Too many people do not understand geospatial issues or even know their implications as global citizens and are unable to make effective decisions.
Every third week of November, students, families, and community members provide classroom lectures, games and challenges, and often host meetings with politicians and business leaders to focus on the importance of geography. Geography Awareness Week is supported by access to materials and resources for teachers, parents, community activists, and all geographically minded citizens of the world.
Now, as a Geographical information systems employee, I want to contribute to both geography week and GISDay.
First of all, I go back to my high school years and review my knowledge..
What is geography?
Geography is the science that studies people and place (space) and the relationship between them. Geographers explore both the physical features of the Earth’s surface and the human populations spread over it. They also examine how human culture interacts with the natural environment and how locations and places can have an impact on people.
I took the piece of map on the right from an exhibition at Yapı Kredi Culture and Art Publishing in 2018. It shows Ancient Age settlements on Anatolia.
Gregg and Leinhardt (1994) define geography as a discipline characterized by 4 features. The first is the distribution of features on the earth (eg mountains, rivers, seas, etc.) that give a place its unique character. The second is to understand why and how certain things happen where and when they happen (eg Volcanoes). The third is the relevance and connection of the events that occurred with other events (eg: Destruction of the rainforest). The last is that geography enables maps to communicate information and ideas. These four features interact with each other in many different ways. The first three of these are the basic principles of geography. The last one is the expression of the information obtained as a result of geographical researches.
What is Geographic Information Systems (GIS)?
Geographical information system (GIS), takes the geographical information, also known as spatial or spatial information, to collect, store, update, process, create, analyze and display when necessary. It is the general name of information systems that contain hardware, software and personnel.
On the left you can see a work that may be of interest to everyone. While I was visiting the Independence Exhibition held at the Isbank Museum of Turkey I saw this Kuvayi Milliye map. The events that took place in those years(1918-1921) are written on it with dates.
With this map, it is possible to better understand how we got to these days.
A GIS study ; Hurricane Harvey
Hurricane Harvey, estimated to be the most costly natural disaster in US history, left many with a difficult decision:
Should I leave my house or wait for the storm to pass?
With numerous warnings from local and federal agencies, thousands chose to heed the hurricane warnings and evacuate their homes..
Three main questions about the eviction move:
- Where did people leave?
- Where did people go?
- Where did people go?
Using Teralytics data collected from billions of signals obtained daily from cell towers and other unique sources, Esri created a map that attempts to answer these three questions.
The orange squares on the map show the places people have vacated.
For example, in the heart of Houston (shown in the right at pop-up window), about 10,000 people left the area before the hurricane hit land and only 12,838 remained, a nearly 50% drop in the Houston population.
Purple circles represent areas where people arrived.
In a week, about 15,000 more people came to the area highlighted in purple in the window on the left. In other words, the population increased by 15,000 people.
The gray polygons represent 100-year-old flood plains. Notice how most of the people in the flood plains are evacuated to places outside the flood zone (not many purple circles when the orange diamonds are in the floodplains).
The blue squares here represent areas where the population was the same a week ago and during the hurricane. It is a representation of where people have decided to stay, either waiting for the storm to end or they can’t afford to relocate.
Wonder how these areas are on the outskirts of major cities like San Antonio and Houston.
Click on the house symbols here to learn more about the shelters’ location, hours and website.
Hurricanes can cause enormous damage and loss of life. With online maps you can help plan evacuation strategies and share your findings with decision makers.
Similar analyzes of natural disasters other than hurricanes are possible with GIS facilities.
What is the Model?
Models are methodical approaches to the processes of querying, analyzing and presenting real-world geographic information. Perhaps the best example of the model is the models made by construction companies to sell the construction. They are made in accordance with the planned reality.
Models within the scope of GIS, It varies from a simple data table to analysis processes, from spatial inquiries to relational approaches.
The hurricane example is actually a model. The movement of people over time has been analyzed by the data coming from cell towers and other sources .
Since geographical entities are located in Euclidean space, they are positioned with Cartesian coordinates. Geographical entities that can be represented as points, lines or polygons with the Euclidean model can be transferred to the GIS environment in two or three dimensions (Miller and Wentz, 2003).
The model is the abstraction of one or more processes that occur in the real world and presenting them with the help of GIS (Goodchild, 2005). For this reason, GIS is an important tool because of the opportunity it provides in solving problems related to geographical/spatial models and geographical phenomena, and the bridge it establishes between different disciplines and perspectives (Longley et al., 2005).
An educational map was also made due to the river overflows in Houston. : https://www.harriscountyfemt.org/
Here, the 100-year-old flood plains are shown in less risky in lighter blue.
The word model has basically two different meanings within the scope of GIS. The first of these is data modeling. In our Houston example, streams, rivers, streams and settlements come form the attribute table with their various attributes. A meaningful analysis and model is created by visualizing on the map with the groupings made in this attribute table.
Advances in GIS and computer technologies make models closer to reality. In particular, the layer logic in GIS makes the analysis easier to understand by visualizing it. In the Houston example, it is possible to talk about different layers such as the rivers layer, the cities layer, and the overflow properties layer. By placing them on top of each other, analysis can be done more easily.
One of the problems related to the subject is the sharing of these models. The lack of an accepted method of defining models and a central sharing area for models prevents their accessibility.
In this context, studies are carried out to establish standards and to develop the usage methods of various models.
Modeling types and data types should be in a separate article.
So what would you like to analyze?
Which path would you follow to do this analysis?
If you can write a short 2-3 paragraph article with your answers to these questions, I will share them on my website.
References:
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