|May 17, 2013||Posted by karmadsen under blog, GIS, Groundwater Modeling, Groundwater Modeling Software, GroundwaterGo, Open Source|
I have published a short report providing a better explanation and theoretical background on the map the water-table algorithm. The report, An Algorithm for Estimating the Topography of the Water-Table, can be read and downloaded here.
|May 16, 2013||Posted by karmadsen under blog, Groundwater Modeling, Groundwater Modeling Software, MODFLOW, Programming|
Scientists throughout the world are continually developing new packages for MODFLOW to expand the functionality of the code. In 2010, graduate student Wesley Henson presented his new packages, MODFLOW-PSZ, at several hydrology conferences.
In the 2010 Proceedings of the Student World Water Forum, he wrote:
“A perched aquifer often develops in the soil zone during periods of heavy rainfall, delivering interflow to channels in a watershed. The soil zone has been described as the upper most region of the vadose zone where plant and soil processes enhance storage and permeability, providing a fast pathway for water and solutes to streams. The soil zone connects the watershed surface to the deeper unsaturated, and saturated zones. Modeling of soil zone processes has been used to gain understanding of watershed hydrologic processes. Currently MODFLOW-2005 does not simulate dynamic near-surface hydrologic processes such as, infiltration, hortonian runoff, dunnian runoff, and return flow. The Perched Soil-Zone package (PSZ) for MODFLOW-2005 is being developed to address these major components of hillslope hydrology for simulating watershed processes in the context of basin-scale groundwater flow modeling.”
In his 2011 dissertation, Henson compared a new version of this package, the MODFLOW Soil-Zone Processes Package, with Richard’s Equation for infiltration. His research indicated that the MODFLOW-SZP was more efficient that Richard’s Equation in numerical modeling for his test cases. Henson’s dissertation, A Model for Simulating Soil-Zone Processes at the Regional Scale, is available for purchase from Amazon.com.
|May 14, 2013||Posted by karmadsen under blog, Conferences/Events, Groundwater Modeling, Groundwater Modeling Software, MODFLOW|
On May 22nd, Environmental Simulations Incorporated will be holding free seminars called “Introducing MODFLOW-USG for Unstructured Grids in Groundwater Vistas.”
The new Groundwater Vistas 6 supports MODFLOW-USG, a code that frees the MODFLOW numerical process from the need for a rectangular grid. This allows the user to develop complex shapes within the grid, such as trangular meshes around wells.
|May 13, 2013||Posted by karmadsen under blog, Groundwater Modeling, Groundwater Modeling Software, GroundwaterGo, MODFLOW|
I have added USGS NED rasters to model output view in Ginger MODFLOW to provide better context for models.
|May 12, 2013||Posted by karmadsen under blog, Climate Change, Videos|
- On May 9th, NOAA‘s Mauna Loa Observatory took a history-making atmospheric carbon dioxide measurement: 400 parts per million. Carbon dioxide measurements have been collected at the station since 1958, making it the longest measurement record in the world and the current rate of carbon increase is 100 times greater than expected during interglacial periods.
- In reporting on the history measurement, the New York Times explained that the carbon dioxide concentration in earth’s atmosphere hasn’t been so high in at least three million years. Based on glacial ice records, scientists estimate that carbon dioxide has fluctuated between 180 and 280 ppm over the last 800,000 years.
- What does climate change mean right now? CNN has published several videos on some of the immediate affects of climate change. One of these changes, higher pollen count, is making me miserable at the moment. The average pollen count is expected to double in the next 30 years.
|May 10, 2013||Posted by karmadsen under blog, MODFLOW, Programming|
As a non-computer scientist, I used to accept that Fortran was wonky when CS people expressed their dislike of Fortran to me. Hey, it is old. It must be wonky, right? So I was actually somewhat surprised to find that Fortran was just dandy when I finally got around to looking at the actual code. I understand that a lot of people prefer more modern programming language, but computer logic is computer logic. I looked at some programming forums to figure out where this negativity is coming from.
Commenter Eric_t on bitbucket.org wrote: “In online programming discussions, Fortran seems to have gotten an undeserved bad reputation. Most of the time, comments of the language are based on the Fortran 77 edition of the language, and fail to take into account that the language has seen four major revisions since then.” Jon Be, commenter on the computer-programming-forum.com, suggested that people who program in Fortran are often not computer scientists, which means their code looks messy and disorganized to computer scientists. I suppose I may be guilty of that myself.
A Michigan State University page explains: “Lower level languages such as Fortran and C have been around for a long time and usually get a bad reputation. Newer is better, right? Not always! There are some decisive advantages to lower level languages. In particular, they’re blazingly fast for numerical work.
As the video below explains, Fortran is a language for scientists, engineers, and mathematicians. Modern languages are often put to very different uses, such as web design. Computer scientists would prefer to use the right tool for their particular job, and, unless the job involves solving complex mathematical problems, the right tool generally isn’t Fortran. But for numerical modelers, Fortran is the best, because it is the fastest.
|May 9, 2013||Posted by karmadsen under blog, GroundwaterGo, MODFLOW, Visualization|
Just to let people know, I am working to improve the visuals and user experience of Ginger MODFLOW. The interface is pretty confusing at the moment (and it doesn’t look great either).
So far, I have improved the color display to show groundwater heads in better detail, and will continue to improve the visuals this weekend.
|May 7, 2013||Posted by karmadsen under blog, Conferences/Events|
- The National Academies will be holding a series of meetings on increasing public assess to federally-supported research data and publication (via EarthCube). The meetings will be held May 14-15 and May 16-17 at the National Academy of Sciences in Washington, DC.
- The National Groundwater Association will be holding a three-day course called, “Principles of Groundwater: Flow, Transport, and Remediation.” This introductory course will be held in Columbus, OH August 12-14. Register here.
|May 5, 2013||Posted by karmadsen under blog, Drinking Water, Drought, Videos|
Children were especially at risk during the the 2011 East Africa drought.