Introduction to GIS

hello class and welcome to GIS for landscape analysis analysis I'm Tatiana Swindell be your instructor this semester so today I just want to give you a brief introduction into geographic information systems so what is G is G is by definition is a computerized system designed for the storage retrieval and analysis of geographically referenced data GIS uses advanced analytical tools to explore at a scientific level the spatial relationships patterns and processes of cultural biological demographic economic Geographic and physical trends and phenomenon basically it's a very sophisticated system that provides us with the ability to analyze the trends and patterns of our existing environment so G's for the where majority of data that we collect the data that you see on a map that has a location associated with it in addition to a location that data there's there's lots of information attached to that data what we call attribute tables and we'll get into that and there are many systems many components working together to achieve a common goal so if you see the image here this Google map on an Android it's a Google traffic app it's telling you information about your surroundings have you ever wondered how that information is collected basically if you have a cell phone then you are constantly transmitting information about your location now your cell phone provider has sold metadata about you to companies such as Google metadata meaning information that is probably just X Y coordinates of your location and so when there is a cluster of these points on a road and that information is overlaid with perhaps the speed limit of that road that is how we're gonna cap tell us when there's going to be a congestion or sometimes people will upload the fact that there is an accident on a road and so it becomes a point on the map so that's an example of a GIS so we'll be working mostly in this class with geographical features these are points lines polygons on a map that have information attached to them the hat that is usually information in form of a database table of some sort so remember GIS is not just software and it's not just for making map if I have principal components the software data methods people and the hardware in this class we'll be using the ESRI ArcGIS platform there are three basic capabilities in GIS that distinguish it from other programs that can generate similar outputs such as Maps for instance AutoCAD you can create maps in AutoCAD however it does not have these three basic capabilities that GIS does have one being that the data is spatially referenced in the way that we're able to do that is through a very scientific process that is map projections and cortan we use coordinate systems to be able to project our maps now we're not going to be car top professional cartographers however we do need to have a basic understanding of map projections in this course this is something that we will get a little further into throughout the semester but basically think of map projections as a way to take a feature so a polygon that perhaps represents a town or an area of interest such as a neighborhood and it's on a curved surface and somehow overlay that feature onto a flat surface there's a science behind that and that is something that digital cartographers have to go to school for many years to understand so we're not we're not going to really get too much into that but do understand a little bit about map projections we'll also be working a lot with coordinate systems and how coordinate systems are measured throughout the globe when you're dealing with features such as polygons a map projection is very important however when you're dealing with features such as points an exact point on a map an XY coordinate a map projection is not necessarily important you may not need it you may not even need to assign a map projection when dealing with just point data so this is something we'll get a little bit into further into the semester the other the second basic capability of GIS is that spatial data layers can be overlaid manipulated and combine to form composite layers this is a very powerful function of GIS so let's first begin by top spatial data is data which covers multidimensional points lines rectangle polygons cubes and other geometric objects often refer to as layers we will refer to spatial data in our course as layers now there are three basic types of spatial data that we will be using there is vector data which is a primary type of data that we'll be working with in this semester that's basically points lines polygons and tins secondly there is raster data that's when data is represented as a rectangular matrix of square cells and finally there is tap you excuse me and finally there is tabular attribute table data which is basically like an Excel spreadsheet that is attached to each feature on a map so layers represent in a special digital format features on above or below the surface of the earth vector data uses points and their XY coordinates and associated attribute eight data to represent spatial features or objects vector data uses points and their XY coordinates and associated attribute data to represent spatial features or objects that are on above or below the surface of the earth we represent vector data as lines on a map to represent roads or power lines each line is stored by the sweet sequence of the first and last point together with the Associated table attribute of this line so for instance if this diagram on the left here is line that represents power lines then the attribute for each segment so as you see there is a 2b that's segment a and then there's this this node to this node that's segment B and this node or point to this point that's segment C so there is associate information in an attribute table about each one of those segments so that could be capacity flow whatever information that there may be attached to that type of data we also represent data as points and each point is stored by its location XY coordinate together with its attribute for this point so if the point is a building then it would have perhaps a type of building height and vector data is also represented as polygons which is a sequence of lines that is closed so for instance a lake would be represented on the map as a polygon or a city or a neighborhood and the types of attributes in that app and that table would be perhaps the total area or the population of that area of that neighborhood and finally we represent vector data as tins this is where we are able to create 3d surface models of our environment tins or triangulated irregular Network is a vector based representation of the physical land surface or sea bottom the basic unit is a triangle used for service modeling we won't get too much into raster data in this semester but you know what raster data is it's basically when you represent the world as a grid of square cells the center of that cell will have an attribute this is often used for slope analysis and terrain analysis where each grid represents an elevation value and so you're able to determine perhaps what the slope is and where if you're designing perhaps a ramp or a walkway of some sort you'll know where you will need to have some sort of intervention if the slope does not meet meet design requirements naturally so all of these types of spatial data which we refer to as spatial data layers vector and raster and the attributes that are attached to it can be overlaid and manipulated using GIS yeah overlay analysis is a major part of GIS analysis so for instance if we want to take all of our spatial data layers to conduct an overlay analysis - perhaps study a crop yield you would overlay layers to create a composite layer so for instance this farmer wanted to find out where there would likely be low medium or high crop yield for his or her land and so they compared the salinity of water with incidents of disease perhaps it's added disease in vegetation or water with the water quality and they were able to using their own formulas for what happens when certain attributes of these features are come together to generate a map that tells us where you're going to have low medium and high likeliness of a crop yield the third capability of GIS is that spatial features are linked to tabular data using relational database this is an example of spatial features tabular data we're looking at a map that is showing all of the crime incidents that occurred between 2010 and 2015 each point of that map has an attribute table a spreadsheet with a record that relates that particular point on the map so let's take a closer look at that database table database tables in our course we were referred to primarily as attribute tables so an attribute table consists of a record for each feature on the map a field or actually multiple fields representing attributes of each feature on the map so each point each line each polygon each raster grid cell and records which are the actual information or the attributes within the field now this allows us to conduct compound attribute queries it's when compound attribute queries are very helpful when we're trying to extract information from a map so for instance if we want to know where all the drug related calls are after a certain date we would you do something called a query that's basically asking the map a question so the map on the Left is showing all of the crimes from 2010 to 2015 with in this neighborhood and the map on the right is showing you where are all the drug crimes from 2012 so as you can imagine this type of system is useful to many different types of businesses because the nature of most organization is that you get and your manage information you analyze that information and you create or recreate some kind of good or services or service GIS technology allows you to manage that geospatial information very very large quantities of geospatial information using attribute queries and many other tools that we'll get into the semester where we can easily analyze geospatial information and as a result were able to put together geospatial design GIS is actually the precursor for in emerging in an emerging field of study called geo design so GIS is used in many different industries from business defense education government natural resources mapping and charting Health and Human Services Public Safety transportation utility and communications I actually work for a turbine planning and consulting firm and GIS is the backbone of our department it's it's we would not be able to make the many millions that we make every year without having GIS as a tool there's always a process involved with working on a GIS project in its common to what refer to as end-to-end map making process we begin by defining a problem we then define that GIS criteria to solve that problem we import and build datasets of information we overlay those layers of of information and conduct GIS analysis we generate an output and we make a decision based on that on process have we solved our problem if not then we refine the problem and start the process again here's an example of a GIS process that is currently underway in Los Angeles so in 2005 city officials in Los Angeles California launched a major public works project focused on human dimensions of the river it was a land there was a landmark study damage that demonstrated a significant potential to improve quality of life for citizens living near the river corridor through wise redevelopment so their goal was to create pocket parks and landscape walkways to create places where children can play and adults can stroll so here's an example of the process that the GIS analysts involved in this project took to find the most optimal locations for this corridor for healthy living so they began with the mapping out where the river was they then created a proximity zone a tool that we call the buffer tool that is within a certain distance of the river of where they want to target to start greening its surroundings based on those proximity zones they created other proximity zones around existing parks so they took those two buffer zones and subtracted them from each other and that's how they identified this is exactly where we want to work this is where we need we are within a certain distance of the river and we also are not within an existing park they added boundaries that represent census boundary basically it's its boundaries that have information about the population such as how many people what are their ages what is the average income or median income and all that source of information and collect that information of the census blocks that are within their desired target areas so they had a very detailed list of criteria for the people and so the third step was to designate of that buffer zone or of that area that they want to build more parks where is the population more favorable or less favorable where are we likely going is this park likely going to get the most use based on that population and then the second part was to overlay municipal data so City data about property ownership and that is what we called parcels parcels are polygons that represent ownership of an area so they took parcels that are vacant and they tagged those as their priority parcels they selected all of those priority parcels and the population surround immediately surrounding those priority parcels and they were able to come up with a map that showed the most optimal locations within this corridor to build their next Park GIS is also a very important tool in landscape design and landscape analysis so the landscape architect's in this course this is something that I strongly recommend that you take this course very seriously it's a very important part of your field of study GIS tool the GIS is a great tool to help you understand the context how does it operate is it working well or not what is the process that we can take that that might alter the context and what differences might the changes caused and how should the context be changed as I mentioned early earlier there is any merging new field of study called geo design the director of the program is a very respected professor here at Philadelphia University he is a professor in a landscape architecture program Jim query and this is a quote his quote the future of design excellence and sustainability across the design disciplines will require ever-increasing complex problem-solving skills to empower creativity so GI geo design is basically smart design it's taking information that we learn from different types of GIS analysis and processes and making smart decisions so again GIS is a very important tool for the analysis of our existing environment it's used in many many fields of study in many industries and it's it's something that is a precursor to a new field of study called geo design so this concludes our introduction to GIS for landscape analysis I will be sending you a list of questions and instructions on how I would like you to answer those questions

Channel: Tatianna Swenda

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Length: 22min 31sec (1351 seconds)

Published: Sun Jan 17 2016