Tag Archive: GIS


In my search for Open Source GIS programs, I stumbled across something called OSGeo Live, which was considered a geospatial package tool, mentioned in a website.  Not ever hearing about anything like this before, I decided to research what it is since I am always looking for new geospatial tools and softwares to experiment with for GIS purposes.   After searching through the web, I came across OSGeo Live’s website (http://live.osgeo.org/en/index.html).  It seemed fascinating that I could use a wide variety of open source geospatial software without installing anything (A list installed softwares can be found at http://live.osgeo.org/en/overview/overview.html).  So I thought to myself, “Let’s give it a try!”

Once I downloaded the application and extracted it (which is about 2.7GB) it had a file extension I never heard of before <*.7z> and that my computer did not recognize.  This ended up needing to be open in a WinZip like application called 7zip.  Once I unzipped this file download, another file extension popped up that my computer did not recognize, nor did I recognize it: <*.vmdk>  –  So again, I was on a search to figure out this file extension since I was walking into a new world of applications, softwares, file extensions, that I have never dealt with before.  After this research, I came across what it was – VMware Virtual Disk File.  In order to open this I needed a Virtual Desktop.  I searched in Google’s search engine “what is the best virtual machine application” and I came across a website that listed VirtualBox (https://www.virtualbox.org/) as the number one choice with a description from http://lifehacker.com/5714966/five-best-virtual-machine-applications as follows:

“VirtualBox has a loyal following thanks to a combination of a free-as-in-beer price tag, cross-platform support, and a huge number of features that make running and maintaining virtual machines a breeze. Virtual machine descriptions and parameters are stored entirely in plain-text XML files for easy portability and easy folder sharing. Its “Guest Additions” feature, available for Windows, Linux, and Solaris virtual machines, makes VirtualBox user friendly, allowing you to install software on the virtual machine that grants extra privileges to the host machine for tasks like sharing files, sharing drives and peripherals, and more.”

Then follows the steps to get it started: http://live.osgeo.org/en/quickstart/virtualization_quickstart.html

Once inside of the virtual machine for OS Geo Live, perform the following functions before getting started in any of the programs:

  1. Click on Applications/System/Terminal ;
  2. Type sudo su to become a super-user
  3. Update your APT database with sudo apt-get update, and typing your password, if requested;
  4. Install the latest security updates with sudo apt-get upgrade;
  5. Install required packages with sudo apt-get install build-essential module-assistant;
  6. Configure your system for building kernel modules by running sudo m-a prepare;
  7. Click on Install Guest Additions… from the Devices menu, then choose to browse the content of the CD when requested.
  8. type sudo apt-get install linux-headers-‘uname -r‘
  9. type cd /media/VBOXADDITIONS_4.2.6_82870/
  10. type sudo ./VBoxLinuxAdditions.run
  11. type mkdir <name of your shared drive folder>
  12. type sudo mount -t vboxsf -o uid=user,rw <name of your shared drive folder> /home/user/<name of your shared drive folder>

Another option for the a virtual machine is the free VMWare Player (http://www.vmware.com/products/player/?src=WWW_BestMatch_US#utm_source=WWW_BestMatch_US&utm_medium=src&utm_campaign=src-tagged-url).  The same aforementioned website provided the following description:

“VMware for desktop users comes in two primary flavors: VMware Player and VMware Workstation. VMware Player is a free solution aimed at casual users who need to create and run virtual machines but don’t need advanced enterprise-level solutions. VMware Workstation includes all the features of VMWare Player—easy virtual machine creation, hardware optimization, driver-less guest OS printing—and adds in the ability to clone machines, take multiple snapshots of the guest OS, and a replay changes made to the guest OS for testing software and recording the results within the virtual machine.”

I also came across another GIS virtual desktop called GISVM (Geographic Information System Virtual Machine) which can be founded at http://gisvm.com/- I will give this a try at a latter date and then compare the two GIS virtual desktops.

Case Study Proposal:

 
PROPSED TITLE:
The identification of 25 potential sites to construct cell phone towers around the Greater Boston Metropolitan Area
 
ABSTRACT 
This study will examine the potential for a design of a project in regards to a wireless phone company who is interested in expanding their communication network to receive better coverage in the Greater Boston Metropolitan area of the Commonwealth of Massachusetts.   The project will consist of sorting through many datasets available online via http://www.mass.gov/mgis/massgis.htmand then downloading key features that may assist in the creation of geodatabases.  Ultimately, this will align the various analyses of determining which datasets will reveal ideal locations for the new cell towers.  Furthermore, new developments have boosted the population in and around Boston creating a greater demand for communication technologies, especially as the networks are expanding into 4G standards.
 
MASS.GOV LAYERS
The following layers will establish a base foundation dataset in order to perform several different types of analyses.  Some of these datasets may be repetitive (i.e. some of the data will be downloaded for awareness) or may only be used as a reference and not in the actual analyses  (which are located immediately below).
 
BACKGROUND LAYERS:
 
 
 
 
RASTER LAYERS
Elevation
·         Shaded Relief (1:5,000)
 
VECTOR LAYERS
Census/Statistical Data
Ground Suitability Data
·         Impervious Surface (raster to vector conversion)
Conservation/Recreation (merge into one shapefile)
Infrastructure
Transportation
Other Facilities (merge into one shapefile)
Physical Resources
Topography
Water Features (Merge into one shapefile)
ADDITIONAL LAYERS
Additional layers can be found at http://wireless.fcc.gov/geographic/index.htm– it is important to understand the current cell tower infrastructure in identifying gaps in coverage or where they may lay in regards to more population density in one area over another.  Also, major thoroughfares need to have consistent connectivity for travelers as well as be able to handle the influx of users on a cellular network.  This site provides maps showing FCC licensing data, regulated towers, and market area boundaries.  These maps then need to be converted into a raster file and eventually digitize to extract the generated information on the map into vector files.  Another website I would extract data from would be www.cloudmade.com.  There are no guarantees on what type of data will be available, but cloudmade.com allows you to download various shapefiles of landmarks, infrastructure, and other user-generated data that has been uploaded to openstreetmaps.com.  Acquiring traffic data will also be of value for this project in order to identify high trafficked areas of cars along major thoroughfares.
 
METHODOLOGY
There are several types of analyses I would use within ArcGIS in order to conduct this project.  Proximity analysis is useful in several different ways.  First and foremost, in this project the geographic constraint is 25 miles outside of the Boston city limits.  I will create an extent polygon in order to clip out each of the attributes of my shapefiles that fall outside of this area.  This will allow me to use smaller datasets and not have to be concerned with highways and schools (including colleges and universities) outside of the constraint, among many other shapefiles’ attributes.   On the other hand, some of the features are not necessarily that important by themselves.  For example, there are various types of water features or conservation/recreation layers that do not need to be standalone files.  Merging these various datasets in order to eliminate unnecessary cluster is important so there is less data to work with.  The important factor as a result is that at least the water features and conservation layers are captured since building a cell tower is not an option within these locations.  Another type of proximity analysis is buffering.  In order to identify build zones, a 1 mile buffer must be conducted around the MassDOT Roads (attribute: highway) shapefile and then the lines must be dissolved in case several highways are in close proximity to one another.   In addition, buffering must be done with a radius of 1 mile around all schools.  Once the new shapefiles are generated as a result of the buffering tool, I will overlay each of the buffer files and delete from the highway buffer, wherever the school buffer file overlaps to minimize the amount of ideal locations.
 
Besides proximity analysis, other types of analyses will be useful in finding ideal locations for the new cell towers.  Towers need to be located in areas where population density is higher than normal to cater toward the influx of people utilizing the network.  As a result, a population density analysis must be conducted based from census data.  Elevation data can assist in terrain analysis in order to identify any hills or peaks above and beyond 250’ above sea level.  Once this area is identified, soil and hydrographic analysis will be conducted in order to determine the ground suitability for building the tower to ensure it is placed in a strong foundation.  Lastly, since cell towers need to be in a close proximity to other cell towers, the next type of analysis I will conduct is a Line of sight analysis to ensure the newly identified locations are within a certain distance from other towers and there are no vertical obstructions and to identify the potential cell coverage. 
 
CONCLUSION
The results of this project should determine what areas within the Greater Boston Metropolitan region are ideal in order to build new cellular towers.  The additional datasets from the FCC website will help to alleviate any overlapping towers in order to improve the communications network.  Geospatial data of the amount of users per cell towers in and around the ideal locations would probably improve this study.  Since urban and rural areas have different needs in regards to cell tower use, towers need to be located in ideal locations, but since cell towers are known to possibly cause health issues, towers must stand clear of schools and recreational areas.
 
LIMITATIONS
This most anticipated roadblock will be the accuracy of all of the data.  Not all the data in the files being used has been captured in the past year.  Therefore, some of the data may be missing components crucial to a full and complete analysis of identifying ideal locations.  Further research needs to be done to confirm the validity of all the data.  For example, have any schools closed down since the shapefiles were generated or have new school been built would be questions that need to be answered.   Also, an urban legend about cell towers is often told that they cause cancer and serious health risks.  Cellular technology is a relatively newer technology and the health community is unable to confirm this suspicion as of yet; however, the public still has some reservations about them being erected nearby to residential areas.  Lastly, the wireless company may have to pay rent for the location of the tower especially if it’s close to residential areas because of the depreciation of property that it will affect the neighborhoods the towers are being built around.

I came across the following site that has a wealth of free information on Geographic Information Systems'(GIS)-related information by Berry & Associates // Spatial Information Systems (BASIS).  Map Analysis is a great subject for anyone interested in analyzing maps especially through GIS. A link to the material is http://www.innovativegis.com/basis/

There are presentation slides in the "Online Books and Materials: Map Analysis Workshop Materials" by Joseph K. Berry that go over various topics in the workshops presented such as Introduction and Data Considerations, Spatial Analysis Techniques and Considerations, Spatial Statistics Techniques and Considerations, GIS Modeling Approachesand Considerations , among others.

There is also a free online book which can be downloaded that covers a wealth of topics such as Spatial Interpolation Procedures and Assessment, Where Is GIS Education?, Analyzing Accumulation Surfaces, Linking Data Space and Geographic Space, Analyzing Landscape Patterns, Applying Surface Analysis,  Human Dimensions of GIS, Overview of Spatial Analysis and Statistics, Spatial Data Mining in Geo-business and much more.
A link to the book can be found here: http://www.innovativegis.com/basis/mapanalysis/

Happy Reading!

Case Study Proposal:



PROPSED TITLE:
Population Growth in Prince William County, Virginia and its Implications on the Environment.
ABSTRACT 
This study will examine the continuous urban sprawl and suburban development in Prince William County, Virginia.  Prince William County is located in the region of Northern Virginia, which is a part of the Washington DC Metropolitan greater region.  Urban development disrupts hydrological and ecological systems, in addition to isolating and degrading local natural habitats.  Over the past few decades, Prince William County has transformed from a rural area with two main population centers, Manassas and Woodbridge, to a thriving society.  Today, these two population centers now are interconnected with a steady stream of roads and neighborhoods.  20 years ago, this area was quiet and had quite a lower population. In 20 years, the population has almost doubled from approximately 216,000 in 1990 to approximately 402,000 in 2010. In addition the county is projected to grow to approximately 555,000 in another 20 years; the county had nearly doubled its population every 20 years since 1950 (population was 22,000 in 1950).  The growth of this county has led to a decline in agriculture and an increase in pollution.  These constraints from growth and development have ultimately resulted in several ecological issues that this study will attempt to address.   Furthermore, this study will identify the spatial patterns associated with the growth and how it has grown over the years.
RASTER LAYERS
Maps (i.e. Historic, topographic, pre-1990 census maps)  – Any scanned map that has features that can be digitized to fill in gaps from all other data used.
SRTM – Any type of elevation data needs to be used in order to explain why certain areas have not been affected by urban sprawl.
Orthorectified Aerial Imagery – This type of imagery will provide most of the historical data needed to determine foundation data for comparing the present to the past.  Each image used can be digitized to extract data into vector format.
Satellite Imagery – This type of imagery will allow various types of sensors to determine changes via comparing two or more images identify change detection in vegetation, ecology, infrastructure, and other important features in foundation data.
Table 1. Satellite remote sensing data for ecological research.
Satellite
Launch
Sensors
spectrum
spatial resolution (m)
temporal resolution (days)
Landsat
1972
MSS, TM
V, IR
15-80
16
SPOT
1986
HRV
V, IR
10-20
5-26
IRS
1988
LISS, WiFS
V, IR
5-200
5-24
NOAA
1970
AVHRR
V, IR
1100
0.5
OrbView
1998
SeaWiFS
V, IR
1100
1
Terra
1999
MODIS
V, IR
250-1000
2
ERS
1991
AMI
microwave
20
variable
RADARSAT
1995
SAR
microwave
20
IKONOS
2000
IKONOS
V, IR
1-4
KOMPSAT
2000
EOC, OSMI
V
6-800
 
VECTOR LAYERS
LULC (Land use land cover), including current and historical datasets  – This provides an idea of where the different feature classes of land type and uses are located.
Census: 1990 and newer census tracts, population – Census data reveals where the population is with any given area.
Hydrographic: rivers, streams, lakes, watershed – Hydrographic features are part of a foundation dataset.
Infrastructure: roads, rails, powerlines, pipelines – Infrastructure features are part of a foundation dataset.
Environment: Air Quality maintenance area, water quality monitoring station – Reveals location of areas that monitor changes in the environment.  This allows for the validity of data acquired in relation to air and water quality data compared to sensors that capture quality via remote sensing.
Boundary: County and cities – Provides an outline for the areas of interest.
METHODOLOGY
The methodology used for studying the issue of population affecting the local ecology requires two different datasets themed to a specific time frame, one pre-1990 dataset and one post-1990 dataset.  The area of interest that will be studied is within the county borders of Prince William County, Virginia, including the cities of Occoquan, Manassas, and Manassas Park.  A foundation dataset based on the aforementioned criteria is needed to identify changes and challenges that urban growth has had within the county.  GIS allows this foundation dataset to be overlaid with land cover and other raster and vector files that have a relation to identifying the affects of increased population in the county with files that can help determine factors that affect the ecology such has changes in county infrastructure.
In order to accomplish this, GIS plays an instrumental role in conducting spatial analysis between feature classes and identifying relationships among the two topics: population and ecology.
Not all datasets are readily available in can be used immediately for spatial analyses.  Most of all raster files in this project will have to be scanned and inputted into the system.  At this point, each file, whther it is a photographic image or a map needs to be spatially referenced in the area it is detailing.  Digitizing these types of files is a necessity once the files are geo-referenced in order to extrapolate any valuable vector datasets from the map or images, such as landcover and landuse, vegetation, missing pieces to infrastructure (i.e. roads, buildings, parks, waterways, et cetera), et cetera.  Most of the raster files that are not used for creating vector datasets will be used for identifying air quality, pollution, water quality, and most other ecological readings within the county.
Population data acquired from the U.S. Census Bureau and Aerial Photography will be monitored over the past 60 years, in 5 to 10 year increments depending on how much the population has changed the landscape of the county.  Each 10 year increment changes will be identified in GIS and then compared to see the progression of change temporally.  The decrease of agricultural land will also be identified in GIS via this process.
CONCLUSION
The results of this project should determine what areas within Prince William County have endured more drastic changes than other areas, as well as what areas need to be protected from any further development.  In addition, this project will visually and temporally depict the changes over time in regards to population growth, infrastructure changes, changes in water levels, air quality animations, and vegetation changes.  Overall, the results will identify spatial patterns that have directly impacted how the area has grown into what it is today from what it was 60 years ago, while simultaneously affecting the ecology of the area.
LIMITATIONS
This most anticipated roadblock will be the acquisition of data needed to fulfill all the requirements in order to do spatial analysis and observations.  Secondary to do this, the time involved to complete this project will be dependent on the amount of change and extraction that is needed from the ingestion of maps or photographic images.  The more gaps in the vector data, the more time needed to extract from the raster files.

#GIS #geography #remotesensing #geospatial #humangeography #cartography #spatial

In addition to my tumblr blog which is themed for pictures of anything geo-related – I have recently created an additional blog which will be more text-based with geographic storyboard postings.

Check out my new geographic blog!

Geographic Information Systems (GIS) applications in social science are becoming more and more frequently used throughout the world in understanding several sub-fields of geography.  For this posting I will be discussing specifically the human geographic aspect that concentrates on understanding local populations and the implications of social change from effects of economic, political, geographic, and ethnographic issues through the use of GIS.  The typical uses or norms of GIS applications usually include science-related mapping, utility mapping, and/or disaster response/humanitarian efforts, and last but not least, map-making in general.  The social sciences and human geography are often overlooked and many people that I have encountered in life, school, and work are doubtful of the possibility of mapping human cultures.  This may be because in a global world today, most cultures are becoming more intermingled than ever before.  However, though globalization is beginning to merge many cultures, the majority of cultures still have unique characteristics that history has lent to them.
In GIS, there are many layers that would assist in developing spatial relationships among various aspects of human geography. This application is becoming more and more reliant by the United States government as a result of the issues with our military not understanding the cultures of Iraq and Afghanistan before the invasions earlier in the century. Not only do federal governments have a vested interest in human geographic applications, but non-government organizations also have their fair share of a need to understand the world from a social science perspective.
As a proof of concept, the following 3 layers are an integral part of this overall system, but keep in mind there many layers that are needed in order to understand the big picture.
Ethnicity Layers: These layers would consist of the cultural groups within say for instance in Iran such as the Azeris, Kurds, Iranians, among various other smaller cultural groups. A polygon layer would represent the generalization of where these groups mainly have geographic control over;  however, there may be overlap among the polygon layers in a macroscopic view of the region. This would provide a baseline for understanding any implications the Iranian government would enforce on the local population.
Neighborhood/City Layers: These layers would provide more of a microscopic view of the parts of the regions, specifically cities or urbanized areas. Within these urban areas, a mixture of cultural groups may be present. Identifying the neighborhoods specific to a particular group would help to isolate groups and provide geographic context to conditions under the assumption that segregation is prevalent in the city.  I have noticed through my studies that even in a global world, there is still much segregation in neighborhoods because ethnic groups and religions tend to stick with like people.  Also, the mix of ethnicity would be more visible with these polygon layers, because at larger scales, a GIS user can begin to see the relationship and isolation of each of the groups.  A new technique such as settlement mapping can also divide formal from informal neighborhoods assisting in identifying certain demographics of people.
Religious layers: These point layers will help identify any historic or religious sites across an urban area to assist in the overall analysis of identifying spatial attributes to a particular group. Examples of point shapefiles would be churches, mosques, religious sites, relgious institutions, religious monuments, et cetera.  Alternative to point layers, polygons may also be helpful from a macroscopic scale for identifying which religions tend to favor certain geographic areas over others.  This may be from diasporas or history.
Researching human geography can be done and converted into geospatial information.  Another thing to keep in mind is that geographical text can be extracted and developed into data, which is one thing in any social science field, is part of the data collection.  One would have to convert text into geographic data, not only from information with geographic locations, but the surrounding context.  There are many ways to go about finding information.  Many anthropologists and other related fields have published many studies regarding cultures and civilizations.  These types of papers have an abundance amount of geographic insights, references, and data that can be extracted in to spatial data.
Commerical remote sensing imagers (i.e. Orbview, Geoeye, DigiGlobe) may also lead a helping hand; many cultures or ethnic groups in the eastern hemisphere have their own specific characteristics for architecture, buildings, and homes.  Many of these architectural distinctions are observable from space, especially with a favorable look angle.  If the imaging platform takes a snapshot of an area at nadir, it may be more difficult.  Other ways to find information is through social media sites that promote collaborative mapping and that may also provide insight into human geography.  Sites like Wikimapia, openstreetmaps, and amateur cartographic sites provide insight into cultural data.  Of course there are many different sources of information, and it would be someone’s job who is involved in human geographic mapping to analyze all possible layers to establish a final cartographic map that details the human geography of an area.
Keep in mind, if you are expecting 100 % accuracy on any of these layers, then you are in the wrong business, as you should always question the data since nothing is perfect.  There are many things to take into consideration when looking at mapping human geography.  You also have to consider what is the end use or final deliverable for the project.  Some geographic layers that are important to conduct such analyses are terrain, elevation, roads, buildings, hilltops, rivers, transit zones, local language, ethnicity, education, and demographics.  Where does one get all of this information?  The data can be acquired via remote sensing, various open sources, or other means.  All this data plays into the bigger picture, but most of us take them for granted.

Ease of mobility is a huge factor in cultural mapping.  In rural areas across Asia, even if the groups are forced out, they tend to stick together.  Not all populations have the luxury to send their kids to Tehran University or hop on the highway to go to Kashmir on a nice scenic vacation.  Ethnicity is another hindering factor like race is still an issue in America.  Therefore the infrastructure plays a huge role in identifying areas where cultures are prevalent.  In the United States, when people emigrate there, they tend to stick together with like-minded and like-speaking peoples hence why we still see segregation in our urban cities.  It’s not much different when cultural groups are forced to flee their land to another part of a country or to neighboring countries, hence why you see other ethnicities such as the Turkmens in Afghanistan or Iran even though there is a country of Turkmenistan.

Furthermore, there are many factors involved in understanding this and aggregating information is the key to success.  You need to acquire as much data and information that one can.  In addition to data, information is a key aspect to this in providing context to areas.  The world is not as isolated as it once was and there is a plentiful amount of information and data that would be suffice for a fairly accurate assessment of an area; you just need to know where to find it.

I just wanted to provide a little taste of what could be done more than the typical GIS applications that everyone knows about.  Hope this helps!

Brian G – @geocrusader80

All:  If you live in the United States, please take this survey sponsored by the American Geographic Society.  You do not have to like geography to take it 🙂

Survey: Geographic Attitudes and Perceptions by Adults

Geospatial & GIS Journal

  1. Video — A GIS Journey — National Geographic
    December 23, 2011 6:32:35 PM EST
  2. Geospatial Websites Upgraded: The US Topo and Historical Topographic Map Collection websites had added an interactive map application to the home pages. The flash thumbnails of original maps display all available versions of the featured series in an animated format. The display allows the user to view the maps in chronological order, access larger versions and the map and go directly to the download services. The first showcased series are six topographic maps from the Boothbay, Maine area – ranging from 1893 to the present. http://1.usa.gov/82461k, http://1.usa.gov/oSPTDv
    December 9, 2011 6:00:36 PM EST
  3. The Geospatial Revolution Project
    October 7, 2011 2:35:15 PM EDT
  4. New edition of Geographic Information Technology by @Geocrusader80 bit.ly/ti2A9f #GIS #geography #remotesensing #cartography #geo
    December 21, 2011 8:32:54 PM EST
  5. How to Fold a Google Map bit.ly/tUUG6k | #geospatial #GIS
    December 22, 2011 9:49:51 AM EST
  6. The past, present & future of #GIS: esp.tl/sKstNm #geospatial
    December 22, 2011 7:12:30 AM EST
  7. What is Remote Sensing?
    November 21, 2011 4:23:33 PM EST
  8. DMTV #5: Remote Sensing, Haiti and Social Geonetworks
    February 6, 2010 3:44:50 PM EST
  9. Geography is changing
    September 17, 2006 9:24:00 AM EDT

Interesting article/blog posting on how organizations are using remote sensing and GIS mapping technologies for socioeconomic issues and natural disasters.

Social Impact through Satellite Remote Sensing – Visualizing acute and Chronic Crises beyond the visible spectrum

Good articles…

Mapping News by Mapperz

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The GeoChristian

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