Wednesday, May 25, 2016

History of Landsat

The Thermic Mapper was designed in the 1970’s and that has slowly evolved and been improved into the technology of Landsat today. The technology was used by NASA to be  satellites and used to map out different parts of the globe. Many of the new additions were very similar and in some cases identical other than some bug fixes. In the 1990’s the technology gained funding and support and 1992 Landsat-7 was made on an improvement from Landsat-6. The advancements today have helped to produce new maps but even now failures happen all the time. The future is bright when talking about accurate digital maps and with Landsat mapping more accurate than ever it is possible to examine the earth on a new level.

Deforestation in Africa

'Throughout Africa as a whole, nearly 60% of new agricultural land was derived from intact forests, and another 35% came from disturbed forests. The remaining 5% of new agricultural land was taken from shrublands'. 

More than 80% of new agricultural land came from intact and disturbed forests in the 1980's and 1990's. Although differences occur across the tropical forest belt, the basic pattern is the same: The majority of the land for agricultural and tree plantation expansion comes from forests, woodlands, and savannas, not from previously cleared lands. The majority of the land for agricultural and tree plantation expansion comes from forests, woodlands, and savannas, not from previously cleared lands. The article explains that by the year 2050, worldwide demand for agricultural products is expected to increase by ∼50% and evidence suggests that tropical countries will be called on to meet much of this demand.

Without new provisions, lucrative and increasingly large-scale agriculture will continue to clear forests in the path of expansion. However, with policies such as REDD (Reducing Emissions from Deforestation) in place, farmers and large-scale producers would have greater incentives to improve management of previously cleared land.

Gibbs, H. K., Ruesch, A. S., Achard, F., Clayton, M. K., Holmgren, P., Ramankutty, N., & Foley, J. A. (2010). Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s. Proceedings of the National Academy of Sciences107(38), 16732-16737.

Locating Farmers Market

Most farmers’ markets operate on a weekly basis and they had to take this into account when creating these maps. Based on hours of operation, we can generally classify farmers’ markets into weekday morning noon markets, weekday afternoon evening markets, and weekend markets. Weekday morning noon markets usually run from 8am to 12pm or 9am to 1pm on weekdays. While these factors vary, we can still classify customers into two groups, workers and non-workers and assume that workers have regular work hours of 8am-5pm during weekdays.

The two models focus on identifying locations and associated operating times for farmers’ markets to maximize accessibility to all people in terms of travel distance. The PMP, or 'p-median problem', is a a mathematical formula used to asses a range of variants. Based on this PMP, this range of variants in the study can be explored more thoroughly. Additionally, studies have investigated alternative ways of modeling travel distance/time such as public transportation.

Tong, D., Ren, F., & Mack, J. (2012). Locating farmers’ markets with an incorporation of spatio-temporal variation. Socio-Economic Planning Sciences46(2), 149-156.

Tuesday, May 24, 2016

Usability Study on Different Visualization Methods of Crime Maps

Crime mapping has become one of the most common uses of GIS, and for good reason this is one of GIS’ most useful applications. This study set out to answer a few questions. The first question is how GIS methods can be applied to help visualize crime data through modeling, and how well people can define differences according to the classifications on the map. The second question is whether or not cartograms can give good representations of crime data. The study took place and focused on a Hungarian city that averaged between six and seven thousand crimes per year. The results were that they found that cartograms could indeed be good solutions to modeling crime data.

Podor, A. (2015). Usability Study on Different Visualization Methods of Crime Maps. International Journal of Geoinformatics11(4).

Toward critical spatial thinking in the social sciences and humanities by Michael F. Goodchild • Donald G. Janelle

The past couple of decades have opened floodgates of possibility in spatial representation via revolutionary computational power of GIS.  The hydropower of GIS has flowed far past scientific fields, the obvious candidate for GIS, seeping into the humanities.  The coupling of a recently discovered universalism of georeferencing (ease of spatially representing any field) and technology the modern computer has bestowed upon the world, GIS continues to gain momentum.  Economics, anthropology, archaeology, history, and religious studies utilize the GIS in tracking cultural heritage and societies, validated in the GIS in the Humanities and Social Sciences International Conference.

The integration of GIS into humanistic courses hints a shift from "disciplinary to integrative knowledge systems."  GIS technologies have issued the importance of place in humanities and are now instrumental in some policy making, what the White House calls place-based policies.  GIS also plays a role in research, social process, and environmental understanding.

In recent years, the term spatial has been used as an "umbrella term to include spatio-temporal."  Time and space warp their way into fields such as archaeology which analyzes ancient civilizations and archaeological development through time.  The concept of space is universal in its relation to an array of concepts and fields, and a necessary component in education.

GIS finds agency in humanities, which only marginally crosses with in-depth GIS analysis, because learning the theory is not a necessity in creating spatial representations, unlike in math and statistics.  A more embedded approach of spatial reasoning in education is necessary so that critical reasoning can meet spatial concepts; this is where GIS and the humanities collide.

Geospatial Location of Music and Sound Files

Using GIS to locate where something came from on the internet is a relatively new concept.  By mapping where different audio files come from it can benefit the public in a number of ways.  First of all, it can help narrow or refine searches based on what is most popular in your area, GIS can also help market certain types of music or inform artists where they should focus their music tours.  It can also help select sites that are geographically closer to users downloading music, therefore creating faster download times.  Having the knowledge of what is currently most popular and where can be difficult for research being done in music, and using GIS may help in that.  GIS used in collaboration with Music Information Systems, or MIR, will obtain the data necessary for these projects.  The MIR being used for this research is different from the rest in that it only uses information from what is available on the web.
The map shows European sound file distribution by percentage, meaning the numbers shown are the percentage of the sample's sound files retrieved.  Having the geographic information of these numbers is important to be able to compare it against other statistics that may be available for that country. 

Monday, May 23, 2016

In this article Sui points that the voter turnout of local and precinct levels indicate how involved the specific population is intrigued by local referendums. The image above shows three different elections and the voter turnout that participated in those elections in College Station, TX. In the top figure, voter turnout was poor. In the second figure, more of the population participated in the election. In the third sigure, you can see that there was a higher voter turnout than the previous elections and there was a high concentration of voters in a clustered location. This clustering in voter turnout if cause by the possible effects the proposed referendums could have in that specific area. The controversy level raised concerns amongst eligible voters persuading them to get involved in the political process in order to vote for against these propositions that could have positive or negative affects to the individual and the area.

Sui, D. Z., & Hugill, P. J. (2002). A GIS-based spatial analysis on neighborhood effects and voter turn-out:: a case study in College Station, Texas. Political Geography21(2), 159-173.

land change

The land is going to change constantly, and whether it's a subtle change in climate or a long term effect of deforestation changes will occur everywhere. The earth's population emits a lot of greenhouse gasses and those are causing major changes that will affect many parts of the world. Areas that are affected by greenhouse gasses will become extremely hot or just hot enough to change the environment, some adaptations from this could be an extension of the land used for crops. The land changes itself are not solely dependent on the amount of carbon we produce, many of the changes that occur are because of using up a resource too quick or building on top of important parts of the ecosystem. Underdeveloped countries can be affected greatly by changes like these, due to pressures from wealthy countries and political problems many of the tropical forests are becoming destroyed with little resistance. One land use that has had great change in its time is the temperate forests, the united states and Europe both used almost all available resources to become wealthy and have hurt the ecosystem terribly. The land use of many well developed countries has been shifted to suit more densely populated areas with food and water able to be brought in. The changing in environments have less of an effect on many well developed places due to the wealth that can support them. Changes in land are going to happen at a faster rate than normal due to human activity and can even be “controlled” by big spending and politics.

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Philly Phood habits

Efforts to define local food systems are widespread. One popular way to delineate “local” is circumscribing a circle of a radius around a chosen center point. The “100 mile diet” is one such popular definition. An important step in mapping local food systems is that there must be an identification process in order to recognize the relevant components of the local food system studied. To understand the structure and scope of the current local food system in Philadelphia, 'informal interviews were conducted with various participants in the system including urban farmers, Community Supported Agriculture (CSA) owners, farmers’ market operators', among others. Essentially the study aimed to pinpoint the healthiness of local food practices in Philadelphia.

152 routes were computed representing all routes taken by farmers bringing products to the city’s farmers markets. The number of routes is larger than the number of farms because many farms supply more than one farmers market. Each trip is counted independently because most farmers supply markets operating on different days of the week requiring separate travels. In performing this analysis, there was no suggestion that all this land can or should be cultivated for food. Many other factors determine the use of land for food production within the city and require further study. 

Kremer, P., & DeLiberty, T. L. (2011). Local food practices and growing potential: Mapping the case of Philadelphia. Applied Geography31(4), 1252-1261.

Communicating Geographic Information in a Digital Age

Goodchild's article discusses how communication has helped promote the knowledge and use of GIS technology and services. It is argued that GISs should instead be considered media since it allows senders to share information and messages to the receiver, just as newspapers and other forms of media communicate more general information.However, Goodchild argues that GIS's information is more "intrusive" and in depth, as it gives precise information like how cold is "cold" with a precise temperature and where "here" is by giving a precise location.
Since the invention of digital media, the process of GIS has changed dramatically. This model shows the process of GIS and how it has changed with the change towards a digital age. 
Because of the digital transition, GIS software has become cheaper and more accessible and data-collecting systems have been able to collect more data at lower costs, making GIS more accurate and efficient. However, it is also cutting down on jobs like cartography and map-making by hand, now that maps can be created and drawn electronically. 

Goodchild, M. F. (2000). Communicating geographic information in a digital age. 
Annals of the Association of American Geographers90(2), 344-355.