Tuesday, February 28, 2017

The Normalized Difference Vegetation Index (NDVI): Unforeseen Successes in Animal Ecology

This authors of this review article discuss the latest applications for the Normalized Difference Vegetation Index (NDVI) for ecological research. Since its development in 1981, researchers have greatly expanded the breadth of this technology's utility for studies of the natural world. NDVI has been established as a central tool for the assessment of historical and future biodiversity consequences resulting from changes in climate, vegetation cycling, and primary productivity of plants. This is made possible, even in areas with sparse vegetation, by NDVI's ability to utilize climate models that compile information from historical patterns of vegetation dynamics and from anticipated trends in changing climates to make predictions about the most likely effects on habitat biodiversity.

NDVI technology, however, does have some limitations for its ability to accurately explore the link between climatic variation and ecological processes. Since the collection of NVDI satellite data began in 1981, that is the most historical records it can draw from, which create the possibility that the models constructed by this technology will unreliably represent ecological factors that change on a slower time-scale. Another potential hurdle that researchers implementing NVDI technology must address is the accurate portrayal of human impact on ecosystems, because this is the primary threat to their persistence. Much of the limitations raised by the reviewers of this articles are said to be effectively mitigated if accurate ecosystem data from outside NDVI databases are used to supplement study efforts and refine the renderings of associated climate models. Emphasis on interdisciplinary study efforts between ecology, geophysics, and remote sensing is also mentioned as an additional means of promoting more accurate use of satellite data for ecological research applications.  

Pettorelli, N., Ryan, S., Mueller, T., Bunnefeld, N., Jędrzejewska, B., Lima, M., & Kausrud, K. (2011). The Normalized Difference Vegetation Index (NDVI): unforeseen successes in animal ecology. Climate Research46(1), 15-27.

Monday, February 27, 2017

Neighbourhoods and health: a GIS approach to measuring community resource accessibility

This study, conducted by Jamie Pearce, Karen Witten, Phil Bartie, looked at how accessible different communities were to different health related resources. They examined different resources such as: shopping, education, recreation, food stores, and health facilities. They broke down a map of an area like Christchurch by neighborhoods and looked at how far it would take different people in different neighborhoods to get to places.

They continued to use maps like this to come up with a general census of how far people are from these community resources. They found when looking at New Zealand as a whole the travel time for people coming from 'low accessibility' neighborhoods 23.22 minutes while coming from 'high accessibility' to being only 2.83 minutes. Although this is a very large gap this study examined different neighborhoods all across New Zealand both urban and rural.

Pearce, J., Witten, K., & Bartie, P. (2006). Neighbourhoods and health: a GIS approach to measuring community resource accessibility. Journal of epidemiology and community health60(5), 389-395.

Utilizing spatiotemporal analysis of influenza-like illness and rapid tests to focus swine-origin influenza virus intervention

This article discusses the pandemic of a novel strain of H1N1 swine-origin influenza A virus that emerged in the United States and Mexico in the spring of 2009. The ability of real-time reports of influenza-like illness symptoms and rapid influenza diagnostic tests were examined to approximate the spatiotemporal distribution of PCR-confirmed S-OIV cases for the purposes of focusing local intervention efforts.
The results suggested that influenza-like illness symptoms and rapid influenza diagnostic  spatiotemporal analysis may be useful in understanding the nature of S-OIV outbreaks in space and time. An understanding of  real-time intervention and control can effectively inform when and where local intervention should be focused and minimize outbreak impacts.

Wilson, J. G., Ballou, J., Yan, C., Fisher-Hoch, S. P., Reininger, B., Gay, J., . . . Calvillo, F. (2010). Utilizing spatiotemporal analysis of influenza-like illness and rapid tests to focus swine-origin influenza virus intervention. Health & Place,16(6), 1230-1239. doi:10.1016/j.healthplace.2010.08.010

GIS and Policy

GIS, Public Service, and the Issue of Democratic Governance:
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Akhlaque Haque

In this essay, Haque discusses the role GIS can play in examining social, economic, and political circumstances, specifically in regards to how policy is implemented.  Within this, Haque introduces technocracy, which refers to a government in which technically trained experts influence society by virtue of their specialized knowledge and position. Essentially, throughout this, Haque takes the position that well trained experts in GIS have the opportunity to positively impact policy, if given the chance. Moreover, he argues that GIS should be engrained within public service in order to ensure accurate representation of economic disparities, racial lines, and political differences in regards to how people ought to be represented and governed. I don’t particularly agree with the notion of a technocracy, I think there is place for educated elites, and while I desire my governing body to be educated, I do not think it needs to be entirely controlled by the opinions of technicians. However, I do appreciate that there ought to be a larger space devoted to ensuring the discourse of how different people are actually being governed, and seeing that tangibly on a map is invaluable.  

Haque, A. (2001). GIS, Public Service, and the Issue of Democratic Governance. Public Administration Review, 61(3), 259-265. Retrieved from http://www.jstor.org/stable/977598

Effects of Urbanization on Mammal Species in the U.S.

Due to a rapidly growing population in the San Antonio and Austin areas, urbanization in central Texas has developed quickly over the past few years. Although current nature preserves live alongside these urbanized areas, it's important to research whether the development on the land will still have an impact on these mammals.

A study was conducted where researchers filmed with motion-activated cameras at 72 sites across 6 different regions throughout Austin and San Antonio. Ten different urbanizing factors were considered when concluding the influence of urbanization on medium-sized mammal species.

It was concluded that even though urbanization is ongoing and will develop over the years, natural preservations continue to provide a habitable area for many species. None of the 7 species studied showed a negative correlation with urbanization. This study highlights the importance of green spaces and natural havens to keep species thriving.

Haverland, M. B., & Veech, J. A. (2017). Examining the occurrence of mammal species in natural areas within a rapidly urbanizing region of Texas, USA. Landscape and Urban Planning157, 221-230.

Classifying the Baltic Sea Shallow Water Habitats Using Image-Based and Spectral Library Methods

Remote Sensing and GIS isn’t just for analyzing terrestrial environments.   A study by Vahtmae and Kutser (2013) use geospatial data and regression models to gain an understanding of the health of the Baltic sea.  The authors point out that, as one of the most polluted, the Baltic Sea’s ecological conditions need to be protected.  Due to the lack of information, insufficient data, and scientific resources, environmental planning has been limited and not very effective (Vahtmae, Kutser, 2013).

The health of a marine environment can often be evaluated by measuring benthic macrophyte habitats.  The authors indicate a reduction of the abundance of certain macroalgae, an indicator species in the Baltic Sea.  By using large-scale analysis of marine habitats, they will be able to gain a broader understanding of marine habitats and provide evidence with which to gain environmental change.

Since the Baltic Sea is a shallow marine environment with several terrestrial imputs, particulate matter, dissolved organic matter and phytoplankton blooms stay suspended large areas of the sea.  Image-based supervised classification techniques such as Maximum Likelihood, spectral Angle Mapper, can make it very difficult for certain types of remote sensing, not to mention time consuming and costly. 
This article describes several alternative approaches.  One such approach uses a modeled spectral library, in which remote sensing reflectances are compared to simulated reflectances. Though the known properties of the substrates and the optical properties of the water are necessary for this form of image classification and may negatively affect the accuracy.  The third approach, is a basic classification method such as Spectral Angle Mapper, or SAM which has no sensitivity to illumination or albedo effects.  With this method, one can change the accuracy and compare data with spectral library in the same instance. 

The study tested both image-based approach and spectral library approach.  Though the image-based method performed better than the spectral library method, they had to take into account that the turbidity of the water could change the results.   In evaluation of the data, the suitability of the two methods for shallow water habitat mapping show basically no difference between airborne hyperspectral and satellite multispectral data (Vahtmae, Kutser, 2013).

This is just one of many studies that show the use of GIS in monitoring the health of marine environments.  Due to more accurate means of evaluation, this could become key in maintaining a balanced ecosystem throughout our waters.

Vahtmäe, Ele, and Tiit Kutser. "Classifying the Baltic Sea shallow water habitats using image-based and spectral library methods." Remote Sensing 5, no. 5
(2013): 2451-2474.


With the rise in competition and battle for the top spots in competitive sports such as football, more data is needed. However, with the current state of data there is limited upward movement. This has caused an increase in a need for geo spatial data, that can be concluded by GIS work.

Using tracking data and event data, maps are able to be constructed to represent this data form the game. By first mapping the field itself, you can use spatial elements such as the players, ball, and referees to get spatial data. This blog analyzes that while it is in the beginning phases, the door is open for GIS to model a game more concretely than current practices in the future. The lacking knowledge is how this data can be connected to represent the game as a whole instead of "snapshots" of individual portions.

Kotzbek, G., & Kainz, W. (2014). Football Game Analysis: A New Application Area for Cartographers and GI-Scientists. In Proceedings (Vol. 1, pp. 299-306).

Drug Pricing in the US

An increasingly popular topic in our national news is the pricing of pharmaceutical drugs in North America. Our drug prices increase annually and are drastically higher in almost all categories than most, if not all other developed countries. Access to healthcare and price varies depending on your location in the United States but chronic eye disease does not vary from place to place. According to new Medicare data, the way doctors treat chronic eye disease does differ from location to location and those changes have major effects on personal and US budgets.Steven Rich/The Washington Post
The map above shows the use of Lucentis a drug used to treat eye disease differs from area to area. The brightest reds show places where the vast majority of the money spent in treating the disease is spent on Lucentis; the deepest blues, shows places where most of the money spent treating the disease is spent on its cheaper alternatives.Such variety in treatment calls into question whether doctors are treating patients based on the best available evidence, or other considerations.

Rich, Steven. "These maps tell you everything that’s wrong with our drug pricing system." The Washington Post. WP Company, 11 Apr. 2014. Web. 27 Feb. 2017.

Mapping Micro-Urban Heat Islands using LANDSAT TM and a GIS

In this article, the author discusses how LANDSAT TM satellite data and GIS software were used to map micro-urban heat islands in a portion of Dallas, Texas. Unsupervised classifications were performed on a LANDSAT sub-scene to extract tree cover information which was merged with TM data to make a map showing the location of micro-urban heat islands and wooded areas. Heat islands are generally described as urban areas that produce higher than background surface temperatures associated with rural surroundings.  Major factors leading to the formation of heat islands include; the effects of street canyon geometry on radiation, the effects of thermal properties on heat storage release, and waste heat from residential and other buildings.
The study area within Dallas is named White Rock Lake. It contains both older and newer residential neighborhoods, major highways, shopping centers, a warehouse district, wooded areas, and a large lake, providing variable land cover with contrasting thermal regimes. The methodology for mapping out the area involves LANDSAT TM processing and classification, thermal map generation, and GIS merging and final map production.

In the figure above, the hot spots in the White Rock Lake area exist as heat island patterns with the warmest temperatures in the center and coolest temperatures around the edges.
After examining the maps, it was noted that hot spots throughout this urban area were radiative in nature. The hottest areas were where land use was associated with impervious cover such as a large warehouse district, asphalt parking lots and roads, and a large number of apartment complexes. Also, new neighborhoods were significantly warmer than older neighborhoods. The coolest areas were those with heavy tree cover, including the forested park just north of the lake.

Aniello Cathy, Morgan Ken,  Busbey Arthur, and Newland Leo (1994). Mapping Micro-Urban Heat Islands Using LANDSAT TM And A GIS. Computers & Geoscience. Vol. 21, No.8. 

The effects of deforestation and climate variability on the streamflow of the Araguaia River, Brazil

From the 1970's to the 1990's the Araguaia River in Brazil had a huge increase in water discharge. This large increase was believed to correspond with the deforestation seen in the area.

In Brazil the Araguaia watershed has seen massive amounts of deforestation. The amount of deforestation in the twenty year study period was estimated to be as high as 55%. This amount of deforestation leads to dramatic hydrological changes in the area, such as increased runoff .
The conditions created by the deforestation has lead to a nearly 25% increase in water discharge from the river. This increase is even more astounding when compared to a increase of only 2.5% precipitation. Computer simulations of the changes over the years point to 2/3's of the increase come directly from Deforestation.

Effects of increased runoff.

  • Larger river outputs 
  • Increased erosion of sediment 
  • Increased pollutants in the water 
  • Increased vulnerability of flash flooding   
As a result of this the Brazilian Government has increased protection over deforestation. Proper management of the area along with protecting the area from deforestation will lead to a decline in the increase of runoff, and could even lead to a overall reduction of discharge.

 Coe, M. T., Latrubesse, E. M., Ferreira, M. E., & Amsler, M. L. (2011). The effects of deforestation and climate variability on the streamflow of the Araguaia River, Brazil. Biogeochemistry105(1-3), 119-131.

The Power of Naming

This article addresses the effects of racial commemoration on segregation. This study discusses how whiteness permeates into every seemingly colorblind facet of life. When places are named after African-American leaders, the neighborhoods around those monuments or areas tend to be more racialized. Since individuals are typically commemorated in the areas where they lived and died, those areas tend to be minority communities already. Unfortunately, these places tend to receive derogatory names and associations with violence and poverty, making them less desirable for individuals who associate these qualities with race to move to the areas. The article uses mapping technology to study places named after African-Americans and the result of unintentional segregation. Furthermore, places and things named after African-American leaders tend to be located in already majority minority places, creating a self-fulfilling prophecy of segregation in neighborhoods, regardless of colorblind policy. 

These figures showcase the positive correlation between commemorating African-Americans and the percentage of African-Americans in counties. States where there is a high  African-American population, tend to have more commemorations for African-Americans as well, however, the counties tend to be highly segregated, with a correlation to the commemoration policy. 

Tretter, E. M. (2011). The power of naming: The toponymic geographies of commemorated African Americans. The Professional Geographer63(1), 34-54.

Mapping Micro-Urban Heat Islands Using LANDSAT TM and a GIS

In this article, we look at a study that uses Geographic Information Systems (GIS) and LANDSAT TM (satellite data) to identify Micro-Urban Heat Islands (MUHIs) in Dallas, Texas, and to compare the spatial distribution of these MUHIs and tree density. Micro-Urban Heat Islands are "isolated urban locations that produce 'hot spots' within a city." Often these heat islands lead to a change in the climate of the area, and "most urban areas around the world with populations greater than 100,000 have heat islands that are 1-4.5 degrees (celsius) warmer than rural temperatures." One idea that has been suggested to reduce this effect of heat islands is to add more tree cover to urban areas.

The study mapped the MUHIs in the White Rock Lake area of Dallas using LANDSAT TM processing and classification, thermal map generation, and finally, a process of merging with GIS to produce the final map. Using LANDSAT TM, those conducting the study were able to create a thematic map which showed different pixel clusters, which were then grouped together to identify roads, bodies of water, buildings, grass, etc. Using the GIS layer that showed tree cover/density, the LANDSAT TM data was merged with tree cover to create the final map showing the distribution of tree cover compared to heat islands.

The figure above shows tree cover and MUHIs. This study concluded that heat islands are 5-11 degrees (celsius) warmer than surrounding areas by midmorning. The coolest areas within this area of Dallas were those with more tree cover, which suggests that increasing the density of trees within urban areas may be effective in decreasing the climate changes that come from MUHIs.

Aniello, C., Morgan, K., Busbey, A., & Newland, L. (1995). Mapping micro-urban heat islands using LANDSAT TM and a GIS. Computers & Geosciences,21(8), 965-969. doi:10.1016/0098-3004(95)00033-5

Tweet Me Your Talk: Geographical Learning and Knowledge Production 2.0

Nadine Schuurman argues that with the rise of internet use, our learning styles are rapidly changing. She describes this as a negative change, representative of our inability to understand previous forms of information. Brains and the way that they function are constantly changing (brain plasticity), and advances in technology/increases in use of technology have certainly affected our brains (Schuurman 1). 

One of the primary negative effects that technology use has had on our brains is a decrease in our attention span; we cannot focus as easily or for as long as we used to (this is particularly prevalent in developed countries where the internet is more commonly accessed) (Schuurman 2). We are not as skillful when it comes to reading large amounts of information on print, rather, we excel at finding key pieces of information quickly. 

Schuurman supports her argument by showing the ways in which the academic sphere caters to this type of learning in the format various resources (e.g. journal formats, academic reviewing, & academic social networking) --as pictured below. Schuurman argues that not only has our method of learning changed, we have started to cater to this new type of learning. 

Schuurman, Nadine. "Tweet Me Your Talk: Geographical Learning and Knowledge Production 2.0." 
The Professional Geographer 65.3 (2013): 369-377.

Sunday, February 26, 2017

A GIS-Based Football Stadium Evacuation Model

Sporting events and the sport industry are a billion dollar industry. With the rise of such popularity and with almost 50,000,000 people in attendance at NCAA football games in 2008, these events come at the risk of terror attacks.

The purpose of this article and study was to develop a GIS based evacuation model for Southern Mississippi University in the unfortunate event of something happening.

The three major objectives were:
  1. Identify the number of evacuees and their potential origins and destinations
  2. Identify evacuation routes connecting origins and destinations based on shortest travel time
  3. Compute the total evacuation time of the stadium starting when the evacuation order is issued and ending when the last evacuee exits the evacuation zone
Even though this 33,000 seat stadium is smaller and would probably not be attacked, the structure and flow are the same of a larger stadium and can be applied and scaled. 

To compute travel time within the stadium from different sitting areas to exit places, an audience layer was created by evenly distributing students and non-students within their respective sections of the stadium.

The second stage of the model included the evacuation of the stadium audience from the parking lots and mobile locations to their potential final destinations, which included nearby road networks and road intersections.

The last stage of the model was performed to estimate evacuation times and routes.

This photo shows a GIS based map for locations of mobile triages and parking lots.

From this study they found the fastest route for injured and uninjured attendees and found that the football practice field was the closest and optimal location for the ambulance to arrive at. Because of this in case of emergency USM has the optimal route and location for the fastest and easiest evacuation to get people to safety. 

Zale, J. J. & Kar, B. (2012). A GIS-Based Football Stadium Evacuation Model. Southeastern Geographer 52(1), 70-89. The University of North Carolina Press. Retrieved February 27, 2017, from Project MUSE database.

Farmers' Market Variations 

Today in society it has become a popular trend for people to shop organically. We now know in more detail what kinds of things are going into our foods, and more and more people choose to shop at farmers' markets to get organic, environmentally friendly, produce. Contrary to popular belief, "research has shown that food at farmers’ markets costs less than the same item in supermarkets and growers can gain higher returns compared with selling via wholesalers, distributors or retailers to whom a share of profits would accrue" (Tong). Locations and times of different markets within local areas (within city limits for this article) are tested and mapped in order to see where and when they are chosen to take place. 

Interestingly, within the city it shows that all of the markets are held within the northern part of the county line. It is also shown that the markets are being held mostly within the afternoon and evening times, with only two weekend options. This would make it very difficult for a person who lives in the southern portion of the city limits who works a 9-5 job. Commuting and rushing to get to their local market might just take more energy, gas, and traveling that would have the opposite effect of doing good for the environment. The article concludes tat much work is needed to plan and hold famers' markets in order to create a space for all people of the county to be able to attend more easily. 

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

GIS-Based Irrigation Water Management for Precision Farming of Rice

This article presents the GIS capability to explore the view of irrigation strategy with special reference to precision farming of rice. The GIS-based water management model was developed for the scheduling daily irrigation water deliveries and regular monitoring of irrigation delivery performance. The “Scheduling”program computes the right amount of irrigation deliveries based on crop water requirements. The “Monitoring”program gives information on the uniformity of water distribution and the shortfall or excess. The displayed results allow the manager to view maps, tables and graphs in a comprehensible form to ease decision making that where the irrigation amount will be delivered as the season progresses. GIS was used as a useful tool to assist the irrigation water management program in the context of precision farming.

Different methods were used to calculate this data: Water balance model in a rice basin, Cumulative Rainfall Water Supply and Ponding Water Index. Together, these factors determined a system that workd for rice irrigation.

The information from all interacting sources is essential to assess crop water status and to efficiently irrigate rice crop as well as for improving water management. GIS user-interface technique linked with water management model can greatly assist to improve water management based on feedback of field information. The study can assist irrigation managers to improve the decision-making process in the operation and management of the irrigation system and can improve the management of water allocation systems, monitoring water distribution system in existing schemes. This study has indicated that improvements in irrigation system management based on feedback of field information can satisfy the role of the precision farming.

Kamal, R. M. (2010). GIS-based irrigation water management for precision farming of rice. International Journal of Agricultural and Biological Engineering3(3), 27-35.

Geospatial Analysis of Medical Marijuana Dispensaries and Crime in California

As many countries and cities begin to decriminalize, legalize or change policies regarding marijuana use and availability many concerns are raised. One lingering concern is whether or not increased store front marijuana dispensaries will increase crime. As more states continue considering changes to medical and recreational marijuana legislation it is important to understand how access to marijuana through these dispensaries will have an affect on public health, city zoning and planning departments. This study aimed to determine whether the density of marijuana dispensaries in Long Beach, California was related to violent and property crimes in local and adjacent areas in 2012-2013 when local law enforcement was cracking down on the number of store front dispensaries.

Through collecting data on locations of crimes and medical marijuana dispensaries for a sample of 333 census block groups, the researchers found that the density of medical marijuana dispensaries was unrelated to property and violent crimes in local areas. However, dispensary density related positively to crime in spatially adjacent areas for both property and violent crime. It can be concluded that using law enforcement to reduce marijuana dispensaries in CA reduced crime near the dispensary locations but not in these locations specifically.

Freisthler, Bridget, et al. "A micro‐temporal geospatial analysis of medical marijuana dispensaries and crime in Long Beach, California." Addiction (2016).

Friday, February 24, 2017

A GIS-based spatial analysis on neighborhood effects and voter turn-out: a case study in College Station, Texas

This study uses geo-referencing to track the outcomes of voter turnout in local elections. GIS matches addresses to the effects of voting. This study concludes that when the effects of the vote highly affect the neighborhood, voting is broadly clustered and diverse amongst the neighborhood. However, when the effects of a statute are low on the neighborhood, the votes are highly concentrated, proving that only a small group of individuals care about a legislation. 

For instance, when a piece of legislation that affects a group of people in a certain income bracket, like a tax policy, typically the votes for that legislation will be centered in the area where people of that bracket live. However, if votes are spread out, because more people voted, typically the legislation is something more broad, like an environmental policy or a safety concern. Individuals usually vote in their primary self-interest, making them less likely to vote on a policy that has no effect on their daily life, and on the contrary, people typically are more motivated to vote when a policy will directly affect them. By mapping addresses through GIS, voting patterns can be recognized and correlated to policy interests. 

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.

Tweet Me Your Talk: Geographical Learning and Knowledge Production 2.0

This article addresses the change in the way individuals process information and how it relates to geography. Instead of decoding complex, dense facts while reading, short attention spans require information to be inputted in a different way. Individuals now require short, “updates” of information, re-energizing individuals to the knowledge and allowing them to synthesize bits of information in an effective way. Geographically speaking, we may be less inclined to notice evolutionary and geographic changes. Instead of taking a “big picture” approach to geography, we are more apt at noticing emergencies. The hope is that the short attention span of contemporary society does not negatively affect geographic and evolutionary information.

Schuurman, N. (2013). Tweet me your talk: geographical learning and knowledge production 2.0. The Professional Geographer, 65(3), 369-377.

Thursday, February 23, 2017

MSU Field Study on Soil and Vegetation

Students at Michigan State University collected soil data for a near by county. They took samples of soil, coordinates of vegetation and soil samples and classified each sample. They used GIS to compile information. They were able to create boundaries of where each soil stopped and started, as well as list areas where certain vegetation was popular. 

This image shows how they were able to put the divisions of different areas of soil on a map and predict where they are coming from. Because they are able to predict where the sediment is from this could help predict floods and water runoff of the area.

This study also shows how Southwestern can apply this to Eco Lab. Because Eco Lab is already a small area it is possible to do a similar study out there.  If students in Eco Lab did a similar study it could lead to many more projects with the foundation of their hard work.

Hupy, J. P., Aldrich, S. P., Schaetzl, R. J., Varnakovida, P., Arima, E. Y., Bookout, J. R., ... & McKnight, K. P. (2005). Mapping soils, vegetation, and landforms: An integrative physical geography field experience. The Professional Geographer57(3), 438-451.