the greens of plants, and browns for earth tones; orange splashes complement the dominant blue. We use the palette extensively in producing the watershed maps, as well as for printed materials and PowerPoint presentations for a unified design.
by Paul Robinson, Water Resources Team Leader
Imagine being able to have an idea of where flooding issues are at the outset of a project. What if we could squeeze government dollars a bit harder and quickly map flood risk for a whole nation?
Making good use of available GIS data and new tools in the armory of our profession are rapid flood inundation models like Halcrow’s ISIS-FAST. The tool provides a quick assessment of flooding using simplified hydraulic principles to provide results up to 1000 times quicker when compared to other tools and methods available for flood inundation simulations – i.e. providing results in minutes as opposed to hours or days.
ISIS-FAST works by first identifying depressions on the floodplain before routing water through these depressions. Water depths in the depressions are determined by: volume of water flowing into that depression; level at which water can spill into neighboring depressions; and water level in neighboring depressions. ISIS FAST represents connectivity and volume filling effects on the floodplain, without having to represent detailed hydraulics.
This month we released the Flood Planning Map, the first in a series of maps and apps to help emergency managers and community leaders prepare for flooding events.
The Flood Planning Map provides flood planners with a set of tools and workflows to prepare for seasonal river flooding. These tools and workflows are based on real-world examples that have been used during previous flood events in the upper Midwest. Seasonal river flood planning is typically conducted weeks or months in advance of predicted crest in each community. This advance notice gives community leaders time to plan for securing assets, protecting infrastructure, or evacuating citizens within the impact area.
The first version of the Flood Planning Map provides the ability to do the following:
- Determine the flood impact area based on predicted flood levels.
- Identify critical infrastructure, facilities, and citizens that could be impacted.
- Create budgetary cost estimates for temporary levees.
- Share the results with others who will execute the flood plan.